抄録
The water absorption of artificial lightweight aggregate in fresh concrete affects the compressive strength of concrete. The effect was investigated experimentally with particular reference on size, quantity and water content of the aggregate, using single sized coarse aggregate. The compressive strength of concrete with dry aggregate is higher than that of surface dry (wet) aggregate concrete when mix proportion is kept constant. The strength of both concrete show linear relationship with the cement water ratio respectively as long as they fail by bond failure of interface between coarse aggregate and cement paste. Herewith the effect of water absorption of aggregate can be regarded as the increase of cement water ratio of mortar for the concrete strength problem. Every aggregate of various size has its own value of the cement-water-ratio increase. The increase is about the same at any water cement ratio mix. The effect is proportional to the volume fraction of coarse aggregate and also is governed by the water content of aggregate. As for the ordinary mixe-sized lightweight aggregate, the increase of the concrete strength caused by the water absorption of aggregate can be obtained from the relationship on each factors above mentioned.
