粘土水泥复合浆材强度研究

Study on strength of clay-cement grouting material

通过室内试验,研究了水灰比、龄期、粘土加量、压滤效应等对粘土水泥浆材结石无侧限抗压强度的影响。分析试验结果表明,粘土水泥浆无侧限抗压强度和浆液水灰比随着龄期的变化规律呈指数关系。在完全压滤作用下,抗压强度随着压力的增大而大幅提高,且强度随龄期呈二次多项式规律变化,如在0.8 MPa压力作用下,粘土水泥浆材结石28 d无侧限抗压强度增大3倍左右;抗压强度随着粘土加量的增大而减小,粘土加量在50%~60%间出现大幅下降。研究表明,在注浆工程中采用粘土水泥浆材时,应尽可能创造条件产生较充分的压滤效应,控制粘土加量不超过50%,水灰比在2∶1左右,可以获得足够的强度指标。适量添加粘土,这类浆材完全可以用于注浆加固工程中。

Through lab experiment, the impacts from the water-cement ratio, age, clay content, filter-pressing effect, etc. on the unconfined compressive strength of the calculus of clay-cement grouting material are studied herein. The result from analysis and experiment demonstrates that the law of the changes of the unconfined compressive strength and the water-cement ratio of the grou- ting material along with the age shows an exponential relationship. Under a full filter-pressing effect, the compressive strength is to be largely increased along with the increase of pressure, furthermore, the strength changes along with the law of the quadratic polynomial; e.g. under the pressure effect of 0. 8 MPa, the unconfined compressive strength of the calculus of el^y-cement grou- ting material of 28 d is to be increased by about 3 times, while the compressive strength is to be decreased along with the increase of the clay content, and it is to be largely decreased, when the clay content is between 50% ~ 60%. The study result shows that when the clay-cement grouting material is adopted for a grouting project, it is necessary to try to create a condition for producing a more sufficient filter-pressing effect, simultaneously, control the clay content not over 50% with the water-cement ratio about 2 ： 1, thus enough strength index can be surely obtained. With proper clay content, this kind of grouting material can be satisfac- torily applied to the grouting project concerned.