Abstract
This study examined physical properties of lightweight aggregate concrete according to quality of structural artificial lightweight aggregates manufactured domestic and foreign. In the result, air contents of fresh concrete used lightweight aggregate was higher about 1~2 % than normal concrete and slump loss of fresh concrete in W/B 60 % was big. Compressive strength of lightweight concrete indicated lower than normal concrete, in particular which of these were low as the lower strength of lightweight aggregate. As the higher water absorption of aggregate, water absorption of concrete was high and dried unit volume weight of lightweight aggregate was 1.85~1.94 $t/m^3$, 0.4 $t/m^3$ higher than normal concrete used crushed aggregate. The static modulus of elasticity indicated that lightweight aggregate concrete decreased about $0.3{\sim}0.5{\times}10^4$ MPa compared to normal concrete. Drying shrinkage of lightweight aggregate concrete reduced, expecially it was prominent that as the bigger water absorption of lightweight aggregate and with continuous grading. Freeze-thaw resistance of lightweight aggregate concrete with W/B 40 % was satisfied with over 95 %, whereas it was reduced to under 90 % in W/B 60 % because pop-out by frost took place. Carbonation depth and chloride ion diffusion coefficient were on a par in comparison to normal concrete.
