缓凝型囊袋注浆填充料的配合比及性能研究

Mix Proportion and Performance of Delayed Setting Bag Grouting Filler

为了研发一种新型的囊袋注浆填充料,本文以水泥-膨润土作为主要填充材料,在研究单掺三乙醇胺以及复掺三乙醇胺-羟基乙叉二膦酸对填充料性能影响的基础上,通过正交试验研究了水灰比、膨润土掺量、羟基乙叉二膦酸掺量、聚羧酸减水剂掺量和三乙醇胺掺量5个因素对填充料性能的影响,确定了填充料的最佳配比,并借助XRD、LF-NMR、SEM测试手段进行微观结构分析。结果表明:三乙醇胺能够改善填充料的孔隙结构并提高早期强度,膨润土能够降低填充料的泌水率,羟基乙叉二膦酸能够显著延长填充料的初凝时间,聚羧酸减水剂能够增强填充料的流动性;填充料的最佳配比为水灰比0.9、膨润土8%(占水泥的质量分数,下同)、羟基乙叉二膦酸0.15%、聚羧酸减水剂1.0%、三乙醇胺0.02%,优化后的填充料初凝时间为138.42 h,7 d抗压强度为5.7 MPa。

In order to develop a new type of bag grouting filler,cement-bentonite was used as main filling material.On the basis of studying the influence of single doped triethanolamine(TEA),codoped TEA and 1-hydroxyethylidene-1,1-diphosphonic acid(HEDP)on the performance of the filler,through orthogonal test,the effects of five factors,namely water cement ratio,bentonite content,HEDP content and polycarboxylate superplasticizer(PCE)content and TEA content on the performance of the filling material were studied,and the best mix ratio of the filler was determined.Finally,the microstructures were analyzed by XRD,LF-NMR and SEM testing methods.The results show that TEA can optimize the pore structure of the filler and improve its early strength,bentonite can significantly reduce the bleeding rate of the filler,HEDP can significantly delay the initial setting time of the filler,and PCE can enhance the fluidity of the filler.The optimal proportion of filler is water cement ratio 0.9,bentonite 8%(accounts for cement mass fraction,the same below),HEDP 0.15%,PCE 1.0%,TEA 0.02%.The initial setting time of the optimized filler is 138.42 h,and the 7 d compressive strength is 5.7 MPa.