Development of Green and Environmental Friendly Alternative Binder to Cement towards a Sustainable Construction

Portland Cement (PC) is currently the world most commonly used binder in mortar/concrete applications, PC-based concrete is the world’s most consumed man-made material and consequently puts lots of demand on cement as a binder. PC was later discovered to be non-environmental-friendly material due to its green house (carbon dioxide, CO2) gas emission mainly during production, which contributes greatly to global warming and all its negative impacts worldwide. Concrete production contributes up to 5% of the annual global CO2 emissions of which the bulk is from the production of cement. Other factor debilitating the use of PC is its high cost which further translates to the cost of mortar/concrete based structures as buildings, making housing less affordable for the citizenry. These PC concerns have led to the development of greener and cheaper alternative binders which have so far evolved the PC to blended and pozzolanic cements. This study is further evolving the binder to a fully pozzolanic process by combining a pozzolan sourced from NBRRI’s Pulverised Calcined Clay (PCC) with calcium hydroxide (Ca(OH)2) sourced from Carbide Waste (CW) which is the byproduct of carbide after being used to generate acetylene used in other industrial processes. This study have however shown that these two combinations in the presence of water can produce the C-S-H responsible for strength development as in cement hydration just that in this case, the CW meant for landfills and pozzolans which could also originate from Agro wastes can be used in the development of an alternative innovative binder to cement. This study tested the pozzolanic binder’s strength to BS 196-1:2005 and X-Ray Fluorescence (XRF) analysis and the results shows that this binder generated a 28-day curing strength of about 11MPa with the potential of generating higher later-day strength. This is about one-third the strength of a 32.5N/R cement grade. XRF analysis shows that the PCC in this study is a class N pozzolan with strength pozzolanic index of 129% and the CW purity level is about 70-80% Ca(OH)2. Commercializing this study outcome can result to the use of cheaper and more sustainable construction than the most currently used binder, cement