高含水率淤泥固化后pH值和电导率与强度特性的关系

Relationships of pH value and Electrical Conductivity with Strength Characteristics of High Water Content Sludge after Stabilization

摘要:

采用水泥对高含水率淤泥进行固化，测定了固化土的无侧限抗压强度、pH值和电导率，研究了水泥掺量和养护时间对固化土pH值和电导率的影响，探讨了固化土pH值和电导率与无侧限抗压强度之间的定量关系。结果表明：随着水泥掺量的增加，固化土的pH值和电导率均增大；当固化土的pH值达到11.16左右，电导率达到0.563 S/m左右（水泥掺量7.5%左右）时，固化土的无侧限抗压强度才逐渐增加；随着养护时间的增加，高水泥掺量（10.0%~60.0%）固化土的电导率在0~7 d内增加，随后逐渐降低，低水泥掺量（低于10.0%）固化土的电导率则缓慢增加到14 d，随后才开始降低；固化土的pH值和电导率根据4个养护时间分别对无侧限抗压强度呈现较好的指数函数关系。

Abstract:

The solidification of high water content sludge with cement was investigated， and the unconfined compressive strength， pH value， and electrical conductivity of the solidified soil were measured. The effects of cement dosage and curing time on the pH value and electrical conductivity of the solidified soil were studied， and the quantitative relationship between the pH value and electrical conductivity of the solidified soil and its unconfined compressive strength was explored. The results show that as the cement dosage increases， both the pH value and electrical conductivity of the solidified soil increases. When the pH value of the solidified soil reaches approximately 11.16 and the electrical conductivity reaches around 0.563 S/m （with a cement dosage of about 7.5%）， the unconfined compressive strength of the solidified soil gradually increases. With increasing curing time， the electrical conductivity of high cement dosage（10.0%-60.0%） solidified soil increases within 0-7 days and then gradually decreases， while that of low cement dosage（less than 10.0%） solidified soil slowly increases up to 14 days before beginning to decline. The pH value and electrical conductivity of the solidified soil exhibites a favorable exponential relationship with the unconfined compressive strength at four different curing times.