利用红黏土弃渣制备岩溶区注浆材料配比及其性能研究

在岩溶地区进行灌注桩施工时,注浆法可有效改善混凝土易流失、断桩、桩身孔洞等问题,但传统注浆材料成本较高且性能过剩,而且施工现场往往存在大量弃渣需要妥善处理。鉴于此,提出利用红黏土弃渣为基材,以水泥、粉煤灰为主固化剂,辅以水玻璃,制备新型注浆材料。通过正交试验,探究各组分对浆液关键性能指标的影响,确定最佳配比,并对最优配比下浆液结石体的微观结构进行分析。结果表明:水土比是影响浆液性能的主控因素;水泥掺量对浆液结石体的强度影响最大;粉煤灰可以增加浆液结石率,并提高结石体的后期强度;水玻璃主要起到加速凝结的作用。推荐的最佳配比为水土比0.6(质量比),水泥掺量10%(质量分数),粉煤灰掺量12%(质量分数),水玻璃掺量1.1%(质量分数)。经综合分析,该浆液具有流动性好、填充性好、强度适中、造价低廉等特点,适合工程大规模使用。

Proportion and Performance of Grouting Materials Prepared by Red Clay Slag in Karst Area

During the construction of bored piles in karst area, grouting method can effectively improve the problems such as easy loss of concrete, broken pile, holes in pile body and so on, but the cost of traditional grouting materials is high and the performance is excessive; on the other hand, there are often a lot of abandoned slag in the construction site that need to be properly disposed of. A new type of grouting material was prepared by using red clay slag as base material, cement and fly ash as main curing agents and sodium silicate as auxiliary. Through the orthogonal test, the influence of each component on the key performance index of slurry was explored, the optimum proportion was determined, and the microstructure of slurry stone body under the optimal proportion was analyzed. The results show that the water-soil ratio is the main factor affecting the performance of slurry. The content of cement has the greatest influence on the strength of slurry stone body. The fly ash increases the concretion rate of slurry and improves the later strength of stone body. The sodium silicate mainly plays a role in accelerating setting. The optimal proportion of slurry is water-soil mass ratio of 0.6, cement content of 10% (mass fraction), fly ash content of 12% (mass fraction) and sodium silicate content of 1.1% (mass fraction). After comprehensive analysis, the slurry has the characteristics of high fluidity, good fallibility, moderate strength and low cost, which meets the large-scale use of the engineering.