Experimental evaluation of the effect of mix design ratios on compressive strength of cement mortars containing cement strength class 42.5 and 52.5 MPa

Cement mortar is one of the major cement-based construction materials and its mechanical properties perform an important role in the strength of structures. The effect of different mortar mix design parameters on its compressive strength has always been of great significance. Specifically, this research investigates the simultaneous effect of cement strength class and sand-cement (S/C) and water-cement ratios (W/C) on the compressive strength of mortars containing with cement strength class 42.5 and 52.5 MPa. For this purpose, an extensive experimental plan with 540 cubic 50 mm specimens made with 36 different mix designs. The results showed that the compressive strength of specimens increased with age and was strongly influenced by cement strength class, S/C and W/C ratio. The optimal mix design in terms of compressive strength is the with S/C ratio of 2.75, W/C ratio of 0.3, and cement strength class of 52.5 MPa.