Study on Durability of Recycled Large Aggregate Concrete

Abstract

In this paper, natural large aggregate concrete (NAC) and recycled large aggregate concrete (RAC) are prepared. The impermeability, carbonation resistance, chloride ion penetration resistance, early crack resistance and dry shrinkage of the two kinds of concrete are compared and studied. The results show that, compared with NAC, when cured to the same age (28d), the water seepage height of RAC increased by 23.11%, and its relative permeability coefficient increased by 40.81%; carbonization depth increased by 14.63%; 6h chloride ion electric flux increased by 24.85%, chloride ion diffusion coefficient increased by 24.90%; the number of cracks per unit area increased by 68.88%, and the total crack area per unit area increased by 37.80%. The dry shrinkage rate increased by 50.46%. Although RAC's durability is worse than NAC, RAC prepared by reasonable technology has the same performance as NAC and can be used instead of NAC to some extent.