Microscopic Mechanism Study on Carbonation Resistance of Recycled Aggregate Concrete
24 100mm × 100mm × 300mm recycled concrete prisms and 96 150mm × 150mm × 150mm cubes are completed in this paper.The relationships of the carbonation depth in each carbonation age with replacement rate of recycled coarse aggregate and fly ash is studied; The SEM is used to observe the interface structure of recycled coarse aggregate concrete and compared with ordinary concrete, and finally,a recycled concrete carbonation model is proposed. The results showed that: the substitution of recycled coarse aggregate and fly ash cut down the recycled concrete carbonation resistance significantly, which are related with the replacement rate; the content of Ca(OH)2 in the recycled aggregate concrete decreased ,also there are obvious interface transition zone between the recycled coarse aggregate and the new cement;obvious cracks and large voids are exist before the recycled aggregate concrete is loaded, which lead directly to lower carbonation resistance of the recycled concrete.
Jianmin Zeng, Taosen Li, Shaojian Ma, Zhengyi Jiang and Daoguo Yang
H. F. Yang et al., "Microscopic Mechanism Study on Carbonation Resistance of Recycled Aggregate Concrete", Advanced Materials Research, Vols. 194-196, pp. 1001-1006, 2011