石灰-水泥复合土增强机制研究

利用比强度方法分析水泥土及石灰水泥土无侧限抗压强度，对石灰水泥土的增强机制进行了研究。采用内蒙古河套粉质黏土拌制水泥土及石灰水泥土试件，水泥土和石灰水泥土掺入不同量的氢氧化钙、碳酸钙和水泥，并按标准养护28 d，进行单轴抗压试验，测得水泥土及石灰水泥土的无侧限抗压强度值。研究结果表明：石灰水泥土和水泥土中存在化学胶凝和物理填充两大类作用。其中石灰水泥土中存在水化作用、硬凝作用、离子交换及团粒化作用和复合作用等4类化学增强作用；水化作用是水泥土和石灰水泥土强度增长的最主要来源；熟石灰能够抑制水化作用。

Reinforecment mechanism of lime-cement soil

Based on the unconfined compressive strength of cemented soil and lime-cement soil that are analyzed by tenacity method, the study of the curing mechanism of lime-cement soil is carried out. In the aspect of unconfined compressive strength, the experiment of cemented soil specimens and lime-cement soil specimens which are made according to the ratio of cemented soil and lime-cement soil, has been completed after 28 days’ standard curing. Ca(OH)2, CaCO3,and cement were chosen as addtives with different levels to be mixed in the cemented soil and lime- cement soil. Its compressive strength is tested and the experiment result is analyzed. The research results indicate that the strength of cemented soil and lime- cement soil originates mainly from the composite binding effect and the physical filling effect in the cemented soil. The physical filling effect, pozzolanic effect and particle of clay ionic exchange and quadrate reaction, action of cement hydrate and combined action exist in lime-cement soil. The research results also indicate that the action of cement hydrate is the mian reason for the increasing rule of the strength of cemented soil and lime-cement soil; and the hydrated lime can restrict cement hydration but doesn’t stop cement hydration.