Enhancing Shielding Efficiency of Ordinary and Barite Concrete in Radiation Shielding Utilizations

doi:10.21203/rs.3.rs-4373910/v1

Download PDF

Article

Enhancing Shielding Efficiency of Ordinary and Barite Concrete in Radiation Shielding Utilizations

https://doi.org/10.21203/rs.3.rs-4373910/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 29 Oct, 2024

Read the published version in Scientific Reports →

You are reading this latest preprint version

Concrete has been used as a radiation shielding material due to its properties and integrity. Radiation shielding materials play a crucial role in various applications, ranging from nuclear power plants to medical facilities. Despite the prevalent use of concrete as a radiation-shielding material, uncertainties persist regarding the most suitable concrete grades for optimal attenuation, emphasizing the necessity for systematic investigation. In this study, we investigate the efficacy of ordinary and barite concrete as radiation shielding materials across different grades: M15, M25, M35, and M45. Ordinary concrete (OC), composed of cement, water, and limestone as aggregates, is compared with barite concrete (BC), where barite is added as an aggregate substitute to enhance radiation attenuation properties. An assessment is conducted on the physical attributes and gamma-ray attenuation characteristics of these concrete mixtures after exposure to Cobalt-60 and Caesium-137 radioactive elements. Key properties, including density, compressive strength, linear attenuation coefficient (µ), mass attenuation coefficient (µm), half-value layer (HVL), tenth-value layer (TVL), radiation protection efficiency (RPE), mean free path (MFP), radiation efficiency, and lead equivalent, were examined. The concrete is irradiated in a thermal column for 24, 48, and 72 hours to assess changes in crystalline size and lattice parameters following neutron exposure. The addition of barite as an aggregate substitute enhances the density, with the density of OC ranging from 2.1 g/cm³ to 2.39 g/cm³, accompanied by compression strength ranging from 20 MPa to 44 MPa. In contrast, barite concrete (BC) has a density ranging from 3.07 g/cm³ to 3.55 g/cm³, with compression strength ranging from 18.15 MPa to 39.71 MPa. Irradiation with Cobalt-60 reveals lower linear attenuation (µ) within the range of 0.172 to 0.195 cm^− 1, with consistent mass attenuation for all grades at 0.81 cm²/g. The HVL ranges from 3.559 cm to 4.020 cm, with a corresponding TVL spanning 11.825 cm to 13.354 cm. XRD testing reveals a shift in the SiO₂ and BaSO₄ peaks towards the right after irradiation, indicating crystalline expansion in size, with the most significant changes observed after 24 hours of irradiation. Concerning lattice parameters, the d-value (inter-atomic spacing) shows the most significant decrease of 0.10 after 48 hours of irradiation in grade 25, while the most notable increase is 0.02 after 24 hours of irradiation in grades 15 and 45. The experiment suggests that ordinary concrete is effective for radiation shielding against ¹³⁷Cs but lacks sufficient efficacy against ¹³⁷Co.

Physical sciences/Materials science

Physical sciences/Physics

ordinary concrete

barite concrete

linear attenuation coefficient

half value layer

crystalline size

and d spacing

Concrete is an excellent and versatile man-made construction material that serves as the primary construction material for reactor containment and shielding ^1,2. Concrete is a mixture of cement and aggregates (such as sand), with water and air. Typically, concrete contains 5–8% air, 7–15% cement, 14–21% water, and 60–70% aggregates^3,4. It comprises a blend of light and heavy elements and has good nuclear characteristics for photon and neutron attenuation^5,6. Concrete is utilized in nuclear power plant (NPP) construction for containment, structural foundation, and as the primary biological shields for the reactors⁷. Radiation shielding concrete plays a pivotal role in mitigating the harmful effects of ionizing radiation in various industrial and medical settings ⁸. The development of effective shielding materials is essential to ensure the safety of personnel and the environment in facilities such as nuclear power plants, medical imaging applications, and research laboratories ⁹. Concrete, due to its abundance, affordability, and ease of fabrication, has emerged as a primary choice for radiation shielding applications ¹⁰.

Radiation shielding concrete (RSC) is a high-density concrete (HDC) with densities greater than 2.9 g/cm₃, composed of dense aggregates with specific gravities of more than 3.0 g/cm₃ ^11–13. RSC can be designed to protect against both neutron and gamma radiation^{1 4–16}. It is the primary structure expected to receive radiation from nuclear power plants, as it is designed to absorb radiation and support the reactor vessel. RSC plays a crucial role in preventing radiation leaks, attenuating gamma radiation, and neutron radiation, and providing structural support for nuclear power plants and equipment during operation ¹⁷. Compared to conventional shields, RSC offers superior protection against gamma and neutron radiation hazards ¹⁴. Unlike lead, RSC does not generate secondary neutron rays through photo-neutron interaction while shielding high-energy gamma rays ¹⁸. The high density of RSC is achieved by replacing ordinary concrete aggregates with specific high-density aggregates or other materials ^12,18,19. Suitable materials for aggregate replacement include quartz ²⁰, heavy minerals like zircon, fly ash, and artificial aggregates such as iron waste ^2,6,21,22, tin tailing ²³, bismuth oxide, galena, bauxite, hydrous iron ore ^5,12,24, and recycled aggregates ²⁵. Combining various heavyweight aggregate materials like barytes^11,26,27, limonite^13,27,28, magnetite ^6,29,30, and ilmenites ^14,31 helps reduce section thickness while meeting attenuation requirements. The use of HDC as radiation shielding can reduce the thickness of RSC by almost 40% compared to ordinary concrete while maintaining load-carrying capacity ^12,32. RSC's high density and crystallized water content protect against various types of radiation, including beta rays, alpha rays, gamma rays, neutrons, and X-rays ³². The shielding properties of RSC have been extensively researched and proven by various researchers ^33,34.

A. Kmita ³⁵ classified concrete materials and manufacturing technologies into different categories based on strength, including conventional concrete (CC) up to grade 60 Mpa, high strength concrete (HSC) with grade 60–90 Mpa, very high strength concrete (VHSC), grades 90–130 Mpa, and reactive powder concrete (RPC) grades 200–800 Mpa. Concrete strength typically increases over time, with compressive strengths ranging from 20 to 60 MPa after 28 days of curing ³⁶. Concrete technology advancements have led to significant improvements in compressive strengths over the years. The properties of ordinary concrete and barite concrete are compared in Table 1 below:

Table 1

The properties of ordinary concrete and barite concrete
Properties	Ordinary concrete ³⁷	Barite concrete
Compressive strength (MPa)	22–40	20–60^6,38
Tensile strength	< 5	> 5
Flexural strength	< 6	> 6
Ductility	Nil	Nil
Impact loading	<UPHC	<UPHC
Abrasion loading	<UPHC	<OC ³⁹
Impermeability	Steady carbonation, chloride penetration	Nil

Ordinary concrete is commonly used for superficial and orthovoltage radiotherapy and megavoltage therapy rooms due to its low construction cost along with its functional properties to protect human beings from hazardous radiation³. However, it is not typically used as the sole barrier for NPP. In NPP, high-grade HDC is the primary protective barrier due to its superior properties and effectiveness^40,41. While ordinary concrete may not provide the same level of radiation attenuation as HDC in NPPs, recent studies have shown its effectiveness in optimizing radiation levels within lower radiation environments, such as research reactors ⁴². The minimum grade of concrete required is determined by durability factors, which are based on the kind of environmental conditions to which the structures are exposed ^35,43. A higher grade of concrete is suggested under adverse environmental exposure circumstances. The grades are recommended for different levels of exposure and extreme conditions ⁴³. For applications, such as large structures and reactors, the grade of concrete is often chosen primarily based on its strength rather than just its endurance ^35,43,44. Studies have shown that exposure to neutron fluence can lead to a reduction in compressive and tensile strength of concrete, as well as an increase in volume that causes the degradation ⁴⁵. However, neutron shielding evaluation proves that the effects on concrete properties are relatively small up to a neutron fluence of the order of 10¹⁹ n/cm², with higher fluences potentially causing harmful effects on compressive and tensile strength and elasticity ⁴⁶.In Malaysia, a research reactor known as TRIGA PUSPATI has been operated for more than four decades since its first critical with fast neutron fluences higher than E > 0.1 MeV, the biological shield will reach a level where the effect of radiation induces volumetric expansion (RIVE) and loss of mechanical properties that cause potential degradation mechanisms are expected ⁴⁷. This issue also raises concern about worker’s safety since the shielding containment as the biggest construction might degrade and leakage from radiation might happen as the most exposed structure to high radiation flux ⁴⁸.

This study aims to investigate the potential of fabricated ordinary concrete and barite concrete as shielding materials against radiation, with a focus on determining their efficiency in providing adequate protection. The primary objective is to analyse the physical properties of both ordinary and barite concrete to assess their suitability for manufacturing shielding materials and enhancing radiation shielding effectiveness. Furthermore, the research seeks to explore the alterations induced by radiation in concrete by investigating the degradation effects caused by irradiation on its crystalline properties in both types of concrete.

The methodology of this study involves several key steps to evaluate the effectiveness of ordinary and barite concrete as radiation-shielding materials in a research reactor environment. Initially, concrete samples of grades M15, M25, M35, and M45 (M denotes the mix or designated mixture to achieve the required compression strength after the 28th day of the curing process) are selected for fabrication using Tomaz Zagar’s ^42,49 mixing materials at the TRIGA research reactor in Ljubljana. The physical and mechanical properties of the concrete samples are assessed using gamma rays emitted by Cobalt-60 and Caesium-137. This analysis includes parameters such as linear attenuation coefficient, mass attenuation coefficient, mean free path, radiation protection efficiency, and lead equivalent. However, the assessment was limited to ordinary concrete due to the limited availability of barite concrete samples for this procedure. Nonetheless, the results obtained from ordinary concrete will be compared with those from barite concrete samples obtained from other research studies.

After the gamma-ray assessment, the concrete samples undergo irradiation in the thermal column at TRIGA PUSPATI at 750 kW for a maximum of six hours per day. The neutron irradiation is conducted to simulate the exposure of concrete to neutron flux in a research reactor environment. During this process, parameters such as neutron fluence and irradiation duration are carefully controlled. Following irradiation, the concrete samples are further analyzed to assess any changes in their physical and mechanical properties. Additionally, X-ray diffraction (XRD) analysis is used to determine the crystalline size and lattice parameters of the concrete samples before and after irradiation. This analysis helps investigate any post-irradiation effects on the concrete's crystalline structure. The methodology involves a comprehensive evaluation of ordinary concrete's suitability as a radiation-shielding material through a combination of gamma-ray and neutron irradiation experiments, followed by a detailed analysis of physical and mechanical properties, as well as crystalline structure using XRD.

2.1 Fabrication of Ordinary Concrete and Barite Concrete

In this study, Radiation Shielding Concrete (RSC) was produced using ordinary concrete and barite concrete of different grades: M15, M25, M35, and M45. Ordinary concrete consisted of sand as the fine aggregate and limestone (CaCO₃) as the coarse aggregate, with limestone particles ranging from 5 mm to 25 mm. The fine aggregate, sand, had a particle size of less than 1.35 mm. Barite concrete, on the other hand, used barite (BaSO₄) as both coarse and fine aggregate. The coarse aggregate consisted of barite particles ranging from 5 mm to 20 mm, while barite powder replaced sand as the fine aggregate. Portland cement type one and water were used in the concrete mix. The cement-to-water ratios for the different grades were 0.78, 0.58, 0.49, and 0.42, respectively. Concrete specimens were cut into sizes of 150 mm x 150 mm x 150 mm, with three samples per grade, and 150 mm x 150 mm x 750 mm for each ordinary concrete grade. More detailed information on the materials used in concrete production can be found in Table 2.

Table 2

Approximation of composition of materials usage for both concrete production
Type/grade of concrete	Percentage of Weight materials (%)
	Cement Portland	Water	Coarse aggregate		Fine aggregate
	Cement Portland	Water	Limestone	Barite	Sand	Barite
OC 15	10	8	39	-	43	-
OC 25	14	8	41	-	37	-
OC 35	16	8	42	-	34	-
OC 45	19	8	41	-	32	-
BC 15	10	8	-	39	-	42
BC 25	14	8	-	40	-	38
BC 35	16	8	-	42	-	34
BC 45	19	8	-	41	-	32

The concrete fabrication process involved several key steps. It began with weighing and mixing all materials in a concrete mixer. Water was gradually added until the cement mixture became cohesive, with a solidification time of 20 to 30 minutes. For barite concrete, which uses high-density aggregate, the mixing time was shorter to prevent segregation. After mixing, the concrete was placed into a moulded container. For a 150 mm x 150 mm x 150 mm size, the moulded container was placed on a grinding machine for compression. For a 150 mm x 150 mm x 750 mm size, a portable vibrator was used for consistent vibration to remove air pockets and increase density and strength¹⁷. The curing process involved placing the hardened concrete in a curing tank of water for seven days. Afterward, the concrete was removed from the water and left at room temperature for an additional 21 days to complete the curing process as in Fig. 1:

Figure 1: Flowchart of concrete-making process from designing to experimental procedure.

2.2 Pre-radiation Test

Density and compression strength test

The density and strength of concrete vary depending on factors such as the amount and density of the aggregate, the presence of trapped air, the concentration of cement, and the maximum size of the aggregate used ^50,51. Compression strength, defined as the maximum resistance measured by a concrete specimen to an axial load, is a crucial property of concrete ^50,51. Concrete compression tests involve subjecting concrete to a 250 kN load using a compression machine across its surface area. After the compression strength test, the quality integrity between cement pastes and aggregate particles in the concrete is evaluated. Compression strength serves as a fundamental property used for both design and quality control in concrete applications. The density and compression strength are measured according to standard procedures outlined in Table 3.

Table 3

Detailed of the physical test for concrete
Strength test	Amount of sample test	Day of test	Size (mm)
Density	24	28	150x150x150
Compression	24	28	150x150x150

The Density test was conducted by measuring the average weight of concrete. The test is conducted immediately after concrete reaches the age of 28 days. Concrete will be calculated by diving the mass (m) with volume (V) as in Eq. 1 ²:

$$\rho =\frac{m}{v}$$

…

The concrete compression test was carried out after a density test using a compression machine at the Malaysian Nuclear Agency. The concrete will be given a pressure of 250KN by a compressor over the surface of the concrete. Based on the following formula, the pressure is given to concrete to determine concrete density. The following Eq. 2^,52

$$F=\frac{P}{A}$$

…

where F is The compressive strength (MPa), P is the Maximum load (or load until failure) to the material (N) and A is a cross-section of the area of the material resisting the load (mm²).

Radiation Attenuation Test

The radiation attenuation test was conducted at the Nuclear Science Laboratory at the School of Science and Technology at the National University of Malaysia. To measure gamma ray attenuation, a sodium iodide NaI (Tl) scintillation detector coupled with a Multi-Channel Analyzer (MCA) was utilized. For this study, ¹³⁷Cs and ⁶⁰Co were selected as gamma photon sources to evaluate the radiation attenuation properties of the concrete. The choice of these sources was based on their gamma emission energies, which cover the relevant energy range for diagnostic and therapeutic applications. Specifically, ¹³⁷Cs have a half-life of 28.44 years, while ⁶⁰Co has a half-life of 5.26 years, with photon energies of 0.662 MeV for ¹³⁷Cs and two energy levels (1.173 and 1.333 MeV) for ⁶⁰Co ⁵³.

The experimental setup, depicted in Fig. 2, involved positioning test samples of varying thickness (ranging from 20 to 100 mm) in the path of a collimated beam emitted from the gamma-ray sources. Each sample underwent measurements for 20 minutes. Initially, the detector was calibrated, and the initial count rate (N₀) was determined in the absence of a concrete sample, with the source-detector distance set at 24 cm. Subsequently, the concrete samples, each with different thicknesses, were placed between the detector and the source to assess their shielding efficiency against gamma radiation.

Figure 2: Illustration of the experimental setup in the laboratory for the radiation attenuation test

Linear and mass attenuation coefficient

The probability of gamma-ray interaction with a material per unit path length is defined by linear attenuation coefficient (µ). The gamma ray's attenuation coefficient, determining the fractional radiation intensity I about the source intensity I₀ through the thickness x, was calculated. The µ was derived from the solution of the exponential Beier Lambert's law ⁶ as Eq. 3:

$$\frac{I}{I0}={e}^{-\mu x}$$

…

I₀ is the gamma-ray intensity at zero absorber thickness, I is the gamma-ray intensity transmitted through an absorber of thickness meanwhile µ, x is the linear attenuation coefficient.

The mass attenuation coefficient (µm) describes the average number of interactions that occur between incident photons and matter. Determination of the mass attenuation coefficient of the materials was performed by dividing the linear attenuation coefficient of the material by the density (ρ) of the material according to Eq. 4 ⁵⁴

$$\mu m=\frac{\mu }{\rho }$$

…

Half-value and tenth-value thickness layer

The concept of HVL and TVL is very useful in doing rapid, approximate shielding calculations. Measured linear attenuation coefficients of different densities of concretes are the Half-value layer (HVL) and the tenth-value layer (TVL) are the thicknesses of an absorber that will reduce the gamma radiation to half and to the tenth of its intensity, respectively ⁵⁵. Those are obtained by using the following equations ^6,55,56

HVL=$\frac{\text{ln}2}{\mu }$ …(5)

TVL=$\frac{\text{ln}10}{\mu }$ …(6)

Radiation protection efficiency (RPE) and lead equivalent.

Radiation protection efficiency (RPE) is an important parameter that gives information on the shielding ability of the proposed material. in other words, the RPE % value is a significant parameter to show shield efficiency % to protect against radiation and It can be determined as shown in Eq. 5⁷

RPE=$\left(1-\frac{I}{I0}\right) X100$ …(7)

The linear attenuation coefficient of concrete varies depending on its density and composition. Lead equivalent is measured. To calculate the lead equivalent of concrete, the following formula can be used ⁵⁸:

$$Lead equivalent=\left(\frac{\left(\mu \right) Pb}{\left(\mu \right) concrete}\right) x \left(thickness of materials\right)$$

…

Where (µ) Pb 0.596 cm^− 1

2.2 Neutron irradiation

This study investigates the direct effects of neutron irradiation on concrete, focusing on the degradation levels over specific time intervals. The irradiation was conducted at the RTP thermal column of the Malaysian nuclear agency, with durations of 24, 48, and 72 hours intermittently. Each sample, averaging 1.62 g, was carefully enclosed in a polyethylene container, wrapped with parafilm, and placed within the thermal column until the desired radiation duration was achieved. Radiation exposure occurred daily for four to five hours, over four days per week, spanning up to five weeks at a power level of 750 kW. The radial beam port consists of seven thermal columns, with six featuring six holes each and one central column containing 13 sample holes, totaling 49 holes for sample placement as in Fig. 3. For this study, 40 samples, with five from each grade, will be accommodated in parallel columns. Each sample undergoes irradiation at a power level of 750 kW for several hours daily until the specified exposure time is reached.

After the irradiation period, concrete samples are transported back to the National University of Malaysia (UKM) in specialized containers to prevent contamination. The samples are stored until they reach a safe radiation level below 1 mSv, which typically takes two to six weeks based on concrete readings. Once the radiation levels are safe, the concrete is transferred to a glass container and undergoes the x-ray polishing process.

Figure 3: The arrangement of the concrete sample experimental in the thermal column at TRIGA PUSPATI

X-ray Diffraction Test (XRD)

The X-ray diffraction (XRD) test was conducted at the Instrumentation Laboratory of the National University of Malaysia (UKM). The samples, delivered in powder form, underwent XRD analysis with the primary objective of identifying the phase, crystal size, and lattice parameter of the material within concrete. Additionally, XRD aimed to provide qualitative and quantitative analyses of crystalline compounds for various grades of concrete before and after irradiation.

The XRD analysis utilized a Bruker model D8 Advance with Cu Kα (λ = 1.5406 Å), employing the XRD technique with a diffraction angle (2ϴ) ranging from 10 to 80°. Synchronized rotation of the sample ensured uniform exposure of each particle to the X-rays. A graph correlating intensities with rotation angles was generated to evaluate the crystallinity of the sample. The degree of crystallinity was determined by integrating the areas under the curves, with the peak area directly proportional to the degree of crystallinity ⁵⁹. Concrete samples sent to Centre of Research, Instrumentation, and Management (CRIM) labs were intended to capture the changes occurring in a material after absorption over a specific period. The XRD method revealed alterations in peak characteristics for specific elements present in concrete before and after polishing. Furthermore, changes in crystal size, density shift, and concrete micro strain were observed through XRD, making it a valuable technique for analyzing the crystalline size and lattice parameters to assess the degradation of concrete following irradiation.

Lattice Parameter

The lattice parameter of a crystal is not directly applicable to concrete because concrete is a heterogeneous material made up of various components, including aggregates, cement, and water. The concept of lattice parameter is typically used in the context of crystalline materials to describe the physical dimensions of the repeating unit cell in a crystal lattice ⁶⁰. Hence, the formula for calculating the lattice parameter is not directly applicable to concrete. For lattice parameter measurement, the method involves indexing the peaks of the elements, known as Miller indices. This index miller is obtained from the Joint Committee on Powder Diffraction Standards (JCPDS). For SiO2 in ordinary concrete, the evaluation was conducted using JCPDS No. 4041 − 1413, and for barite concrete, the evaluation of BaSO₄ was done using JCPDS No. 24-1035.

Since then, the calculation of the d-value (distance between adjacent lattice planes) in a crystal lattice is determined by Bragg's Law ². Bragg's Law establishes a relationship between the angle of incidence of X-rays or neutrons on a crystal and the spacing of crystal lattice planes. This formula is commonly used in XRD or neutron diffraction studies to determine the spacing between crystal lattice planes based on the observed diffraction pattern. The d-value provides information about the crystal structure and spacing in the material based on the equation below ⁶¹ .

$$d=\frac{\lambda }{2\text{s}\text{i}\text{n}\left(ϴ\right)}$$

…

Where ϴ is the angle of incidence, and λ is the wavelength of the incident radiation.

Crystal Size

Crystal size plays a significant role in evaluating the changes that occur after the irradiation process. The crystal size is calculated directly from the average of the peaks using the Debye-Scherrer formula, as described by Sagayaraj et al ⁶² as shown below.

Crystalline size (D)= $\frac{K\lambda }{\beta COSϴ}$ … (10)

K is the Scherrer constant. The actual k value increases from 0.62 to 2.08, while the commonly used value for k is 0.9464 ⁶³. Meanwhile, in this study, the k-value used is 1.0. This value has been set in the software utilized in the research laboratory (fixed in the DIFFRAC software). λ represents the wavelength of 0.15406 nm, while β refers to the full width at half maximum (FWHM) or integral breadth from the peak, and ϴ denotes the peak position (in radians) or axis angle of the elements.

4.1 Physical Properties of Concrete

Density Concrete

The density and strength of concrete can be determined after the 28th day of the curing process when it reaches a stable strength value. The density of concrete is a crucial factor in determining porosity, assessing durability and strength, and estimating lattice constants for the CSH phase in hydrated Portland cement⁶⁴. Different types of aggregates used in concrete result in varying density and strength of the concrete. The density of ordinary concrete obtained from this experiment is calculated and tabulated in Table 4 below.

Table 4

Difference in the density of ordinary and barite concrete after the 28th day of the curing process
Grade of concrete	Density (g/cm³)
Grade of concrete	Ordinary concrete	Barite concrete
15	2.27	3.29
25	2.13	3.23
35	2.39	3.55
45	2.29	3.07

Based on Table 4, barite concrete has a higher density than ordinary concrete. Ordinary concrete in this research has a density range from 2.13 g/cm³ to 2.39 g/cm³ and has a density below 2.5 g/cm³ ^14,46, which is in the range of normal-strength concrete. Normal strength concrete typically ranges from 2.2 g/cm³ to 2.5 g/cm³. Another study by Mortazavi and Raadpey ³ showed that ordinary concrete has a density ranging from 2.3 g/cm³ to 2.5 g/cm³. Grade 35 concrete has the highest density among all types of concrete, measuring 2.39 g/cm₃. The density of concrete is influenced by the density of the aggregate. Since limestone (CaCO₃) has a typical aggregate weight of 2.71 g/cm³, the density of concrete falls within the standard density range ⁶⁵.

Barite concrete exhibits densities ranging from 3.07 g/cm³ to 3.55 g/cm³, placing it within the high-density spectrum of concrete materials. This increased density is attributed to the inclusion of barite, a heavy mineral with a density of 4.48 g/cm³ ^27,41. Consequently, the density of barite concrete surpasses that of ordinary concrete by approximately 45% ⁴¹. This significant increase in density highlights the effectiveness of barite as a heavyweight additive in improving the shielding capabilities of concrete against radiation. Studies comparing ordinary concrete with barite concrete have demonstrated that barite concrete can achieve densities of up to 3.5 g/cm³ ²⁷. However, research by Murtafi'atin et al ⁶⁶ suggests that the use of barite as an aggregate for shielding materials in the medical field has not consistently resulted in densities of 3.0 g/cm³. Conversely, Akkurt et al.'s research indicates that the incorporation of barite as an aggregate can achieve densities of 3.4 g/cm³. In comparison, RTP biological shielding concrete is reinforced concrete with a density of approximately 3.42 g/cm^{3 26,67}. These findings suggest that incorporating heavyweight aggregates in concrete construction has the potential to increase material density, thus enhancing its shielding effectiveness against radiation. These heavyweight aggregates demonstrate improved shielding performance against gamma ray and neutron radiation, making them valuable for various applications, including nuclear power plants, X-ray imaging rooms, and radioactive storage facilities³².

Compression strength

Like density, compressive strength is also calculated after the 28th day of the curing process when it reaches stability in compression. Nearly all the researchers included compressive strength as one of the parameters under investigation. The compressive strength of concrete structures is a critical mechanical parameter that indicates the overall performance based on the quality of concrete. The compressive strength of concrete is influenced by many factors such as water/cement (w/c) ratio, mix properties, type and size of aggregate, curing conditions, as well as the shape and size of the test specimens⁶⁸. Density and compressive strength are two different properties. Having high density does not necessarily mean that the concrete will have high compression strength. However, denser concrete generally provides higher strength. The relationship between density and strength is influenced by various factors. It is possible for concrete with additives to exhibit enhanced properties, such as improved radiation shielding, without necessarily having a higher density.

The compressive strength also depends on the strength of the aggregate itself. The compressive strength of concrete is a crucial property not only for designing structural concrete but also for compliance purposes, serving as a key parameter for field quality control ⁶⁴. The compressive strength of ordinary concrete is shown in Fig. 4:

Figure 4: Comparison of compression strength between ordinary concrete and barite concrete after the 28th day

The compressive strength of concrete varies significantly across grades, ranging from 20.24 MPa to 44.44 MPa for ordinary concrete and 18.15 MPa to 39.71 MPa for barite concrete. This observation confirms that ordinary concrete generally exhibits higher compressive strength compared to barite concrete. Both types of concrete fall within the medium compressive strength category, typically ranging between 20 to 50 MPa ⁶⁹.

Grade 15 exhibits the lowest strength, while Grade 35 demonstrates the highest compression strength for ordinary concrete, and Grade 45 for barite concrete. Each grade, except for grade 45, exceeds its estimated strength, with approximately 15 MPa for M15, 25 MPa for M25, and 35 MPa for M35. Despite Grades 15, 25, and 35 exceeding their approximate strengths, Grade 45 falls short of meeting the required limit. It is important to note that this type of concrete is not consistently characterized by exceptionally high compressive strength. Factors such as the water-cement ratio, curing conditions, and the type of aggregates used can influence the strength of concrete⁷⁰. Further reduction in compression strength can also be influenced by factors such as temperature, weather conditions, and the size or distribution of coarse aggregates used ^71,72. In the case of concrete constructed under similar conditions and surroundings for both ordinary and barite concrete, weather and temperature variations are not the primary contributors to the strength reduction observed in ordinary concrete. Ortiz et al⁷³ proposed another factor that could contribute to the reduction in compression strength is the microstructure of concrete, which affects its properties, morphologies, and the distribution of hydrated products within the cement matrix. Understanding the interplay of these factors is crucial for optimizing the mechanical performance of concrete in various environmental conditions.

Research by Gallala et al ⁷⁴ also showed a reduction in compression strength after mixing it with barite as an aggregate. Barite, renowned as a heavyweight aggregate, boasts remarkable density but is susceptible to brittleness and can easily fracture under high compression ⁷⁵. Many studies have investigated the effects of incorporating barite into concrete. This typically involves substituting both sand and gravel, which are primary components of ordinary concrete, to maximize the barite content. However, such substitutions have been found to have adverse effects on the mechanical strength of concrete, primarily due to the higher sensitivity of barite to abrasion compared to ordinary limestone aggregates ⁷⁶. Previous research indicates that mineral admixtures initially reduce the early strength of concrete, with the rate of reduction significantly diminishing over extended curing periods ^59,77–80. Consequently, it is ideally suited for non-structural constructions such as shielding walls, where structural load-bearing capabilities are unnecessary. However, its high density and resistance to radiation make it a prime candidate for RSC, where its primary function is to attenuate radiation without the need to bear significant mechanical loads^39,75. Despite this, regular concrete usually demonstrates relatively high compressive strength, allowing it to withstand breaking under compressive forces. This strength is crucial in design, influencing the structural integrity, load-bearing capacity, and overall performance of concrete elements⁸¹. The compressive strength plays an important role in design, as it is a crucial parameter in the design of concrete structures. It can influence the structural integrity, load-bearing capacity, and overall performance of concrete elements.

3.2 Radiation Attenuation Test

An effective radiation shield should have the ability to attenuate, absorb, or block a significant portion of incoming gamma radiation³⁹. Understanding the nature and mechanisms of interaction between gamma rays and materials is essential for evaluating their effectiveness in dispersing and confining radiation within a medium. This knowledge aids in choosing the most appropriate radiation shield based on the predominant interaction mechanism. Since a gamma ray is uncharged and has no mass, it can easily penetrate materials. Therefore, shielding against these photons is a crucial consideration. Materials intended for use as shields against gamma photons should have higher atomic numbers and densities. These characteristics increase the likelihood of interactions, resulting in greater energy transfer from gamma rays to the shielding material. A gamma spectrometer was used to assess the fabricated samples for gamma radiation. Gamma-ray sources were used to test the linear attenuation coefficients (µ) with various thicknesses of ordinary concrete exclusively. Table 5 includes a detailed calculation of concrete after irradiation, including measurements of the linear attenuation coefficient (µ), mass attenuation coefficient (µm), calculations of the half-value layer (HVL), and tenth-value layer (TVL).

Table 5

Mechanical properties of ordinary concrete for gamma test
Grade	Density (g/cm³)	Xray sources	µ (cm^− 1)	µm (cm²/g)	HVL (cm)	TVL (cm)
15	2.27	Co-60	0.184	0.081	3.768	12.520
25	2.13		0.172	0.081	4.020	13.358
35	2.39		0.195	0.081	3.559	11.825
45	2.29		0.185	0.081	3.745	12.443
15	2.27	Cs-137	0.285	0.125	2.435	8.091
25	2.13		0.274	0.129	2.527	8.396
35	2.39		0.292	0.122	2.376	7.895
45	2.29		0.291	0.127	2.378	7.902

Linear attenuation coefficient

The definition of µ is the probability per unit thickness that incident photons interact in a material. The µ measures how well a material can reduce radiation intensity as it passes through it. This concept is fundamental to the design and selection of materials for radiation shielding purposes. Based on Table 5, it found linear attenuation coefficient for ¹³⁷Cs is higher than ⁶⁰Co. The highest µ for ¹³⁷Cs is 0.292 cm^− 1 for grade 35 and the lowest µ in ¹³⁷Cs is 0.274 for grade 25. For ⁶⁰Co, the difference between the highest and the lowest µ is around 12%, which is double from the ¹³⁷Cs. Concrete grade 35 exhibits the highest density among the various grades, whereas grade 25 demonstrates the lowest density. It is well-established that materials with higher density tend to possess higher linear attenuation coefficients (µ) compared to those with lower density ^6,27,38. This relationship implies that higher linear attenuation coefficients indicate greater effectiveness in attenuating or reducing radiation. Put simply, a higher value of µ signifies increased photon interaction or reduced penetration depth. In characterizing γ-ray penetration in a material, the value of µ plays an important role depending on the photon energy and the density of the shielding material ^5,82. Researchers ^13,83,84 also conclude that µ of ¹³⁷ CS has higher µ compared to ⁶⁰Co when tested with concrete.

To ensure fairness, a comparison between ordinary concrete and barite concrete as shielding materials was conducted based on several research studies, as summarized in Table 6. The barite concrete specimens selected for comparison had densities exceeding 3 g/cm³. As anticipated, higher-density concrete exhibited greater linear attenuation. During irradiation testing, it was observed that higher-energy radiation sources resulted in decreased linear attenuation coefficients. This trend is attributed to the behavior of high-energy photons, particularly those with higher MeV (mega-electron volts), which tend to undergo interactions such as Compton scattering and pair production rather than complete absorption within the shielding material ⁸⁵. These interactions allow high-energy photons to penetrate shielding materials more effectively, resulting in lower linear attenuation coefficients compared to low-energy photons. Conversely, low-energy photons are more readily absorbed within the shielding material, primarily through interactions such as photoelectric absorption ⁸⁵. This mechanism involves the complete absorption of the photon by an atomic electron, resulting in higher linear attenuation coefficients for low-energy photons compared to their high-energy counterparts.

Table 6

Comparison of the linear attenuation coefficient of barite concrete from another research
Authors	Density	Sources	µ (cm^− 1)
Khaldari et al⁸⁶	3.49	⁶⁰Co	0.1862
	3.452		0.1872
	3.350		0.1806
Al-Humaiqani et al ⁸⁴	3.372	0.663 MeV	0.2446
Al-Humaiqani et al ⁸⁴	3.383	0.663 MeV	0.2369
Daungwilailuk et al ⁸⁷	3.807	0.662 MeV	0.27
		1.174 Mev	0.21
		1.332 MeV	0.20
	3.774	0.662 MeV	0.26
		1.174 Mev	0.20
		1.332 MeV	0.18
Izaz ahmad et al ³⁸	2.68	⁶⁰Co	2.68
	2.72		2.72
	2.78		2.78
	2.81		2.81

Half value and tent value layer

The Half-Value Layer (HVL) and Tenth-Value Layer (TVL) depend on the energy of the radiation and material properties, such as density and atomic number. HVL is not only composition-dependent but also dependent on the density of the material, which is further related to the structural arrangements of the constituents of the composite material l⁸⁸. This parameter is crucial for selecting materials to be used as radiation shields. With an increase in material thickness, the HVL and TVL also increase, requiring more material to achieve a fifty or ten percent reduction in radiation intensity. This is attributed to the increased likelihood of interaction between radiation and the material as its thickness increases. Consequently, an increase in material thickness amplifies the probability of radiation-material interaction, leading to a more significant reduction in radiation intensity. The correlation between material thickness and HVL or TVL is crucial in radiation shielding design, providing valuable information on the necessary amount of material to reduce radiation intensity to a safe level.

Figure 5 illustrates the variations in the Half-Value Layer (HVL) and Tenth-Value Layer (TVL) of ordinary concrete for 60Co and 137Cs across different grades. It is observed that the HVL and TVL values are lower for 137Cs compared to 60Co. Specifically, the highest HVL and TVL values are recorded for grade 25, measuring 4.02 cm and 13.358 cm, respectively, both for 60Co. Conversely, the lowest values are observed in grade 35, with HVL and TVL values of 2.376 cm and 7.895 cm for 137Cs. Additionally, it is noted that the HVL and TVL values decrease with increasing concrete density. This trend aligns with findings from previous studies that also established an inverse relationship between HVL and TVL values and concrete density ^2,46,89.

Figure 5: the value of HVL and TVL for ordinary concrete of various grades.

In his study, Ouda ⁶ demonstrated that the thickness of concrete significantly influences both the HVL and TVL, showing an inverse relationship between them. Ouda investigated the impact of concrete thickness on radiation attenuation using barite and magnetite concrete when exposed to 137Cs and 60Co. Specifically, in mixes M1 (incorporating sand) and M4 (incorporating magnetite aggregate), it was observed that the HVL and TVL values decreased with increasing concrete thickness for 137Cs and 60Co, respectively. This inverse relationship suggests that lower HVL and TVL values indicate more effective radiation shielding materials in terms of thickness requirements. Notably, for the 137Cs source, the HVL and TVL values for mix M4 were lower compared to mix M1 at the same energy level.

Meanwhile, Akkas⁹⁰ compiled data comparing different types of concrete, including ordinary concrete (ρ = 2.46 g/cm³) and high-density concrete (ρ = 3.463 g/cm³) under irradiation at 1173 KeV and 1332 KeV. For ordinary concrete, the half-value layer (HVL) and tenth-value layer (TVL) values were 3.98 cm and 13.23 cm for 1173 KeV, and 4.20 cm and 13.95 cm for 1332 KeV, respectively. In contrast, high-density concrete exhibited lower HVL and TVL values compared to ordinary concrete, with values of 3.85 cm and 12.79 cm for 1173 keV, and 4.08 cm and 13.54 cm for 1332 keV. These findings highlight the superior radiation shielding properties of high-density concrete compared to ordinary concrete.

Mean free path (MFP)

MFP is the average distance a photon can travel in the shielding material before being interacting. The mean free path has been determined using the linear attenuation coefficient relation. MFP refers to the average thickness of the material interacted with by the photon between two consecutive events (scattering or absorption).⁵⁶. The variation of MFP values with gamma energy for ordinary concrete is depicted in Fig. 6.

Figure 6: Mean free path of ordinary concrete.

The OC 35 exhibits the lowest mean free path (MFP) values, measuring 3.429 cm for 137Cs and 5.135 cm for 60Co, while grade 25 demonstrates the highest MFP, recording 3.646 cm for 137Cs and 5.801 cm for 60Co. A lower MFP indicates that particles are more prone to interactions or collisions within the material over shorter distances, whereas a higher MFP suggests that particles travel longer distances between interactions. In the context of radiation shielding, a higher MFP implies that the material allows radiation to penetrate through without significant attenuation, while a lower MFP suggests stronger attenuation and absorption of radiation within the material ⁵⁶. Grade 35, with the highest density, and grade 25, with the lowest density, highlight these differences in this study.

Furthermore, Al-Ghamdi⁹¹ observed that specimens containing additive materials, such as WO3 and barite, exhibited lower MFP values compared to control concrete (ordinary concrete). Examination of the impact of WO3 on MFP revealed a notable decrease in MFP for the prepared specimens. These findings suggest that incorporating WO3 in concrete specimens can reduce MFP and enhance radiation protection performance. In other words, MFP decreases with specimen density, indicating that high-density concrete absorbs gamma photons more effectively than lower-density samples.

Radiation protection efficiency (RPE)

Radiation protection efficiency (RPE) refers to the ability of materials or structures to reduce the intensity of ionizing radiation, thereby minimizing the risk of harm to humans exposed to the radiation ⁵³. The importance of the RPE lies in the fact that it gives a clear indication about the possibility of using the prepared specimens in radiation shielding applications. The choice between low and high radiation protection efficiency materials depends on the specific requirements of the radiation exposure scenario. In other words, high RPE is desirable because it provides greater safety for those working near or with radiation sources. Materials with high protection efficiency are crucial in environments with higher radiation intensity, ensuring optimal shielding to minimize the risk of harmful effects from ionizing radiation exposure ⁵⁷. Several factors contribute to radiation protection efficiency, including the type of radiation, the shielding material used, and the thickness of the shielding material ⁹¹. The calculated result has been plotted in Fig. 7 below.

Figure 7: Radiation attenuation efficiency of ordinary concrete

Based on the data presented in the figure, the RPE for ¹³⁷Cs is higher than that of ⁶⁰Co, especially in grade 25 where the RPE is ten times greater than that ⁶⁰Co. To achieve high radiation protection efficiency, materials with high atomic numbers and densities like lead or concrete with heavy aggregates are typically used. Al-Ghamdi's ⁹¹ research emphasized the importance of the optimal amount of WO₃ in enhancing radiation protection performance in concrete. The concrete sample with WO₃ demonstrated an RPE of 99% at 0.122 MeV, effectively blocking almost all incoming photons at that energy level. Similarly, at 0.356 MeV, the RPE for this concrete was 80%, intercepting a significant portion of photons at that energy level.

However, the RPE values in our study are relatively lower, especially for ⁶⁰Co, where all values are below 10%. This suggests that this type of concrete may not be suitable for shielding against high-energy gamma rays. The highest RPE for ¹³⁷Cs is below 50%, indicating that ordinary concrete can only intercept 40% of incoming photons. El-Sawy ⁵⁷ also conducted research using fiber composites as radiation shielding for various nuclear facility applications, including repairing cracks in the biological shields of nuclear reactors. Four different fiber composites were tested, with RPE% values of 43.1% for fiber with lead (FPPb), 37.2% for cement-fiber-magnetite (CFM,) 30.2% for natural fiber (FP), and 20.2% for cement fiber (CF). These results are consistent with FPPb showing the highest RPE% and CF having the lowest value, remaining below 50% RPE.

Lead Equivalent

The lead equivalence of radiation shielding materials is essential in determining their effectiveness in reducing ionizing radiation. Lead equivalence indicates the thickness of lead that provides the same level of attenuation as the material being used. This metric is valuable for comparing the effectiveness of various radiation shielding materials and thicknesses. The thickness of lead or lead-equivalent materials directly impacts their ability to absorb and block radiation effectively. Higher lead equivalents correspond to thicker shielding materials, leading to better radiation protection. In the provided figure, ⁶⁰Co has a lower lead equivalent compared to ¹³⁷Cs in Fig. 8.

Figure 8: Lead equivalent of ordinary concrete

The experimental analysis of ordinary concrete revealed significant differences in lead equivalence between ¹³⁷Cs and ⁶⁰Co sources. Grade 35 showed the highest lead equivalent at 5.397 mm for 137Cs, followed by 5.348 mm, 5.247 mm, and 5.008 mm. In contrast, ⁶⁰Co protection had lower lead equivalents, with the highest values at 4.180 mm, 4.017 mm, 3.947 mm, and 3.691 mm. None of the cobalt 60 lead equivalents exceeded 5 mm. A higher lead equivalent indicates better radiation attenuation, suggesting that denser materials or those with higher atomic numbers are more effective in absorbing and dispersing radiation ⁹².

Illustratively, a material with a lead equivalent of 5 mm provides radiation shielding equivalent to a 5 mm thick layer of lead, making it crucial for radiation protection in medical facilities, nuclear installations, and industrial settings with radiation hazards t⁵⁸. Materials with low lead equivalents like 0.25 mm or 0.35 mm offer basic radiation protection for low-intensity radiation environments. On the other hand, materials with higher lead equivalents of 0.5 mm or more provide superior shielding capabilities suitable for environments with high radiation intensity or prolonged exposure to ionizing radiation ^93,94. These findings highlight the importance of lead equivalents in designing effective radiation shielding measures to ensure the safety of personnel in various radiation-prone environments ⁹² .

3.2.1 XRD Result

Investigating the mechanical behavior of materials under various loading conditions relies on predicting outcomes based on structural information, which can be obtained through X-ray diffraction (XRD) analysis. This study utilizes XRD analysis to investigate the effects of gamma radiation on ordinary and barite concrete, enhancing our understanding of material responses. The XRD technique allows for the evaluation of changes in concrete caused by irradiation, including the assessment of crystallite size and lattice parameters. This analysis reveals alterations in the crystal lattice structure of silica before and after irradiation. Figures 9 and 10 below present XRD analysis comparisons for grades 25 and 45 of ordinary concrete.

Figure 9: XRD graph of ordinary concrete grade 25 before and after irradiation

Figure 10: XRD graph of ordinary concrete grade 45 before and after irradiation

Based on the comprehensive XRD examinations conducted on ordinary concrete, the analysis unequivocally reveals that the predominant element peak is attributed to quartz or silica oxide (SiO₂). Additionally, the presence of albite (NaAlSi₃O₈) was consistently detected across all grades of concrete. Furthermore, microcline (KAlSi₃O₈) and bismuth were also identified in the XRD analysis. Among these elements, quartz, recognized as silica, exhibits the highest peak intensity in XRD spectra. The presence of the crystalline phase (natural quartz) is noted to match the sharp peaks observed at 26.64° (OC15), 26.66° (OC 25), 26.40° (OC35), and 26.44° (OC45). This silica component is likely sourced from the fine aggregate, primarily silica sand, utilized in concrete production. Conversely, microcline and albite are secondary elements inherent in Portland cement. Moreover, the incorporation of limestone, containing calcium and carbonate ions, may contribute significantly to the presence of microcline and albite. The fundamental structures consist of interconnected SiO₄ and AlO₄ tetrahedrons, forming the backbone of the crystalline framework ⁹⁵. Most of the detected elements originate from the constituent materials employed in concrete production, including sand, Portland cement, limestone aggregate, and water.

Notably, the XRD examinations revealed a noteworthy phenomenon wherein all peaks corresponding to SiO₂ and other elements exhibited a rightward shift post-irradiation. The tendency of the peak to shift toward higher angles accompanied by bigger peak features gives a different indication of movements toward a crystalline structure and orientation differently from what was reported by some other researchers ⁹⁶.

The XRD analysis of barite concrete has been presented in Fig. 11 to 12 below for grade 15 and grade 35. Grade 25 and 45 have identical results with the grade 15 and grade 35.

Figure 10: XRD graph of barite concrete grade 15 before and after irradiation.

Figure 11: XRD graph of barite concrete grade 35 before and after irradiation

Based on the XRD analysis of barite concrete, it is evident that the prominent element peaks indicate the presence of barium or BaSO₄ as the primary constituents, with no other elements detected. The sharp peaks observed in the concrete match the presence of barite, which is used as both coarse and fine aggregate in the mix, comprising over 70% of the structure. Secondary elements typically found in concrete, such as albite and microcline, were notably absent in the analysis. Interestingly, the elemental peaks showed a rightward shift post-irradiation, suggesting crystalline changes like those seen in ordinary concrete.

In XRD analysis, the peak area directly correlates with the amount of crystalline element present ⁹⁶. The peak area remained consistent in size for all concrete samples, both before and after irradiation, while the peak height or intensity counts changed following irradiation. For ordinary concrete grade 15, the intensity counts of quartz, bismuth, and albite peaks increased after 24 hours of irradiation. In contrast, barite concrete in grades 25 and 35 exhibited the highest peak intensity. The broadening of diffraction peaks is more significant for smaller particles, leading to reduced peak height intensity, which may contribute to the observed variations ⁹⁷. A comparative analysis of quartz standards for bulk sample analysis could offer further insights.

The peak shifting towards the right side in XRD analysis can be attributed to the contraction of the crystal lattice ⁹⁸. This contraction may result from factors such as lattice compression, structural changes, or lattice distortions induced by external influences like irradiation or thermal treatments ⁹⁹. Additionally, strained lattice can cause right peak shifts, indicating a decrease in interplanar spacing between lattice planes and a more compact arrangement of atoms within the lattice. Variations in lattice spacing due to factors like strain or composition changes can lead to peak shifts⁹⁹ .

During irradiation, minerals may undergo expansion due to local stiffness and expansion heterogeneities, resulting in the formation of defects such as cracks, additional porosity, or radiation-induced volumetric expansion (RIVE) ^47,100. Increased surface stresses from treatments can also influence diffraction patterns, causing peak shifts towards higher angles. Radiation exposure in ordinary concrete can disrupt the atomic scale of silica, leading to amorphization and metamictization of structures, causing volume expansion, especially in quartz ^21,104 The irradiation-induced change in minerals' elastic constants can affect the Young's modulus of aggregates, particularly those with a high silica content ¹⁰³. The irradiation-induced change in the minerals' elastic constants contributes to the Young's modulus of aggregates with a silica content of over 65%. However, as the silica content decreases, the rate of Young's modulus loss with the amorphization index becomes less sharp. For aggregates with silica content ranging from 20–65%, the changing elastic properties of irradiated minerals may interact with RIVE-induced mismatch strains, leading to damage and contributing to the effective loss of stiffness in the aggregates ^103,105

Peak shifting often occurs following annealing treatments and exposure to high temperatures before experimentation. Heating Zr-Sn-Nb-Fe alloys to 750°C for two hours did not result in perfect grain growth due to the pinning effect of precipitates ¹⁰⁶. Annealing at different temperatures can promote precipitation, randomization of crystals, or the growth of equiaxed grains. Mechanically exfoliated (ME) treatment of SnO₂ thin films can cause peaks to shift towards larger diffraction angles, enhancing the visibility of the crystal phase ¹⁰⁷. Studies on graphite have shown that XRD (001) peaks tend to shift towards lower angles as temperature increases, while other characteristic peaks remain stable ¹⁰¹. Simulating defective graphite can isolate the impact of irradiation on XRD patterns, revealing the effects of interstitial or vacancy defects. The microstructure significantly influences XRD patterns, with single crystal structures with defects showing shifts in XRD peaks that can be explained by a simple layer expansion model.

Lattice Parameters

The lattice parameter is the distance between the atoms in a crystal lattice as discussed, lattice parameter changes have become the main contribution factors for peak shifting ⁶². Changes in the lattice parameter can indicate alterations in the crystal structure due to factors such as hydration, temperature, particle size, or irradiation ¹⁰¹. When the lattice parameter increases, the distance between the atoms in the crystal lattice also increases, while a decrease in the lattice parameter results in a decrease in the distance between the atoms in the crystal lattice ⁶¹. The lattice parameter can be affected by external factors such as pressure, temperature, and the presence of impurities. In some cases, the lattice parameter can also be affected by the size of the particles, with smaller particles exhibiting a decrease in the lattice parameter due to the surface energy effects. The lattice parameter is an important parameter in the study of crystal structures and can provide valuable insights into the properties of materials. Studying these changes is valuable for understanding the performance and durability of concrete over time, especially in applications where radiation exposure is a concern, such as nuclear facilities.

Meanwhile, the d-value (interplanar spacing or distance between adjacent lattice planes) is a crucial parameter that provides information about the crystal structure of the material ¹⁰⁸. The significance of the d-value in crystallography and X-ray diffraction analysis cannot be overstated. Also known as d-spacing, this value represents the spacing between successive crystal lattice planes within a material, serving as a cornerstone in determining the structural characteristics of a crystal⁹⁹. The d-value directly correlates with the unit cell parameters and orientation of crystal lattice planes, providing vital insights into the arrangement of atoms within the crystal lattice. By measuring the d-values of diffraction peaks in XRD patterns, researchers can extrapolate crucial information regarding atomic spacing, symmetry, and crystalline orientation⁹⁹. Thus, the relationship between the d-value and crystal structure serves as a linchpin for comprehending the internal arrangement of atoms in crystalline materials. It stands as a pivotal parameter in X-ray diffraction analysis, facilitating the accurate characterization of crystal structures.

For this experiment, The calculation of d- value in materials was calculated based on index miller (hkl) obtained from XRD as presented in the Table below Using the XRD d value calculator or InstaNANO¹⁰⁹.

Table 7

The difference of distance between adjacent lattice parameters before and after irradiation for ordinary concrete.
Grade of concrete	Index miller (hkl)	d-value (distance between adjacent lattice planes) (Å)				Different of d value
Grade of concrete	Index miller (hkl)	Before	After 24 hours	After 48 hours	After 72 hours	After 24 hours	After 48 hours	After 72 hours
OC 15	100	4.26	4.26	4.26	4.23	0.00	0.00	-0.03
	011	3.35	3.35	3.35	3.31	0.00	0.00	-0.03
	110	3.25	3.24	3.25	3.21	-0.01	+ 0.02	-0.02
OC 25	100	4.26	4.22	4.16	4.20	-0.04	-0.10	-0.06
	011	3.34	3.31	3.31	3.31	-0.03	-0.03	-0.03
	110	3.24	3.20	3.15	3.21	-0.04	-0.09	-0.03
OC 35	100	4.29	4.25	4.24	4.25	-0.04	-0.05	-0.04
	011	3.37	3.34	3.33	3.33	-0.03	-0.04	-0.04
	110	3.28	3.25	3.24	3.24	-0.03	-0.04	-0.04
OC 45	100	4.24	4.26	4.25	4.23	+ 0.02	+ 0.01	-0.01
	011	3.39	3.35	3.34	3.33	-0.04	-0.05	-0.06
	110	3.26	3.25	3.24	3.25	-0.01	-0.02	-0.01

(-) = decrement (+) = increment * All units in Angstrom (10^− 8)

Table 8

The different of the distance between adjacent lattice parameters before and after irradiation for ordinary concrete.
Grade of concrete	Index miller (hkl)	d-value (distance between adjacent lattice planes) (Å)				Different of d value
Grade of concrete	Index miller (hkl)	Before irradiation	After 24 hours	After 48 hours	After 72 hours	After 24 hours	After 48 hours	After 72 hours
BC 15	111	3.58	3.54	3.54	3.53	-0.04	-0.04	-0.05
	021	3.45	3.41	3.40	3.40	-0.04	-0.05	-0.05
	210	3.32	3.28	3.28	3.28	-0.04	-0.04	-0.04
	121	3.11	3.07	3.07	3.06	-0.04	-0.04	-0.05
BC 25	111	3.61	3.58	3.58	3.58	-0.03	-0.03	-0.03
	021	3.48	3.45	3.44	3.44	-0.03	-0.04	-0.04
	210	3.36	3.32	3.32	3.32	-0.04	-0.04	-0.04
	121	3.14	3.10	3.10	3.10	-0.04	-0.04	-0.04
BC 35	111	3.58	3.54	3.53	3.53	-0.04	-0.05	-0.05
	021	3.44	3.40	3.39	3.39	-0.04	-0.05	-0.05
	210	3.32	3.28	3.27	2.27	-0.04	-0.05	-0.05
	121	3.11	3.07	3.06	3.06	-0.04	-0.05	-0.05
BC 45	111	3.63	3.58	3.58	3.58	-0.05	-0.05	-0.05
	021	3.49	3.44	3.44	3.44	-0.05	-0.05	-0.05
	210	3.36	3.32	3.32	3.32	-0.04	-0.04	-0.04
	121	3.14	3.10	3.10	3.10	-0.04	-0.04	-0.04

(-) = decrement (+) = increment * All unit in Angstrom (10^− 8)

From the tabulated data, it is evident that the Miller indices in ordinary concrete and barite concrete remain consistent across all grades, characterized by 100, 011, and 110 for ordinary concrete and 111, 021, 210, and 121 for barite concrete. For ordinary concrete, there is an increment in the d spacing value instead of a decrement as in barite concrete. For grade 15, there is no observable change in the Miller index 100 during the initial 24- and 48-hours post-irradiation. However, a marginal reduction of 0.03 Å in the d value is noted after 72 hours of irradiation.

Compared with ordinary concrete, barite concrete showed a reduction in decrement in d-value difference post-irradiation. the decrement is seen in the XRD peak of concrete as the gap of peak shifting is huge compared to ordinary concrete. the decrement is in consistent value between 0.03 Å to 0.05 Å. The term 'decrement in d-spacing' denotes a reduction in the interplanar spacing between crystal lattice planes. In XRD analysis, d-spacing represents the distance between adjacent crystal lattice planes within a material. A decrease in d-spacing indicates a reduction in the distance between these planes, potentially caused by lattice compression, structural modifications, or lattice distortions induced by external factors such as irradiation or thermal treatments. Observing a decrement in d-spacing during XRD analysis suggests a contraction in the crystal lattice structure, resulting in a shorter distance between atomic planes. This reduction offers valuable insights into atomic-level changes within the material, reflecting alterations in the crystal structure, formation of defects, or phase transformations that lead to a more densely packed arrangement of atoms within the lattice⁹⁹.

In crystallography, the d-value holds an inverse relationship with the interplanar spacing of crystal lattice planes. A smaller d-value indicates a shorter distance between adjacent lattice planes, suggesting a more densely packed crystal structure. Conversely, a larger d-value denotes a greater distance between lattice planes, indicative of a more open or less dense crystal structure ¹¹⁰

Crystallite size

The primary objective of employing XRD is to analyze alterations in crystal size induced by irradiation over a given timeframe. Evaluating the size of these crystal structures is crucial for understanding the expansion and contraction phenomena experienced by elemental particles within concrete materials. The observed shift in XRD peaks serves as evidence for the expansion of crystals within the aggregate during irradiation ¹⁰⁷. A comprehensive analysis of the data presented in Figs. 12 and 13 leads to the conclusion that irradiation induces a change in the crystalline size of ordinary concrete, manifesting as an expansion from its original dimensions before exposure to irradiation.

Figure 12: The changes of crystal size of ordinary concrete before and after irradiation.

Figure 13: The changes of crystal size of barite concrete before and after irradiation.

Based on the above Figs. 12, irradiation has increased the size of crystal in concrete. For ordinary concrete, the initial average crystal size ranges between 600 to 700 nm before irradiation. Following irradiation, a notable increase in crystal size occurs, but it does not surpass 1000 nm. Grade 15 concrete exhibits the largest average crystal size, reaching 921.7 nm after 24 hours of irradiation, representing a significant increment of over 49%. Grade 45 boasts the largest crystal size before irradiation, exceeding 700 nm. Post-irradiation, the crystal size continues to increase, reaching up to 800 nm but remaining below 900 nm, representing a 25% increment after 72 hours of irradiation. Meanwhile, for barite concrete, the average size of crystalline particles before irradiation ranged from 500 nm to 700 nm. Like ordinary concrete, the average crystalline size increased after 24 and 48 hours of irradiation but decreased after 72 hours. However, the expansion did not exceed 1000 nm, with the highest expansion observed in BC 35 after 24 hours of irradiation, reaching more than 900 nm. Nevertheless, the decrease in crystalline size still represented an increase from the original size. The most significant expansion occurred in BC 25 after 48 hours of irradiation, with an expansion of more than 300 nm, accounting for over 62%.

Researchers have identified reasons behind the expansion of crystalline size in the microstructure of concrete after irradiation. Radiation fields that directly affect shielding materials are typically characterized by gamma-ray dose and neutron fluence^48,49. Based on the findings, neutron irradiation of crystalline materials leads to swelling, attributed to the formation of an equal number of interstitials and vacancies ¹⁰². In a reactor environment, when neutrons collide with atoms, some kinetic energy is transferred to the target atom, resulting in changes to the atomic structure. This collision leads to the formation of a Frenkel pair, where an atom is displaced from its initial position, leaving behind a void^86,111. The displaced atom becomes interstitial once it settles in one of the lattice sites. The irradiation effect and the primary source of damage to the microscopic structure of materials stem from this vacancy–interstitial pair, commonly known as the Frenkel pair ^111,112. As a result of irradiation exposure, minerals may change their atomic structures, consequently altering their physical and chemical properties ^113,114. This irradiation-induced swelling results in alterations to both the macroscopic length and lattice parameter of the material¹⁰².

It has been reported that quartz possesses the highest potential for radiation-induced volumetric expansion (RIVE) compared to other aggregates ^48,115–117. Quartz, normally composed of SiO₂, is commonly used in ordinary concrete aggregates, such as silica sand or other silicate glass ¹¹⁸. Previous studies have been conducted to investigate the damage inflicted on quartz by various forms of radiation, including neutrons and other ions ^117,119,120. Khmurovska et al. ¹²¹ concluded that aggregates commonly used in ordinary concrete are not suitable for application in irradiated concrete because of their high potential for RIVE. The volumetric expansion of hydrated cement paste induced by irradiation and its impact on the microstructure of aggregates has been extensively discussed in a study by Pape ¹²². According to him, aggregates containing quartz in high proportions (around 90%) can exhibit significant expansions of up to 18%. Similarly, for aggregates with a lower quartz content (around 50%), the expansion may reach up to 6.6% ¹¹⁷. Moreover, the expansion of quartz amorphous aggregates can be as high as 17.8% ¹⁰³, depending on the volume content of quartz present in the aggregate.

Notably, the degradation caused by neutron irradiation tends to be more pronounced compared to gamma rays because neutrons are inherently more aggressive. This aggressiveness is particularly evident in solid materials compared to liquids, due to the higher density of aggregates to cement paste. Furthermore, this phenomenon sheds light on the observation that materials such as barite exhibit higher expansion volumes compared to ordinary aggregates. The difference is attributed to the higher density of barite aggregates compared to limestone, highlighting the impact of aggregate density on the degree of expansion caused by irradiation¹²³.

An effective radiation shield should have the ability to attenuate, absorb, or obstruct a significant portion of incoming gamma radiation. Understanding the nature and mechanisms of interaction between gamma rays and materials is essential for evaluating their effectiveness in dispersing and containing radiation within a medium. This knowledge helps in selecting the most appropriate radiation shield based on the predominant mechanism of interaction. In this experimental investigation, the efficacy of ordinary concrete and barite as shielding materials against gamma rays and neutrons was explored, with a focus on analyzing post-irradiation changes in their crystalline structures. Concrete grades 15, 25, 35, and 45 underwent irradiation tests for neutron irradiation durations of 24, 42, and 72 hours in a thermal column. The tests used limestone and barite as the aggregate materials.

The study revealed that ordinary concrete had a density below 2.5 g/cm³ and compression strengths of up to 44 MPa, whereas barite concrete had densities exceeding 3.0 g/cm³ but compression strengths below 40 MPa. The findings revealed that ordinary concrete grade 35 displayed the highest linear attenuation coefficient, measuring 0.195 cm⁻¹ for ⁶⁰Co and 0.292 cm⁻¹ for ¹³⁷Cs. However, in comparison with other research on barite concrete, which exhibited a density below 3.0 g/cm³, the linear attenuation coefficient was lower than 0.2 cm⁻¹. Increasing a material's density is crucial for enhancing its effectiveness in radiation shielding, as indicated by the higher linear attenuation coefficient. Notably, ordinary concrete demonstrated superior protection against 137Cs compared to 60Co, with lead equivalents ranging from 3.6 to 4.2 mm for 60Co and 5.0 to 5.4 mm for 137Cs, highlighting its shielding efficacy against radiation.

The XRD results revealed significant changes in lattice parameters, with all peaks shifting to the right after 24, 48, and 72 hours of irradiation. This shift indicates an increase in crystallite size, which was particularly notable after irradiation, resulting in an expansion of the crystallite size. Furthermore, the d-spacing, or inter-atomic spacing, exhibited both decremental and incremental changes due to irradiation, although they were not significant. In summary, neutron exposure induced alterations in crystal size and inter-atomic distances, albeit minor, while maintaining the concrete's core functions and properties as a shielding material. While ordinary concrete may experience a greater impact from irradiation compared to barite concrete, it remains effective for shielding against low-dose irradiation, thus holding significance for applications involving lower-dose radiation scenarios.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Author Contribution

Nasuha ahmad : contribution of idea, the conceptualization of experimental design, conducting the experimental, data analysis, manuscript writing, and review.Mohd Idzat Idris : Contribution of ideas, the conceptualization of experimental design, data analysis, and manuscript reviewAzimah Hussin: Contribution of idea, conceptualization of experimental design, manuscript reviewJulia Abdul Karim: conceptualization of experimental design, conduct the experimental and manuscript review.Azreen Mansenwat: conceptualization of experimental design, conduct the experimental and manuscript review.Rafidah Zainon- conceptualization of writing and manuscript review.

Acknowledgement

The authors extend their sincere appreciation to Universiti Kebangsaan Malaysia and the Malaysian Nuclear Agency for their collaboration and support in this research endeavours. Gratitude is also extended to other research institutes involved in this project. Funding for this research was provided through the University Research Grant (GUP2022-046).

Data Availability

Data sets generated during the current study are available from the corresponding author on reasonable request. The datasets generated and analysed during the current study are not publicly anywhere else. However, data supporting the findings of this study are available from the corresponding author upon reasonable request.

He, W., Feng, Z. & Chen, L. Research on biological sealing for openings in nuclear power plant Resea. earth Environ. Sci. 675, 012097 (2021).
Ouda, A. S. & Abdelgader, H. S. Assessing the Physical, Mechanical Properties, and Γ-Ray Attenuation of Heavy Density Concrete for Radiation Shielding Purposes. Geosystem Eng. 22, 72–80 (2019).
Mortazavi, S. M. J. & Raadpey, N. High-Performance Heavy Concrete as a Multi-Pupose Shield. Radiat. Prot. Dosim. Dosim. 142, 120–124 (2010).
Khalaf, M. A. et al. Physicomechanical and Gamma-Ray Shielding Properties of High-Strength Heavyweight Concrete Containing Steel Furnace Slag Aggregate. J. Build. Eng. 30, 101306 (2020).
Y. Elmahroug, B. T. & C. S. Calculation of Gamma and Neutron Shielding Parameters for Some Materials Polyethylene-Based. Int. J. Phys. Res. 3, 33–40 (2013).
Ouda, A. S. Development of High-Performance Heavy Density Concrete Using Different Aggregates for Gamma-Ray Shielding. Prog. Nucl. Energy 79, 48–55 (2015).
C, B. P., Pierre, L. & J, N. D. Nuclear Power Plant Concrete Structures. in 22nd Conference on Structural Mechanics in Reactor Technology (2013).
Reisz, J. A., Bansal, N., Qian, J., Zhao, W. & Furdui, C. M. Effects of Ionizing Radiation on Biological Molecules - Mechanisms of Damage and Emerging Methods of Detection. Antioxidants Redox Signal. 21, 260–292 (2014).
Rasoul Abdar Esfahani, S. M. et al. Mechanical and Gamma-Ray Shielding Properties and Environmental Benefits of Concrete Incorporating GGBFS and Copper Slag. J. Build. Eng. 33, 101615 (2021).
Kawai, M. & Takashi, K. Development of Neutron Shielding Concrete Containing Colemanite and Peridotite. in Proceedings of the 14th International Workshop on Spallation Materials Technology (2020). doi:10.7566/JPSCP.28.081007.
Azreen, N. M., Rashid, R. S. M., Haniza, M., Voo, Y. L. & Mugahed Amran, Y. H. Radiation shielding of Ultra-High-Performance Concrete With Silica Sand, Amang and Lead Glass. Constr. Build. Mater. 172, 370–377 (2018).
Khalaf, M. A. et al. Physicomechanical and Gamma-Ray Shielding Properties of High-Strength Heavyweight Concrete Containing Steel Furnace Slag Aggregate. J. Build. Eng. 30, (2020).
Ouda, A. S. Development of high-performance heavy density concrete using different aggregates for gamma-ray shielding. HBRC J. 11, 328–338 (2015).
Kansouh, W. A. Radiation Distribution Through Serpentine Concrete Using Local Materials and Its Application as a Reactor Biological Shield. Ann. Nucl. Energy 47, 258–263 (2012).
Ho, M., Obbard, E., Burr, P. A. & Yeoh, G. A Review On The Development Of Nuclear Power Reactors. Energy Procedia 160, 459–466 (2019).
Terrani, K. A. et al. Fabrication and characterization of fully ceramic microencapsulated fuels. J. Nucl. Mater. 426, 268–276 (2012).
Rasheed, P. A., Nayar, S. K., Barsoum, I. & Alfantazi, A. Degradation of Concrete Structures in Nuclear Power Plants: A Review of the Major Causes and Possible Preventive Measures. Energies 15, 3–24 (2022).
Bruck, P. M., Esselman, T. C., Elaidi, B. M., Wall, J. J. & Wong, E. L. Structural Assessment of Radiation Damage in Light Water Power Reactor Concrete Biological Shield Walls. Nucl. Eng. Des. 350, 9–20 (2019).
Tyagi, G., Singhal, A., Routroy, S., Bhunia, D. & Lahoti, M. Radiation Shielding Concrete With Alternate Constituents: An Approach to Address Multiple Hazards. J. Hazard. Mater. 404, 124201 (2021).
Sims, I., Lay, J. & Ferrari, J. I. Concrete aggregates. Lea’s Chemistry of Cement and Concrete (Elsevier Ltd., 2019). doi:10.1016/B978-0-08-100773-0.00015-0.
Krishnan, N. M. A., Le Pape, Y., Sant, G. & Bauchy, M. Effect of Irradiation on Silicate Aggregates’ Density And Stiffness. J. Nucl. Mater. 512, 126–136 (2018).
Ahmed, G. H., Ahmed, H., Ali, B. & Alyousef, R. Assessment of High Performance Self-Consolidating Concrete Through an Experimental and Analytical Multi-Parameter Approach. Materials (Basel). 14, 1–22 (2021).
Kaplan, M. f. Concrete Radiation Shielding: Nuclear Physics, Concrete Properties, Design and Construction. (Harlow, Essex, England: Longman Scientific & Technical ; New York : Wiley, 1989., 1989).
Çullu, M. & Ertaş, H. Determination of the Effect of Lead Mine Waste Aggregate On Some Concrete Properties and Radiation Shielding. Constr. Build. Mater. 125, 625–631 (2016).
Mortazavi, S. M. J. et al. Production of an Economic High-Density Concrete for Shielding Megavoltage Radiotherapy Rooms and Nuclear Reactors. Iran. J. Radiat. Res. 5, 143–146 (2007).
Shi, C. et al. Performance Enhancement of Recycled Concrete Aggregate - A review. J. Clean. Prod. 112, 466–472 (2016).
Zagar, T. & Ravnik, M. Measurement of Neutron Activation in Concrete. in International Conference of Nuclear Energy in Central Europe – 2000 1–8 (2000).
Akkurt, I. et al. Determination of Some Heavyweight Aggregate Half Value Layer Thickness Used for Radiation Shielding. Acta Phys. Pol. A 121, 138–140 (2012).
Northup, T. High-Density Concrete for Gamma and Neutron Attenuation. Trans. Am. Nucl. Soc. Vol: 8, (1965).
Gallego, E., Lorente, A. & Vega-carrillo, H. R. Testing of A High-Density Concrete as Neutron. (2009) doi:10.13182/NT09-A9216.
Józwiak-Niedzwiedzka, D., Glinicki, M. A. & Gibas, K. Potential For Alkali-Silica Reaction in Radiation Shielding Concrete Containing Special Aggregates. in International Conference on Durability of Concrete Structures, ICDCS 2016 230–235 (2016). doi:10.5703/1288284316137.
Bashter, I. I. Calculation of radiation attenuation coefficients for shielding concretes. Ann. Nucl. Energy 24, 1389–1401 (1997).
Abdullah, M. A. H. et al. Recent Trends in Advanced Radiation Shielding Concrete for Construction of Facilities: Materials and Properties. Polymers (Basel). 14, (2022).
Kurtis, K. E. et al. Can We Design Concrete to Survive Nuclear Environments? Current Status of Concrete Nuclear Infrastructure. Concr. Int. 39, 29–35 (2017).
Basyigit, C. et al. Investigating Radiation Shielding Properties of Different Mineral Origin Heavyweight Concretes. AIP Conf. Proc. 1400, 232–235 (2011).
Kmita, A. A New Generation of Concrete in Civil Engineering. J. Mater. Process. Technol. 106, 80–86 (2000).
Lippiatt, B. C. & Ahmad, S. Measuring the Life-Cycle Environmental and Economic Performance of Concrete: the Bees Approach. in International Workshop on Sustainable Development and Concrete Technology 213–230 (2004).
Imam, A., Sharma, K. K., Kumar, V. & Singh, N. A Review Study on Sustainable Development of Ultra High-Performance Concrete. AIMS Mater. Sci. 9, 9–35 (2022).
Ahmad, I. et al. Densification of Concrete Using Barite as Fine Aggregate and Its Effect on Concrete Mechanical and Radiation Shielding Properties. J. Eng. Res. 7, 81–95 (2019).
Saidani, K., Ajam, L. & Ben Ouezdou, M. Barite Powder as Sand Substitution in Concrete: Effect On Some Mechanical Properties. Constr. Build. Mater. 95, 287–295 (2015).
Fu, X., Ji, Z., Lin, W., Yu, Y. & Wu, T. The Advancement of Neutron Shielding Materials for the Storage of Spent Nuclear Fuel. Sci. Technol. Nucl. Install. 2021, (2021).
Jóźwiak-Niedźwiedzka, D. & Lessing, P. A. High-Density and Radiation Shielding Concrete. in Developments in the Formulation and Reinforcement of Concrete 193–228 (2019). doi:10.1016/B978-0-08-102616-8.00009-5.
Tomaz Zagar, M. R. Activation of Triga Mark Ii Research Reactor Concrete Shield. in 1st World TRIGA User Conference 1–10 (2002).
Ghambhir, M. L. Fundamentals Of Reinforced Concrete Design. (PHI Learning Pvt. Ltd, 2006).
Ashwini, K. & Srinivasa Rao, P. Behavior of Concrete Using Alccofine and Nano-Silica Under Elevated Temperature. Int. J. Adv. Technol. Eng. Explor. 8, 600–618 (2021).
H.K.Hilsdorf, J. Kropp, and H. J. Koch. The Effects of Nuclear Radiation on the Mechanical Properties of Concrete. in Proceedings of the Douglas McHenry International Symposium on Concrete and Concrete Structures 223–251 (American Concrete Institute, 1978).
Zalegowski, K., Piotrowski, T., Garbacz, A. & Adamczewski, G. Relation Between Microstructure, Technical Properties and Neutron Radiation Shielding Efficiency of Concrete. Constr. Build. Mater. 235, 117389 (2020).
Field, K. G., Remec, I. & Pape, Y. Le. Radiation Effects in Concrete for Nuclear Power Plants - Part I: Quantification of Radiation Exposure and Radiation Effects. Nucl. Eng. Des. 282, 126–143 (2015).
Le Pape, Y., Field, K. G. & Remec, I. Radiation Effects in Concrete for Nuclear Power Plants, Part II: Perspective From Micromechanical Modeling. Nucl. Eng. Des. 282, 144–157 (2015).
Žagar, T., Božič, M. & Ravnik, M. Long-Lived Activation Products in TRIGA Mark II Research Reactor Concrete Shield: Calculation and Experiment. J. Nucl. Mater. 335, 379–386 (2004).
Iffat, S. Relation Between Density and Compressive Strength of Hardened Concrete. Concr. Res. Lett. 6, 182–189 (2015).
Rahim, M. A. et al. Relationship between Density and Early Compressive Strength of Slurry Infiltrated Fiber Reinforced Concrete (SIFCON). J. Phys. Conf. Ser. 2129, (2021).
Azreen, N. M. et al. Simulation of Ultra-High-Performance Concrete Mixed With Hematite and Barite Aggregates Using Monte Carlo For Dry Cask Storage. Constr. Build. Mater. 263, 120161 (2020).
Abualroos, N. J., Idris, M. I., Ibrahim, H., Kamaruzaman, M. I. & Zainon, R. Physical, Mechanical, and Microstructural Characterisation of Tungsten Carbide-Based Polymeric Composites for Radiation Shielding Application. Sci. Rep. 14, 1–17 (2024).
Oto, B., Gür, A., Kavaz, E., Çakır, T. & Yaltay, N. Determination of Gamma and Fast Neutron Shielding Parameters of Magnetite Concretes. Prog. Nucl. Energy 92, 71–80 (2016).
Akkaş, A. Determination of The Tenth and Half Value Layer Thickness Of Concretes With Different Densities. Acta Phys. Pol. A 129, 770–772 (2016).
Mollah, A. S. Evaluation of Gamma Radiation Attenuation Characteristics of Different Type Shielding Materials used in Nuclear Medicine Services. Bangladesh J. Nucl. Med. 21, 108–114 (2019).
El-Sawy, A. Influence of Different Natural Fiber-Based Composites Use As a Filler for Cracking in Nuclear Reactor Biological Shields. Eur. J. Mater. Sci. Eng. 6, 165–175 (2021).
Büermann, L. Determination of Lead Equivalent Values According to IEC 61331-1:2014 - Report and Short Guidelines for Testing Laboratories. J. Instrum. 11, (2016).
Liu, T. et al. Comparative Study of Mechanical Properties Between Irradiated and Regular Plastic Waste as a Replacement of Cement and Fine Aggregate for Manufacturing of Green Concrete. Ain Shams Eng. J. 13, 101563 (2022).
Jarin, S. et al. Predicting the Crystal Structure and Lattice Parameters of the Perovskite Materials via Different Machine Learning Models Based on Basic Atom Properties. Crystals 12, 1570 (2022).
Prasetya, A. D., Rifai, M., Mujamilah & Miyamoto, H. X-ray diffraction (XRD) Profile Analysis of Pure ECAP-annealing Nickel Samples. J. Phys. Conf. Ser. 1436, 012113 (2020).
Sagayaraj, R., Aravazhi, S. & Chandrasekaran, G. Microstructure and Magnetic Properties of Cu0.5Co0.3Mo0.2Fe2O4 Ferrite Nanoparticles Synthesized By Coprecipitation Method. Appl. Phys. A Mater. Sci. Process. 127, 1–8 (2021).
Sumadiyasa, M. & Manuaba, I. B. S. Penentuan Ukuran Kristal Menggunakan Formula Scherrer, Williamson-Hull Plot dan Ukuran Partikel dengan SEM. Bul. Fis. FMIPA UNUD, Buleti (No. 1) 19, 28–35 (2018).
Fapohunda, C., Akinbile, B. & Shittu, A. Structure and Properties of Mortar and Concrete With Rice Husk Ash as Partial Replacement of Ordinary Portland Cement – a Review. Int. J. Sustain. Built Environ. 6, 675–692 (2017).
Naus, D. J. Primer on Durability of Nuclear Power Plant Reinforced Concrete Structures - A Review of Pertinent Factors. Nureg/Cr-6927 Ornl/Tm-2006/529 https://info.ornl.gov/sites/publications/files/Pub2576.pdf (2007).
Murtafi’atin, R., Widarto, W., Susilo, S. & Made Dharma Putra, N. Analysis of Barite Concrete as a Potential Neutron Radiation Shielding Material for BNCT Facilities. ASEAN J. Sci. Technol. Dev. 36, 19–21 (2019).
Ramli, N. et al. Ageing Assessment of Biological Shielding Integrity for PUSPATI TRIGA Reactor. in IOP Conference Series: Materials Science and Engineering vol. 785 (2020).
Ikraiam, F. A., El-latif, A. A., Elazziz, A. A. & Ali, J. M. Effect of Steel Fiber Addition on Mechanical Properties and Γ-Ray Attenuation for Ordinary Concrete Used in El-Gabal El-Akhdar Area in Libya for Radiation Shielding Purposes. Arab J. Nucl. Sci. Appl 42, 287–295 (2009).
Li, Z. Structure Of Concrete. in Advanced Concrete Technology 140–163 (2011). doi:10.1002/9780470950067.ch4.
Xie, J. & Yan, J. B. Experimental Studies and Analysis on Compressive Strength of Normal-Weight Concrete at Low Temperatures. Struct. Concr. 19, 1235–1244 (2018).
Meddah, M. S., Zitouni, S. & Belâabes, S. Effect of Content and Particle Size Distribution of Coarse Aggregate on the Compressive Strength of Concrete. Constr. Build. Mater. 24, 505–512 (2010).
Sim, J. Il, Yang, K. H. & Jeon, J. K. Influence of Aggregate Size on The Compressive Size Effect According To Different Concrete Types. Constr. Build. Mater. 44, 716–725 (2013).
Ortiz, J., Aguado, A., Agulló, L. & García, T. Influence of Environmental Temperatures on The Concrete Compressive Strength: Simulation of Hot and Cold Weather Conditions. Cem. Concr. Res. 35, 1970–1979 (2005).
Gallala, W. et al. Mechanical and Radiation Shielding Properties of Mortars With Additive Fine Aggregate Mine Waste. Ann. Nucl. Energy 101, 600–606 (2017).
Sumarni, S. et al. Penggunaan Pasir Besi Dan Barit Sebagai Agregat Beton Berat Untuk Perisai Radiasi Sinar Gamma. Media Tek. Sipil 7, 93–100 (2009).
Sakr, K. et al. Utilization of Barite/Cement Composites for Gamma Rays Attenuation. Radiat. Eff. Defects Solids 173, 269–282 (2018).
Denisov, A. Radiation Changes in Serpentinite Concretes of Dry Radiation Shield in Nuclear Power Plants. IOP Conf. Ser. Mater. Sci. Eng. 365, (2018).
Denisov, A. Analytical Description of The Hydrogen Evolution From Concrete Under The Effect of Gamma Radiation. IOP Conf. Ser. Mater. Sci. Eng. 869, (2020).
Denisov, A. V. Radiation Changes of Concrete Aggregates Under The Influence of Gamma Radiation. Mag. Civ. Eng. 96, 94–109 (2020).
Horszczaruk, E., Sikora, P. & Zaporowski, P. Mechanical Properties of Shielding Concrete With Magnetite Aggregate Subjected To High Temperature. Procedia Eng. 108, 39–46 (2015).
Korolev, A. S. et al. Compressive and Tensile Elastic Properties of Concrete: Empirical Factors in Span Reinforced Structures Design. Materials (Basel). 14, 1–15 (2021).
Kaundal, R. S. Comparative Study of Radiation Shielding Parameters for Binary Oxide Glasses. Orient. J. Chem. 33, 2324–2328 (2017).
Azeez, M. O., Ahmad, S., Al-Dulaijan, S. U., Maslehuddin, M. & Abbas Naqvi, A. Radiation Shielding Performance Of Heavy-Weight Concrete Mixtures. Constr. Build. Mater. 224, 284–291 (2019).
Al-Humaiqani, M. M., Shuraim, A. B. & Hussain, R. R. γ -Radiation Shielding Properties of High Strength High-Performance Concretes Prepared with Different Types of Normal and Heavy Aggregates. Asian Trans. Eng. 03, 18–28 (2013).
Chen, S., Bernard, D. & De Saint Jean, C. Calculation and Analysis of Gamma-Induced Irradiation Damage Cross-Section. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 447, 8–21 (2019).
Khaldari, R., Mesbahi, A. & Kara, U. Monte Carlo Calculation of Shielding Properties of Newly Developed Heavy Concretes for Megavoltage Photon Beam Spectra Used in Radiation Therapy. Iran. J. Med. Phys. 13, 250–260 (2016).
Daungwilailuk, T. et al. Use of Barite Concrete for Radiation Shielding Against Gamma-Rays and Neutrons. Constr. Build. Mater. 326, 126838 (2022).
Przemyslaw Czapik. Microstructure and Degradation of Mortar Containing Waste Glass Aggregate as Evaluated by various microscopic techniques. Materials (Basel). 13, 25–30 (2020).
Kavaz, E. An Experimental Study on Gamma Ray Shielding Features of Lithium Borate Glasses Doped With Dolomite, Hematite and Goethite Minerals. Radiat. Phys. Chem. 160, 112–123 (2019).
Akkurt, I., Günoglu, K., Basyigit, C. & Akkas, A. Determination of Radiation Attenuation Coeffcients of Concretes in Different Densities. Acta Phys. Pol. A 123, 374–375 (2013).
Al-Ghamdi, H., Elsafi, M., Sayyed, M. I., Almuqrin, A. H. & Tamayo, P. Performance of Newly Developed Concretes Incorporating WO3 and Barite as Radiation Shielding Material. J. Mater. Res. Technol. 19, 4103–4114 (2022).
Kim, C. L., Jeong, H. C. & Kim, J. H. Radiation Shielding Effects of Lead Equivalent Thickness of A Radiation Protective Apron and Distance During C-Arm Fluoroscopy-Guided Pain Interventions: A Randomized Trial. Med. (United States) 102, E36447 (2023).
Singer, G., Wyckoff, H. O. & Day, F. H. Relative Thickness of Lead, Concrete, and Steel Required for Protection Against Narrow Beams of X-Rays. J. Res. Natl. Bur. Stand. (1934). 38, 665–672 (1947).
Fiskov, A. A., Magola, I. A., Ditts, A. A., Mitina, N. A. & Vinokurov, S. E. Impact of Temperature and Radiation Factors on Special Concretes Used for NPP Construction. J. Compos. Sci. 7, (2023).
Gao, Z., Dong, X., Li, N. & Ren, J. Novel Two-Dimensional Silicon Dioxide with in-Plane Negative Poisson’s Ratio. Nano Lett. 17, 772–777 (2017).
Khamis, F. & Arafah, D. Thermoluminescence Characteristics of Natural Quartz and Synthesized Silica Glass Prepared by Sol-Gel Technique. Asian J. Phys. Chem. Sci. 3, 1–16 (2017).
Chisholm, J. Comparison of quartz standards for X-ray diffraction analysis: HSE A9950 (Sikron F600) and NIST SRM 1878. Ann. Occup. Hyg. 49, 351–358 (2005).
Khan, H. et al. Experimental Methods in Chemical Engineering: X-Ray Diffraction Spectroscopy—XRD. Can. J. Chem. Eng. 98, 1255–1266 (2020).
Singh, D. K., Iyer, P. K. & Giri, P. K. Diameter Dependence Of Interwall Separation and Strain in Multiwalled Carbon Nanotubes Probed By X-Ray Diffraction and Raman Scattering Studies. Diam. Relat. Mater. 19, 1281–1288 (2010).
Phillips, R., Jolley, K., Zhou, Y. & Smith, R. Influence of Temperature and Point Defects on The X-Ray Diffraction Pattern Of Graphite. Carbon Trends 5, 100–124 (2021).
Idris, M. I., Konishi, H., Imai, M., Yoshida, K. & Yano, T. Neutron Irradiation Swelling of SiC and SiCf/SiC for Advanced Nuclear Applications. Energy Procedia 71, 328–336 (2015).
Le Pape, Y., Sanahuja, J. & Alsaid, M. H. F. Irradiation-Induced Damage in Concrete-Forming Aggregates: Revisiting Literature Data Through Micromechanics. Mater. Struct. 53, 53–62 (2020).
Le Pape, Y. Structural Effects of Radiation-Induced Volumetric Expansion on Unreinforced Concrete Biological Shields. Nucl. Eng. Des. 295, 534–548 (2015).
Primak, W. Fast-Neutron-Induced Changes in Quartz and Vitreous Silica. Phys. Rev. 110, 1240–1254 (1958).
Sugondo. The role of X-ray Diffraction for Analyzing Zr-Sn-Nb-Fe Alloys as Power Reactor Fuel Cladding. Atom Indones. 36, 77–85 (2010).
Abdillah, M. N., Sunu, W. & Dwandaru, B. XRD Peak Shift and Enhancement of Repeated Mechanically Exfoliated SnO 2 Thin Films Synthesized from SnCl 2 Powder by Direct Heating. Nanosci. Nanotechnol. Res. 4, 127–131 (2017).
Udhayan, S., Udayakumar, R., Sagayaraj, R. & Gurusamy, K. Evaluation of Bioactive Potential of a Tragia involucrata Healthy Leaf Extract @ ZnO Nanoparticles. Bionanoscience 11, 703–719 (2021).
XRD d value Calculator - InstaNANO. https://instanano.com/all/characterization/xrd/d-value/ (accessed March 19th, 2024).
Béchade, J. L., Menut, D., Doriot, S., Schlutig, S. & Sitaud, B. X-Ray Diffraction Analysis of Secondary Phases in Zirconium Alloys Before and After Neutron Irradiation At The MARS Synchrotron Radiation Beamline. J. Nucl. Mater. 437, 365–372 (2013).
Mascitti, J. A. & Madariaga, M. Method For The Calculation of DPA in The Reactor Pressure Vessel Of Atucha II. Sci. Technol. Nucl. Install. 2011, 1–6 (2011).
Nordlund, K. et al. Primary Radiation Damage: A Review of Current Understanding and Models. J. Nucl. Mater. 512, 450–479 (2018).
Agarwal, S., Lin, Y., Li, C., Stoller, R. E. & Zinkle, S. J. On the Use of SRIM for Calculating Vacancy Production: Quick Calculation and Full-Cascade Options. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 503, 11–29 (2021).
Chen, S., Bernard, D. & Blaise, P. Attenuation of Neutron and Photon-Induced Irradiation Damage in Pressurized Water Reactor Pressure Vessels. Ann. Nucl. Energy 145, 107601 (2020).
Pape, Y. Le, Alsaid, M. H. F. & Giorla, A. B. Rock-forming Minerals Radiation-Induced Volumetric Expansion - Revisiting Literature Data. J. Adv. Concr. Technol. 16, 191–209 (2018).
Giorla, A., Vaitová, M., Le Pape, Y. & Štemberk, P. Meso-Scale Modeling of Irradiated Concrete in Test Reactor. Nucl. Eng. Des. 295, 59–73 (2015).
Le Pape, Y., Giorla, A. & Sanahuja, J. Combined Effects of Temperature and Irradiation on Concrete Damage. J. Adv. Concr. Technol. 14, 70–86 (2016).
Wang, X., Zhang, Q., Li, X., Ye, J. & Li, L. Structural and Electronic Properties of Different Terminations For Quartz (001) Surfaces as Well as Water Molecule Adsorption On It: A First-Principles Study. Minerals 8, 1–16 (2018).
Wang, B., Yu, Y., Pignatelli, I., Sant, G. & Bauchy, M. Nature Of Radiation-Induced Defects in Quartz. J. Chem. Phys. 143, (2015).
Petrounias, P. et al. Petrographic and Mechanical Characteristics of Concrete Produced by Different Type of Recycled Materials. Geosci. 9, (2019).
Khmurovska, Y. & Štemberk, P. Numerical Estimation of Radiation Induced Volumetric Expansion of Igneous Rocks. Spec. Concr. Compos. 2020 2322, 020032 (2021).
Le Pape, Y. Structural Effects of Radiation-Induced Volumetric Expansion On Unreinforced Concrete Biological Shields. Nucl. Eng. Des. 295, 534–548 (2015).
Maruyama, I. et al. Development of Soundness Assessment Procedure for Concrete Members Affected by Neutron and Gamma-Ray Irradiation. J. Adv. Concr. Technol. 15, 440–523 (2017).

No competing interests reported.

Download PDF

Journal Publication

published 29 Oct, 2024

Read the published version in Scientific Reports →

Editorial decision: Revision requested
12 Jun, 2024
Reviews received at journal
10 Jun, 2024
Reviewers agreed at journal
10 Jun, 2024
Reviews received at journal
31 May, 2024
Reviewers agreed at journal
22 May, 2024
Reviewers agreed at journal
21 May, 2024
Reviewers invited by journal
20 May, 2024
Editor assigned by journal
20 May, 2024
Editor invited by journal
18 May, 2024
Submission checks completed at journal
17 May, 2024
First submitted to journal
06 May, 2024

You are reading this latest preprint version

Enhancing Shielding Efficiency of Ordinary and Barite Concrete in Radiation Shielding Utilizations

Status:

Journal Publication

Version 1

Abstract

Figures

1.0 Introduction

2.0 Methodology of Experiment

2.1 Fabrication of Ordinary Concrete and Barite Concrete

2.2 Pre-radiation Test

2.2 Neutron irradiation

4.0 Result and Discussion

4.1 Physical Properties of Concrete

3.2 Radiation Attenuation Test

1.0 Neutron Irradiation Test

3.2.1 XRD Result

Conclusion

Declarations

Declaration of Competing Interest

Author Contribution

Acknowledgement

Data Availability

References

Additional Declarations

Status:

Journal Publication

Version 1