Performance Influenced by Particle Size Distribution (PSD) of Composite Cement Incorporating Fly-Ash and Ground Granulated Blast Furnace Slag as SCMs

Over-mining of natural resources by the cement manufacturing industries to meet the demand–supply chain has led to erratic concretization across the planet earth. This in turn has adversely resulted in fast-growing resource depletion and human-made toxic gas release into the atmosphere. Also, the ginormous quantum of industrial wastes viz. fly-ash and slag, discharged by Thermal Power Plants (TPP), Steel Manufacturing Companies poses a dumping threat of polluting surface, and sub-surface water, and also the constraint of the limited disposal area. Extensive research is carried out to maximize the partial substitution of pure Ordinary Portland Cement (OPC) with Supplementary Cementitious Materials (SCMs). However, such replacement dwindles the overall performance of resultant cement and mainly a reduction in strength gain. It is obviously believed that the properties such as microstructure, packing density, chemical activation, the heat of hydration, water demand, sets, water absorption, permeability, workability, durability, and strength of any cement and its paste, mortar, and concrete are administered predominantly by the chemical composition of all pertinent raw materials and the average size was considered rather than the distribution of particle sizes in the given cement matrix. This paper articulates the performance influenced by the particle size distribution of Composite Cement comprising Ordinary Portland Cement (OPC), Stimulator (S), Fly-ash (FA), and Ground Granulated Blast Furnace Slag (GGBFS) trialed on certain key mechanical properties. The experimental results determined boosted strength gain at early as well as later curing ages with an improved physio-mechanical property of the resulting binder. This has further resulted in a drastic reduction in anthropogenic gas emissions. OPC with fly-ash and slag up to 60% combined substitution has taken the construction industry toward achieving its sustainability. Test results with modified PSD have shown an improvement in the high early strength when compared to conventional methods.