应急自动堵漏材料的设计制备及模拟实验

摘要

目的 设计制备一种基于磷酸镁水泥的应急自动堵漏材料,并进行室内模拟实验.方法 通过加入核桃壳粒和膨润土,为应急堵漏材料提供骨架支撑,调整材料密度.基于此进行单掺实验遴选抗分散组分、填料组分和膨胀组分种类,并确定各自掺量范围.而后,以聚丙烯酰胺 (PAM)掺量、核桃颗粒级配和吸水树脂(SAP)掺量作为正交试验设计因素,开展三因素三水平正交试验,得到应急自动堵漏材料的基本配方.最后,根据不同漏口位置、漏口形状、漏口大小,掺加纤维搭建漏口阻挡体系,加入漂珠调节堵漏材料密度实现自动堵漏.通过初凝时间和终凝时间测试、置换法和pH值测试,分别测定应急自动堵漏材料凝结时间、密度和抗分散性,依据堵漏渗水的多少判定堵漏效果.结果 通过单掺试验遴选材料和正交试验调整掺量,最后得到基于磷酸镁水泥应急自动堵漏材料基础配方为100%MPC+60%核桃壳颗粒+40%~100% 漂珠+5%膨润土+0.6% PAM+4% SAP+3%~4%硼砂+0.4%减水剂+0~5%纤维,水固比为0.2~0.25,对基础配方改进后能对底部、侧部不同尺度漏口进行封堵.结论 纤维能在漏口形成网架结构,实现刚性填料和弹性膨胀组分拦阻,核桃颗粒等填料可以在漏口内部狭窄处进行架桥,提供封堵层骨架,SAP 等膨胀组分吸水可较密实地填充漏口,漂珠可以有效调节应急堵漏材料密度.%ABSTRACT: Objective To design and prepare a kind of emergency automatic plugging material based on magnesium phos-phate cement and carry out indoor simulation experiment. Methods Walnut shell and bentonite were provided as skeleton sup-port of emergency plugging material to adjust the density of the material. Based on this, the single doping experiment was con-ducted to select anti-disperse component, packing component and expansion component type, and determine the respective dos-age range. Then, the polyacrylamide (PAM) dosage, walnut grain size distribution and water absorbing resin (SAP) content were taken as orthogonal experiment design factors. Three factors and three levels of orthogonal experiments were carried out to get emergency automatic plugging material basic formula. Finally, according to different location of leakage, the shape of leak, the size of leakage hole, and the addition of fiber, the leakage plugging system was built. The density of the material was adjusted to achieve automatic plugging by adding drift beads. Through the initial setting time and final setting time test, the displacement method and pH value test, the setting time, density and resistance to dispersion of emergency automatic plugging material were determined to judge the plugging effect according to water seepage. Results After the single doping test selection and the or-thogonal experiment adjustment, the basic formula of emergency automatic plugging materials based on magnesium phosphate cement was obtained: 100% Magnesium phosphate cement + 60% Walnut shell particles + 40%-100% Drift beads + 5% Bentonite + 0.6% PAM +4% SAP + 3%- 4% Borax + 0.4% Water reducing agent + 1%-5% Fiber, and water cement ratio was 0.2- 0.25. After improvement of the basic formula, different scales of leakage at the bottom and side can be blocked. Conclusion Fiber can realize the rigid structure in the leakage to achieve blocking of rigid filler and elastic expansion composition. Walnut grain and other filler might be bridges in inside the leaks to provide a layer of seal skeleton. SAP expansion components such as water absorption could fill the leaks tightly. Drift beads could effectively adjust the density of casualty plugging material.