通过添加水溶性聚氨酯(PU)和外加剂以提高硫铝酸盐水泥(SAC)基材料的力学性能。采用流动度测试、力学性能测试、XRD矿物组分衍射、接触角分析和SEM显微观察等方法对其可注性、力学性能、化学结构、亲水性和表面形貌进行了研究;并且通过现场工程应用，研究了该材料对破碎煤岩体注浆加固的效果。研究结果表明：① PU的加入提高了该材料流动度,增加了硫铝酸盐水泥材料韧性，特别在早期较为明显。当PU的质量分数为10%时，PU-SAC的综合性能最好，硬化结石体拉强度在1,3,7 d分别增加了29.4%,50.7%,39.5%，对抗压强度无明显改善。② XRD定性物相分析表明随着PU的加入水化速率加快，水化产物种类与改性前一致;改性后浆液结石体表面静水接触角由11°增加到95°，润湿性由亲水性变为疏水性，可以更好地阻止水侵入注浆材料;③ 该材料具有微膨胀特性，体积膨胀率为1.17%;SEM微观结构形貌分析可知改性后的结石体内部结构裂隙较少，且有聚氨酯构成的网状结构镶嵌贯穿于水泥石内部，抑制微裂纹的发展;④ 现场试验表明，该材料性能稳定、泵送距离长、胶凝时间可控、力学性能好、体积微膨胀、强度不倒缩，提升了破碎煤岩体完整性和稳定性，降低了巷道变形量，为类似注浆加固成功提供了借鉴。注浆材料能够有效加固煤岩体，一方面是充填了裂隙，另一方面是黏结2个结构面增加了岩体黏聚力，但物理试验难以揭示加固机理，需要进一步研究。

By adding waterborne polyurethane (PU) and admixture to improve the mechanical properties of sulpho-aluminate cement matrix material,the fluidity test,mechanical performance test,XRD mineral component diffraction,contact angle analysis and SEM microscopic observation were used to study its injectability,mechanical properties,chemical structure,wettability and surface morphology.Based on the site experimental study,the effect of this material on the grouting reinforcement of broken coal and rock mass was studied.The results of the research show that:① the addition of PU improves the fluidity of the material and the toughness of the sulpho-aluminate cement material is increased,especially in the early stage.When the amount of PU added is 10%,the overall performance of PU-SAC is the best.The tensile strength of stones increased by 29.4%,50.7%,and 39.5% in 1 day,3 days,and 7 days.There is no obvious improvement in compressive strength.② XRD qualitative phase analysis shows that with the addition of PU,the hydration rate is accelerated and the types of hydration products are the same as those before the modification.After the modification,the static water contact angle of the surface of the slurry stone body is increased from 11° to 95°,the wettability is from hydrophilic to hydrophobic.It can better prevent water from invading the grouting material.③ The material has micro-expansion characteristics,the expansion rate is 1.17%.SEM microstructure and morphology analysis shows that in the modified stone body,the internal structure has fewer cracks,and the mesh structure composed of polyurethane penetrates inside the cement stone inhibits the development of micro-cracks.④ Field tests show that the material has stable performance,long pumping distance,and controllable gel time.With good mechanical properties,small volume expansion,and no strength shrinkage,this material improves the integrity and stability of broken coal and rock mass,reduces the amount of roadway deformation,and provides a reference for the success of similar grouting reinforcement.The reinforcement of the grouting material to the broken coal and rock mass is not only inert filling,but also able to bond the two structural surfaces.The simple physical tensile test cannot reveal the mechanism and needs further study.

1 材料来源和样品制备

   1.1 原材料

   1.2 配比

   1.3 试验方法

2 测试方法与结果

   2.1 浆液流动性

   2.2 基本力学参数测试

   2.3 XRD定性物相分析

   2.4 接触角

   2.5 膨胀性能试验

   2.6 SEM微结构

   2.7 改性机理

3 工程现场应用

   3.1 改性材料应用原理及技术

   3.2 工程概况

   3.3 注浆加固设计及效果评价

4 结论