The effect of aggregate volume on the properties of concrete.

This thesis describes an investigation into the effect of aggregate volume on the compressive strength, tensile strength and modulus of elasticity in both tension and compression of concrete. Emphasis has been placed on establishing the absorption properties of the aggregate and a relatively new technique of drying the aggregate in a stream of saturated air has been employed with satisfactory results. Also, a technique of strain measurement has been developed and was used to establish the values of the elastic modulus. In the strength investigation similar trends were observed in compression and in tension, the strength of cement paste being reduced on the addition of 20% of aggregate and increasing at aggregate volumes greater than 40% in tension and 60% in compression. The modulus increased, as expected, with the addition of aggregate and is predicted with reasonable accuracy by the simple lower bound solution from the method of mixtures