Portland Ordinary cement (OPC) and bricks are major building and construction materials worldwide . The annual global cement production (OPC) and bricks has reached approcimately 4 billion tonnes and 1391 billion units respectively [2, 3]. The demand is expected to continuously increase due to rapid worldwide growth of urban infrastructure development . Global cement production is estimated to increase from 4.83 billion metric tons by 2030 and grow by 45% in 2050 than the current production [5, 6]. Conventional bricks are produced from ordinary Portland cement (OPC), concrete or from clay with high temperature kiln firing . Manufacturing of OPC and clay fired bricks not only are energy intensive but releases enormous amounts CO2 and NOx responsible for global warming . To be specific, cement production industries around the world release greenhouse gases approximated to 1.5 billion tons each year into the atmosphere. Moreover, there is about 30 % of CO2 in the atmosphere . Moreover, the process of obtaining clay consumes vast amount of energy and generate large quantities of waste material that needs to be landfilled; the land for landfilling is reducing all over the world [9, 10]. Most of the developing countries have severe energy crisis causing power cuts and this puts more strain on the energy grid . To address challenges above-mentioned many researchers [12, 13, 14, 15, 16, 17, 18, 19 and 20]. have studied the reuse industrial waste such as; Fly ash, mine tailings, foundry sand, basic oxygen furnace slag, metakaolin and granulated furnace slag use of waste material to manufacture brick using geopolymerisation technology Geopolymers (GPs) are inorganic polymer products from the reaction between synthetic or natural aluminosilicate materials such as fly ash (FA) or metakaolinite and alkaline activators such as silicates, hydroxides of sodium and potassium at relatively low to nearly elevated temperatures [21, 22 and 23]. Although geopolymers are considered as radical materials that have excellent characteristics such as high unconfined compressive strength, excellent fire resistance, low shrinkage, low liquid limit and energy efficient during production . Their environmental impact depends on the alkaline activating agents and the material used as precursors . Most of the studies conducted in geopolymerisation focused on the use of combination of silicates with either sodium or potassium hydroxide solution to produce geopolymer bricks or binder. However, feasibility studies of using a single alkaline activator to produce a geopolymer binder and evaluate its binding properties by stabilizing other waste material to manufacture building bricks are scarce and limited. Temuujin et al. studied the geopolymerisation of GBFS using NaOH and NaSiO3 as alkaline activators which achieved UCS up to 70 MPa after 28 days of curing at ambient temperature . Mejia et al. developed geopolymeric binder by blending GBFS and fly ash and used sodium silicate Na2SiO3 as the alkaline activator, the UCS was around 30–40 MPa after 7 days of curing at ambient temperature. Mejia et al. further blended GBFS and metakaolinite, used silica reactive source and NaOH as activators, the resulting UCS was around 60 MPa after 28 days of curing . Robayo-Salazar et al. calcined a Colombian based NP and blended it with 30% GBFS, using combined alkaline activators NaOH and Na2SiO3, UCS results of the cement were up to 45 MPa after 28 days or curing at ambient temperature . Rashad et. al. proved that alkaline activating Metakaolin with Na2SiO3 and NaOH, after 28 days of curing at ambient temperature, UCS results of the binder activated with NaOH was only 27 MPa whereas that activated with Na2SiO3 was as high as 170 MPa . Falah et al. reported that using aqueous Na2SiO3 instead of NaOH improves geopolymerisation and the mechanical strength of geopolymeric binder . Even though NaSiO3 favors the geopolymerisation and offers excellent mechanical strength, silicates (in either liquid or solid form) have highest negative environmental but produced the binder with good mechanical strength . Tekin et al.  reported that sodium hydroxide (NaOH) is more eco-friendly solution than sodium metasilicate (NaSiO3) in terms of CO2 emission. Hence, Sithole et al. studied the feasibility of using a single alkaline activator NaOH to successfully develop GBFS-based geopolymer binder that achieved unconfined compressive strength of 72 MPa at elevated temperatures . Sithole et al study demonstrated that the synthesised geopolymer specimen is environmentally friendly and complies with American Society for Testing Materials (ASTM) C34-13, C129-14a and South African standard (SANS227: 2007). However, in most of the studies discussed above the UCS was used as a criterion to decide if the developed geopolymer can be classified as a binder; the binding properties of the developed geopolymers were not investigated. This research therefore seeks to address the above-mentioned challenges by using by-products granulated blast furnace slag to develop a binder that can replace OPC used in production of conventional bricks. Since river sand access is also becoming more costly and limited due to illegal dredging therefore waste foundry sand was used as an alternative raw material in production of building bricks and evaluating GBFS geopolymer binding properties . Waste foundry sand (WFS) is waste material which is produced about 0.6 tons per 1 ton of foundry industry production . While it cannot be recycled or reused, it will be disposed of in landfills. In addition, due to the fast dwindling of natural resource such as clay globally there is a need to preserve clay resource by exploring the reuse of waste as raw material in production both cementitious material and bricks. Re-use of wastes as raw materials not only conserves energy but it is also a commercially viable pollution control and a solution to a waste disposal problem . Industrial ecology (IE), a fast-growing discipline, advocates that the most efficient way to achieve sustainable development is via the imitation of the natural world . Therefore, re-use of by-products and waste products from anthropogenic processes is heavily supported to conserve the environment. This research therefore seeks also to achieve a zero waste discharge model by beneficiating of waste foundry sand by using it as a main raw material in production of bricks and use GBFS to develop a binder so that no waste is generated. About section numbering, the abstract is not included in section numbering. Subsection should be numbered 1.1. (then 1.1.1., 1.1.2., ...), 1.2., etc. Each heading should appear on its own separate line.