流态固化土流动性和强度的影响因素及机理研究

Influencing Factors and Curing Mechanism of Fluidity and Strength of Fluidized Stabilized Soil

摘要:

通过流动度、无侧限抗压强度和显微分析等试验,研究了土样特性、固化材料类型、灰土比、水固比和温度等因素对流态固化土流动性和强度的影响规律,并分析其固化机理。结果表明：流态固化土流动性随水固比增加而增大,随灰土比增加略有降低,随土样粒径减小显著降低。流态固化土强度随灰土比增加而增加,且固化剂较水泥可在高水固比、低灰土比和低养护温度下快速形成更高强度,其固化机理在于固化剂较水泥可生成更多AFt,基于AFt生成过程中消耗大量水、AFt对土颗粒间隙挤密填充和C-S-H胶结土颗粒等作用,可显著提高流态固化土微观密实性和强度。

Abstract:

Through tests on flowability, unconfined compressive strength, and microscopic analysis, this study investigates the effects of soil characteristics, type of solidification material, solidification material-soil ratio(SM/S), water-solid ratio(W/S), and curing temperature on the flowability and strength development of fluidized solidified soil (FSS). The results show that the flowability of FSS increases with a higher W/S, slightly decreases with an increase in SM/S, and significantly decreases with a reduction in soil particle size. The strength of FSS increases with a higher SM/S. Compared to cement, the stabilizer can achieve higher early strength even under high W/S ratios, low SM/Ss, and low curing temperatures. The solidification mechanism lies in the stabilizer's ability to produce more ettringite (AFt), which contributes to strength development by consuming free water during formation, densifying inter-particle pores, and bonding soil particles through calcium silicate hydrate (C-S-H). These effects significantly enhance the compactness and strength of FSS.