ISS-水泥联合固化淤泥的力学特性研究

Mechanical properties of solidified silt with ISS and cement

采用离子土固化剂(ISS)和水泥对宁德海相淤泥进行化学固化,通过阿太堡试验确定最优ISS体积比;通过7 d龄期无侧限抗压强度试验确定临界水泥掺量。针对酸碱固化剂共存对淤泥固化的影响,对淤泥固化样品进行了物理、力学试验,分别研究酸性ISS、碱性水泥、NaOH碱化剂等单掺和复掺固化淤泥的力学特性及固化效果,探讨固化剂之间的影响机理。试验结果表明:酸性ISS与水泥之间相互抑制,ISS溶液中H+阻碍了水泥的水化进程,降低了固化土强度;NaOH碱化ISS和水泥联合固化淤泥与单掺水泥相比,不但弥补了水泥提高早期强度缓慢的不足,而且可节约大约3%的水泥用量。

The marine silt in Ningde was solidified with Ionic Soil Stabilizer (ISS) and cement. The optimal volume ratio of ISS was obtained through the test of Atterberg limits. The critical cement content was obtained by the test of unconfined compressive strength test at 7 d. Aiming at the influence of coexistence of acidic and alkaline solidifying agents on silt solidification, physical and mechanical tests were carried out on different solidified silt samples. The mechanical properties and solidification effects of single and compound solidified silts, such as acidic ISS, alkaline cement and NaOH alkalization agent, were studied respectively, and the interaction mechanism between solidifying agents was discussed. The results show that acidic ISS and cement restrain each other. H+ in ISS solution hinders the hydration process of cement and reduces the strength of solidified soils. Compared with the single cement, NaOH alkalinized ISS-cement makes up for the deficiency of the slow improvement of early strength by cement, and saves about 3% cement consumption for silt solidification.