再生混凝土经历高温及冻融循环后抗压性能试验研究

Experimental study on compressive properties of recycled aggregate concrete after high temperature and freeze-thaw cycles

为研究再生混凝土经历高温及冻融循环后的抗压性能,以不同再生骨料取代率(0%、30%、50%、70%、100%)为主要变化参数,分析经历不同温度(20、200、400、600℃)及冻融循环(0、15次)作用后混凝土抗压强度的变化规律。研究结果表明:再生骨料取代率越大,混凝土抗冻融能力越差,取代率100%混凝土经高温和冻融作用后,其抗压强度仅为冻融前的60.7%;经历400℃高温及15次冻融循环作用后,再生骨料取代率超过50%时抗压强度明显下降,取代率100%混凝土的抗压强度仅为取代率0%时抗压强度的70.3%。

The concrete specimens with different recycled aggregate displacement ratios (0%, 30%, 50%, 70% and 100%) were manufactured. And the compressive strength of concrete specimens was tested after exposure to different temperatures (20, 200, 400 and 600) and different freeze-thaw cycles (0 and 15). The results show that the concrete specimens with higher recycled aggregate replacement ratio have worse freeze-thaw resistance. And the compressive strength of freeze-thaw concrete specimen with 100% replacement rate of recycled coarse aggregate has 60.7% of compressive strength of concrete specimens without freeze-thaw after high temperature. After 400 and then 15 freeze-thaw cycles, the compressive strength of concrete specimen is significantly decreased if the recycled aggregate displacement ratio is more than 50%. And the compressive strength of concrete specimen with 100% replacement rate of recycled coarse aggregate is 70.3% of compressive strength of ordinary concrete specimen. © 2016, Editorial Office of Journal of Building Structures. All right reserved.