Cement is the primary ingredient in concrete, which is one of the crucial building materials. The evolution of greenhouse gases, particularly carbon dioxide, which is produced during the hydration stage, has increased because of excessive use of concrete. Geopolymer, an alumina-silicate based bonding substance is made up of waste materials such as Fly ash (FA) or Silica Fume (SF) in the presence of alkaline solutions has been developed to reduce the effect of carbon emissions on the environment. This paper studied the optimization and utilization of FA and SF replacement as pozzolanic materials for the development of sustainable geopolymer mortar and to achieve optimal mechanical strength using response surface methodology (RSM). According to the study, with the addition of 90% FA and 10% SF content to the geopolymer design mix significantly improves their mechanical properties. When SF and sodium hydroxide are combined to create geopolymer mortar, they work as an alkaline catalyst, dramatically reducing carbon emission of the waste materials and providing it an edge over cement-based mortar. The construction of self-sustaining infrastructures ensuring human safety and eco-friendly practices will be encouraged by the multi-objective approach of RSM.

Some brands of cement are often neglected in preference to others due to the fact that certain brands are more susceptible to cracks than others and also because of differences in their setting times. Continuous monitoring of these brands of cement prevents negative consequences for concrete structures. This research aimed at assessing the physical, chemical, and mineralogical composition of selected brands of Portland Limestone Cement (PLC) on strength performance in compliance with local and international standards. Tests such as specific gravity, standard consistency, setting time, soundness, fineness, compressive strength, chemical oxide compositions, and mineralogical properties were carried out to determine their suitability criteria for construction purposes, ensuring minimum established standards are met. The results indicated that at 28th day, Dangote PLC yielded the highest compressive strength of 48.02 kN/mm2 while UniCem PLC yielded the least compressive strength of 43.17 kN/mm2. The study concluded that the choice of cement strength class for any construction type interdepends on the physical, chemical, and mineralogical compositions of the cement incorporated at the place of use. Also, the margin difference in the strength and compositions of these cement brands does not give a significant reason to impede the performance. As such, none of these brands of PLC has a predominant advantage over the other, primarily for construction purposes. The knowledge of the properties of PLC in concrete construction is imperative to helping engineers make informed decisions about which brand is required to be used in specific circumstances for area of optimal applications.