keywords: Compressive strength, strength ratios, strength relations, splitting tensile strength
The results of splitting tensile strength and compressive strength ratios, as well the expression relating splitting tensile strength and compressive strength of concrete produced with Portland limestone cement are presented in this paper. Portland limestone cement grades 32.5R and 42.5R were used for this work. Concrete cube specimens 150 x 150 x 150 mm were used to measure the compressive strength while 150 x 300 mm cylindrical concrete specimens were used to assess the splitting tensile strength. Both strengths were measured at 7, 14, 21, 28, 60 and 90 days of curing. Experimental findings show that the 28-day ratios of the splitting tensile strength to the compressive strength for concrete produced with grade of cement 32.5 R are found to be higher than the specimens produced with grade 42.5R, both at the early and latter days. The results of analytical and experimental relationship indicate that the usual power expression, relating tensile to compressive strength, though popular in other brands of cement, may not be applicable to splitting tensile strength and compressive strength of concrete produced with all the grades of Portland limestone cement. The results show that logarithmic trend equation in the form ft = 2.3529ln(f_c) - 4.8642, with R2 values of 0.76 and above, because of its simplicity, is reliable in expressing the relationship between the splitting tensile strength and compressive strength of concrete produced with all the grades of Portland limestone cement.