Abstract
The report presents the results of an experimental investigation on the compressive strength of concrete with particular reference on size and quantity of coarse aggregate. Several series of tests were carried out using single-size aggregate which are in narrow range of size. It is shown that the larger is pebble and the more aggregate is contained in concrete, the weaker is the concrete. When these relations are combined, the strength of one size aggregate concrete (glass marble or gravel) is expressed as a plane in a space co-ordinte, with different position according to the mortar strength which is mainly governed by water cement ratio. When the interface bond in ordinary concrete is the same with that of one size aggregate concrete, the compressive strength of the former can be expressed with the strength of each one size aggregate concrete and with each aggregate contents in present concrete. It is shown that the concrete has its own strength composition according to the quantity and the size of coarse aggregate.
