盾构渣土同步注浆料制备及性能分析

Preparation and Performance Analysis of Synchronous Grouting Material With Shield Muck

为解决盾构渣土外运和堆放造成的成本和环境污染问题,并实现固废物资源化再利用。利用盾构渣土替代全部砂、稻壳灰(RHA)替代部分水泥,制备管片壁后同步注浆料,并对制备的注浆料进行相关性能分析。试验结果表明:1)稻壳灰(RHA)的掺入对浆液的稠度和凝结时间影响较大,即RHA掺量(质量分数)越高,浆液稠度越小、凝结时间越短。2)当RHA替代率为25%时,稠度降低27.5%,凝结时间缩短31.5%,RHA掺量对浆料强度呈先降低后升高的趋势,浆料28 d强度不低于RHA替代率为0的浆料强度。3)随着渣土粒径增大,浆料稠度和凝结时间降低,但浆料强度提高。经试验确定注浆料配比为:水胶比2.5、RHA掺量25%、渣土粒径2.36~9.5 mm,不仅改善了浆液的稠度(105 mm),还大幅提高了后期强度(3.35 MPa),且浆液各项指标均符合要求,为盾构渣土再利用提供了一种新思路。

In order to lower of cost and minimize the impact on urban environment caused by shield muck transportation and accumulation,and to achieve the recycling of solid waste,the synchronous grouting material was prepared by using shield muck to replace overall sand and rice husk ash(RHA)to replace part of cement,and the related properties of prepared slurry were analyzed.The results show that:(1)The addition of RHA has great influence on consistency and setting time,i.e.,the higher the content of RHA,the smaller the consistency and setting time.(2)When the RHA replacement rate is 25%,the consistency is reduced by 27.5%,and the setting time is shortened by 31.5%;the strength of grouting material decreases first and then increases with RHA content increasing;the strength of grouting material at 28 d is not lower than that of grouting material without RHA.(3)With the increase of muck particle size,the consistency and setting time of grouting material decrease,while the strength of grouting material increases.The experiment determined the ratio of grouting material:water-binder ratio 2.5,RHA content 25%,and muck particle size 2.36-9.5 mm,which not only improved the consistency of grouting material(105 mm),but also significantly increased the strength(3.35 MPa).The indices of grouting material met the requirements,providing a new idea for the reuse of residue in shield tunneling.