温度对水泥基注浆体抗压强度影响的试验研究

    摘要：针对近年来不断出现的高地温注浆加固问题，在室内模拟相应工程环境，测试了不同养护温度（20、40、60和80 ℃）对不同水灰比和组成的水泥基注浆体抗压强度的影响。结果表明：浆体的抗压强度随水灰比增大而降低，水灰比较大时，降低幅度变缓；3 d抗压强度随温度的升高而提高，14 d和28 d抗压强度则在低于40 ℃时随温度升高而提高，高于40 ℃时随温度升高而降低；水灰比越小，有助于浆体强度发展的温度阈值越低；20 ℃和40 ℃养护时，浆体的抗压强度随龄期延长而提高，而养护温度为80 ℃时，抗压强度随龄期延长呈降低趋势。对于水灰比为1.0的浆体，在20 ℃和40 ℃养护时，掺入6%和9%的膨润土可以提高其抗压强度，而在80 ℃养护时，反而降低其抗压强度。

    关键词：水泥基注浆体；温度；水灰比；膨润土；抗压强度

    中图分类号：TU57+8.1        文献标识码：A        文章编号：1001-702X（2018）05-0067-04

 

Experimental studies of temperature effect on the compressive strength of solidified cement-based grout

FAN Lidan，SHI Zhijie，YU Yongqiang，LI Kaifang，ZHANG Zijian

（School of Civil Engineering，Henan Polytechnic University，Jiaozuo 454000，China）

   Abstract：In view of the recent emerging engineering of grouting reinforcement under high-temperature geothermal condition，the studies about the effect of temperature on compressive strength of solidified cement grout with different water-cement ratios and composition have been carried out in simulated environment in the laboratory. As a result of this study，the compressive strength significantly decline as the water-cement ratio increase，and it descends slowly when water-cement ratio goes up to a certain value． The 3 d strength presents a gradually increased tendency as the temperature rise，however，the 14 d and 28 d strength increases at temperature below 40 ℃ and then decreases at temperature above 40 ℃. The less the water-cement ratio is，the lower the corresponding temperature threshold beneficial for strength will be. Moreover，the strength improves with the growth of age at 20 ℃ and 40 ℃，whereas it presents a decreasing tendency at 80 ℃. The addition of 6% and 9% bentonite has favorable effect on the strength of cement grout with water-cement ratio of 1.0 at 20 ℃ and 40 ℃，nevertheless，it has negative effects at 80 ℃. 

    Key words：solidified cement-based grout，temperature，water-cement ratio，bentonite，compressive strength