与水泥固化土强度相比,由胶结性组分和膨胀性组分构成的复合型固化剂固化软土得到的固化土强度可能大幅度提高,也可能降低。本研究试图探讨影响复合型固化剂固化效果的原因。采用三种复合型固化剂固化两种土样,通过对固化土强度发展规律的试验、采用XRD和DSC-TG等方法对水化硅酸钙CSH和钙矾石AFt生成速率的测试,得出:复合型固化剂的固化效果取决于固化土中AFt生成速率与CSH生成速率间的协调性,如果AFt生成时,CSH的生成量还很少、所形成的胶结结构还很微弱,则AFt生成过程产生的体积膨胀将对固化土强度产生增强作用;反之亦然。
The stabilized soil strength of compound soft soil stabilizer,which is composed of cementitous component and expansible component,may be increased significantly,but also may be reduced.The causes for different stabilization effects are studied.Three compound stabilizers are used to stabilize two soil samples.The unconfined compressive strength is tested,and the generation rate of calcium silicate hydrate CSH and ettringite AFt are tested by XRD tests and DSC-TG tests.The results show that the stabilization effect of compound stabilizer depends on the coordination between AFt generation rate and CSH generation rate.If CSH generation quantity is still little and the cementitous structure is very weak when AFt is generated,the volume expansion caused by the AFt generation process will increase the stabilized soil strength;and vice versa.