基于上海地区流态固化土的多元矿渣水泥基固化剂研究

Multi-component Slag Cementitious Stabilizer for Fluidized Stabilized Soil in Shanghai

摘要:

本研究设计并优化了一种多元矿渣水泥基固化剂，采用四因素三水平正交试验优化固化剂配合比，并通过流动性、凝结时间、抗压强度测试及微观表征手段，研究了固化剂掺量（8%~14%）和水固比（0.45~0.55）对上海二层软土流态固化性能的作用规律与增强机理。通过正交试验与方差分析，确定最优固化剂配合比，即水泥、矿渣粉、早强剂、流动剂的质量比为9.0∶12.0∶3.0∶1.5。当固化剂掺量增至14%时，固化土28 d抗压强度达1.74 MPa（较8%掺量下提升172%）；流动剂与聚羧酸减水剂协同作用，使流动度提升至312 mm。微观分析证实，固化剂水化生成的水化硅铝酸钙（C-A-S-H）凝胶与钙矾石协同作用，有效填充孔隙并形成致密网状结构，从而提高了流态固化土的强度。

Abstract:

A multi-component slag cementitious stabilizer were designed and optimized . A four-factor three-level orthogonal test was applied to optimize the agent’s mix proportion. The effects of stabilizer content （8%-14%） and water-to-cement ratio （0.45-0.55） on the properties and enhancement mechanisms of fluidized stabilized soil formed from the second-layer soft soil of Shanghai were investigated through fluidity， setting time， compressive strength tests， and microstructural characterization. The results demonstrate that the optimal mix proportion is that the mass ratio of cement， slag， early-strength agent， fluidizing agent is 9.0∶12.0∶3.0∶1.5. When the stabilizer content increases to 14%， the 28 d compressive strength reaches 1.74 MPa， representing a 172% increase compared with that at 8% content. The synergistic effect of fluidizing agent and polycarboxylate superplasticizer enhances fluidity to 312 mm. Microstructural analysis confirms that the calcium-aluminum-silicate-hydrate（C-A-S-H） gel and ettringite generated by the hydration of the stabilizer effectively fill pores and form a dense network structure， thereby improving the strength of the fluidized stabilized soil.