Synergistic Effects of Large-Sized Recycled Aggregates and High-Efficiency Water Reducer on the Performance of Concrete

This paper evaluates the effect of two kinds of recycled coarse aggregate with different sized particles on the performance of concrete.The test program is introduced, which investigated the compressive strength, axial compressive strength, the mass loss rate of concrete specimens after a freeze-thaw cycle and dynamic elasticity modulus change.The results show that the mechanical properties of the concrete decreased when it was prepared with recycled aggregate having the same size as that of the natural aggregates.The strength of the concrete with large-size recycled aggregate increased, and then decreased as the blend proportion rose above 50%.The strength of concrete incorporating oversized recycled aggregates exhibited a trend of rising and then falling with increasing mixing ratio.The 28-day compressive strength reached 45Mpa when the mixing amount was 50%.The durability of the large-size recycled aggregate was also found to improve compared with the freezing and thawing cycle experiments.These results provide a reference for research on the performance of recycled aggregate concrete.