改性水泥-水玻璃注浆材料防渗性能试验研究

Experimental Investigation of Anti-seepage Performance of Improved Cement-silicate Grouting Material

为了使水泥-水玻璃注浆材料在注浆中得到更广泛的应用,通过室内配比试验和扫描电镜分析对5%膨润土掺量下水泥-水玻璃体积比和粉煤灰掺量对水泥-水玻璃(C-S)浆液性质的影响进行研究,并开展现场试验对该改性浆液的防渗性能进行了研究。结果表明:(1)改性C-S双液的凝胶时间有所延长,且凝胶时间随着C-S体积比的增大而缩短、粉煤灰掺量的增大而延长;(2)浆液结石体的抗压强度和抗折强度都随C-S体积比的增大都呈现先增大后减小的趋势并在体积比约为2时达到最大,浆液结石体的抗压强度随粉煤灰掺量的增大而降低,结石体7 d抗折强度随着粉煤灰掺量的增加先增加后减小,试验条件下,粉煤灰掺量为25%取得最大抗折强度;(3)通过扫描电镜对结石体微观结构分析得出,粉煤灰掺量为25%、C-S体积比为2的配比下水泥的水化反应最充分,粉煤灰的微集料反应发挥最佳;(4)通过现场防渗试验验证了研发浆液材料的防渗性能满足规范要求。改性C-S浆液较好地结合了几种材料的优点,建议采用的材料配比为25%粉煤灰、5%膨润土、70%水泥,C-S体积比为2。

In order to make cement-silicate grout be used more widely,laboratory experiment and SEM analysis were conducted to investigate the effect of volume ratio between cement and sodium silicate as well as the proportion of fly ash to cement-silicate grout with 5%bentonite.In addition,field test was carried out to estimate the anti-seepage performance of the improved cement-silicate grout.Based on the experimentally obtained result,it is shown that the gelation time prolongs with the increase of volume ratio and decrease of fly ash.The concretion strength first increases and then decreases with the increase of the volume ratio between cement and sodium silicate,and reaches maximum when the volume ratio is about 2.The compressive strength of concretion decreases with the increase of fly ash,while 7 d flexural strength first increases and then decreases with the increase of fly ash,and reaches maximum when the proportion is approximately 25%.From the SEM analysis,conclusion could be drawn that the hydration reaction of cement is relatively thorough and micro-aggregate effect of fly ash is comparatively completed when the volume ratio is 2 and the proportion of fly ash is 25%.In the field test,the anti-seepage performance of the improved cement-silicate grouting material is remarkable.The results provide references for the applications of grouting reinforcement in hydraulic engineering.