Investigation on Factors Influencing Workability of Recycled Aggregates Concrete

Abstract

In order to investigate factors influencing workability of recycled aggregates (RA) concrete, such as water amount, sand ratio and RA replacement percentage, 10 pitch of RA concrete was prepared for measurement of workability and a formula was used for calculating effect of water amount on slump of RA concrete. Experimental results and formula induction indicated that there are logarithmic relationship between flowability of fresh concrete and water amount and ratio of aggregates to cement . The flowability will logarithmically increase with increase of water amount and decrease of aggregates cement ratio. The optimum sand ratio for RA concrete can be determined by measurement of slump. Slump decreases with RA replacement percentage and there is a very good linear relationship between them. When water amount increases, slump increases and when replacement percentage of RA increases, slump decrease. Under different water amount, effect degrees of replacement percentage of RA on slump are very similar and under different replacement percentage of RA, effect degrees of water amount on slump are also very similar.