Influence of mix proportions and curing conditions on tensile splitting strength of high strength concretes

The effect of the composition of high strength concretes with low water to binder ratio and silica fume on the development of splitting tensile streng th was studied. A statistical approach was employed to develop formulation which could adequately describe the relations between splitting tensile str ength and the concrete composition, when cured in two different regimes: wa ter curing at 20 degrees C and sealed curing at 30 degrees C. Autogenous sh rinkage was induced in the second type of curing but was largely eliminated in the first one. The relations were presented as nomograms which could be used as a basis for mix design. The correlation between tensile splitting strength and compressive strength could not be described in terms of a simple linear relation with a charact eristic constant. For the range of variables studied, the ratio between ten sile and compressive strength varied over a large range of 0.08 to 0.12. As a result, the relations developed here for tensile strength are quite diff erent in nature than those for compressive strength in a previous study. An alysis of the data suggest that tensile strength is sensitive to effects wh ich induce autogenous shrinkage to a much greater extent than compressive s trength. It is proposed that this may be the main reason for the different trends observed for the relations between the composition of the low water/ binder ratio concretes and their compressive and tensile strength.