三乙醇胺和快硬硫铝酸盐水泥对盾构壁后注浆浆体性能的影响

Influence of Triethanolamine and Rapid Hardening Sulfoaluminate Cement on Performance of Backfill Grouting in Shield Engineering

针对盾构壁后注浆浆体(浆体)须具有较短凝结时间并保持良好流动性的难题,以快硬硫铝酸盐水泥(R·SAC)和三乙醇胺(TEA)为外加速凝材料,分析两者对浆体性能影响规律及微观机制。结果表明,随R·SAC替换P.O水泥至50%,浆体凝结时间从9.5 h降低至2.0 h,但150 min流动度损失约50%;TEA以0.6%掺量为拐点,浆体凝结时间和流动度均先增大后减小;复掺情况下,两者对浆体水化具有协同作用,起始期快速水化,凝结时间缩短,TEA解絮作用提高了浆体流动性,减缓流动度经时损失;复掺15%R·SAC和0.05%TEA,可制备出凝结时间6 h、150 min流动度250 mm的快凝高流动性浆体。

Aiming at the problem that the backfill grouting of the shield project must have a short setting time and maintain good fluidity, Rapid hardening sulfoaluminate cement(R·SAC) and triethanolamine(TEA) are used as external accelerated setting materials, Analysis of the influence law and microscopic mechanism of the two on grout properties. The results show that with the increase of R·SAC, the setting time of the grout decreases from 9.5 h to 2.0 h, but the fluidity loss at 150 min is about 50%;With 0.6% dosage of TEA as the inflection point, the setting time and fluidity of the grout both increased first and then decreased;In compound blending, The two have a synergistic effect on grout hydration, rapid hydration in the initial stage, shortened setting time,and TEA deflocculation improves grout fluidity and slows down the loss of fluidity over time;By adding 15% R·SAC and 0.05%TEA, a fast-setting and high-fluidity backfill with a setting time of 6 h and a fluidity of 250 mm in 150 min can be prepared.