论文部分内容阅读
利用土壤板结原理,通过对硫铝酸盐水泥固化土无侧限抗压强度试验和水稳定性试验,探讨钾盐、磷酸盐对其早期强度的影响规律;通过X射线衍射(XRD)对固化土的物相成分进行了分析,探讨钾盐、磷酸盐影响固化土强度的变化内在机制。试验结果表明,钾盐、磷酸盐对固化土强度提高的阈值为0.6%,当盐掺入量低于该阈值时,固化土强度会随着盐掺量的增加而提高,当盐掺入量超过该阈值时,固化土强度会逐渐降低。盐掺入量不超过2%时,掺盐固化土水稳定性与未掺盐固化土差不多,7 d固化土软化系数基本保持在70%以上,但掺入K2SO4的固化土水稳定性较差,软化系数在60%左右。生成高强难溶具有膨胀性的矿物晶体是掺盐固化土早期强度提高的主要原因,但盐掺入量过高,固化土中矿物晶体过多膨胀作用,破坏固化土结构,而使固化土早期强度降低。
By using the principle of soil compaction, the unconfined compressive strength test and water stability test of sulphoaluminate cement stabilized soil were conducted to investigate the effect of potassium salt and phosphate on their early strength. XRD, The phase composition of soil was analyzed to explore the intrinsic mechanism of potassium salt and phosphate affecting the strength of cured soil. The test results show that the threshold value of potassium salt and phosphate on the strength of hardened soil is 0.6%. When the content of salt is lower than the threshold, the strength of hardened soil increases with the increase of salt content. When the threshold is exceeded, the strength of the soil will gradually decrease. When the content of salt is less than 2%, the water stability of salt-cured soil is similar to that of salt-hardened soil, and the softening coefficient of soil is basically over 70% after 7 d, but the stability of soil mixed with K2SO4 is poor , Softening coefficient of about 60%. The formation of high-strength refractory and expansive mineral crystals is the main reason for the early strength increase of salt-hardened soil. However, the salt content is too high, the excessive expansion of mineral crystals in the hardened soil damages the structure of the hardened soil, Reduced strength.