再生粗骨料对破碎卵石混凝土抗压性能影响研究

为了研究再生粗骨料取代率对破碎卵石混凝土抗压性能的影响,和不同取代率下再生混凝土受压下的超声声速,制作了再生粗骨料取代率为0%、15%、30%、45%的标准立方体试块,进行龄期3、7、14、28、45 d的抗压性能试验,及28 d下的压应力-超声声速试验。研究结果表明:随着取代率的提高,各龄期下立方体抗压强度均呈先增长后降低趋势,其中3 d时该趋势尤为明显,当龄期超过28 d时该趋势变小。随着压应力系数的增加,各取代率下的超声声速均先增加后降低,当压应力系数为0. 2时取得最大值;对于同一压应力系数,随着取代率的提高,其超声声速的变化趋势与抗压强度的变化相似。

Influence of Recycled Coarse Aggregate on Compressive Property of Broken Pebble Concrete

In order to study the effect of the replacement rate of recycled coarse aggregate on the compressive property of broken pebble concrete and the supersonic velocity of compressed concrete under different replacement rates, the standard cube test blocks with the replacement rates of 0%, 15%, 30% and 45% of recycled coarse aggregate were prepared for compressive property tests on days 3, 7, 14, 28 and 45 and compressive stress-ultrasonic velocity tests on days 28. The results show that with the increase of the substitution rate, the compressive strength of the cubes in each age increases first and then decreases. The trend is especially obvious at 3 days, and the trend becomes smaller after the age of 28 days. With the increase of compressive stress coefficient, the ultrasonic sound velocity at each substitution rate increases first and then decreases. When the compressive stress coefficient is 0.2, the maximum value is obtained. For the same compressive stress coefficient, with the increase of substitution rate, the variation trend of ultrasonic velocity is similar to that of compressive strength.