改性超细水泥浆液物理力学性能试验研究

Experimental Study on the Physical and Mechanical Properties of Modified Ultra-fine Cement Slurry

针对超细水泥浆液存在抗侵蚀能力差、后期体积倒缩等不足,文中通过掺加不同含量的膨胀剂UEA、奈系减水剂FDN-C、三异丙醇胺速凝剂TIPA,研究改性超细水泥浆液析水率、流动度、初终凝结时间、单轴抗压强度、膨胀率的变化规律。结果表明,随减水剂掺量增加,改性超细水泥浆液析水率最小值为17 ml,且流动度从234 mm下降至183 mm;凝结时间与速凝剂掺量成反比,U30F0.4T4.0配比的初凝时间最短,初凝时间为506 min,相比纯超细水泥浆液加快了33.68%。U30F0.8T4.0配比的3 d抗压强度峰值为10.46 MPa,U30F0.8T1.2配比的28 d抗压强度峰值为8.1 MPa,各龄期强度均不低于2.5 MPa,满足工程要求。当膨胀剂掺量为10%时,试块膨胀率最大,3~28 d试块膨胀率比纯超细水泥大0.803%~0.956%。研究成果可为特殊注浆加固止水工程提供一定参考。

Aiming at the shortcomings of superfine cement slurry,the water extraction rate,fluidity,initial and final setting time,uniaxial compressive strength and expansion rate of modified superfine cement slurry were studied by adding different contents of expansion agent UEA,nano water reducing agent FDN-C and triisopropanolamine accelerating agent TIPA.The results show that with the addition of water reducer FDN-C increasing from 0 to 0.8 g,the minimum water extraction rate of modified superfine cement slurry is 17ml,which is 37.04%lower than that of pure superfine cement slurry,and the fluidity decreases from 234 mm to 183 mm.The initial setting time of(U30F0.4T4.0)ratio is the shortest,and the initial setting time is 506 min,which is 33.68%faster than that of pure ultrafine cement slurry.The peak 3 d compressive strength of the U30F0.8T4.0 ratio is 10.46 MPa,and the peak 28 d compressive strength of the U30F0.8T1.2 ratio is 8.1 MPa,and the strength of each age is not less than 2.5 MPa,which meets the engineering requirements.When the expansion agent UEA content is 10%,the expansion rate of the test block is the largest,and the expansion rate of the 3~28 d test block is 0.803%~0.956%higher than that of the pure ultra-fine cement test block.The research results can provide some reference for special grouting reinforcement and water sealing projects.