Toward Green Concrete: Replacing Clinker with Trass materials to Produce Portland Pozzolan Cement

Trass is a pozzolanic additive from soft rock or soil layers derived from volcanic ash. This component can replace clinker in the manufacture of cement. The advantages of trass in cement manufacture are that it can regulate the reaction of calcium hydrate cement, increase chemical stability and improve mechanical properties. This study investigates the effect of adding trass to the quality of Portland pozzolan cement (PPC) in terms of compressive strength and setting time. In addition, it also observed the chemical and physical properties of cement. During the study, the substitution of trass on the clinker was in the range of 0-40% of the total mass. In addition, gypsum and limestone compositions were set at 3% and 5%, respectively. In other words, clinker was added at a variation of 52 to 86% (w/w). In this study, the fineness factor of the cement mixture was maintained in the range of 3800 – 4000 cm²/g. The effect of the contribution of trass on the cement mixture was measured by testing the chemical and physical properties, the compressive strength test of the mortar and the setting time test at the age of 1, 3, 7 and 28 days. The results showed that the addition of 21% trass significantly increased the mechanical properties of PPC at the age of 28 days, where the compressive strength was 371 kg/cm², the initial setting time was 190 min and the maximum final setting time was 290 min.