Research and Application of Slag–Nanosilica Stabilizer for Silt Subgrade

Xiushan Wang,Shunxin Qi,Mingjie Wang,Keyu Chen,Bowen Dong,Jingyi Xu

doi:10.3390/app11178014

Abstract

With the rapid development of construction and road engineering, the accumulation of silting waste soil is becoming more and more serious. In order to recycle the silt, a new type of stabilizer was developed in this study to improve its mechanical properties and applicability on roads. The optimal ratio of stabilizer components was determined by orthogonal test and grey correlation analysis. The effects of stabilizer on the macroscopic mechanical properties of silt were investigated by unconfined compressive strength (UCS) test and split test. The water stability test and freeze–thaw cycle test were carried out to study the durability and road performance of stabilized soil. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods were used to study the effect of the stabilizer on the microstructure and mechanism of silt. The results showed that the optimal mixture ratio of the new type of stabilizer was quicklime: nanosilica: slag = 32:3:65. Adding 10% stabilizer is a reasonable and effective method to strengthen silt, which has the characteristics of high strength and strong durability in the early period. The addition of stabilizer will result in hydration reaction, pozzolanic reaction, and cation exchange on the surface of soil particles with silt, which will enhance the intermolecular force of soil particles, reduce the porosity of soil, and strengthen the connection between soil particles.

Highlights

Economic development and urban construction in China’s coastal areas have brought about the accumulation of silting waste soil
The silt occupies a large amount of land resources and causes huge economic losses and has practical engineering shortcomings, such as high moisture content, poor mechanical properties, and low comprehensive durability [2], which brings potential safety hazards to the construction project and people’s lives
In the face of the accumulation of large tons of silt, the above methods are not perfect in the implementation process; there are great safety risks, and they are not enough to deal with all the silt

Summary

Introduction

Economic development and urban construction in China’s coastal areas have brought about the accumulation of silting waste soil. The silt occupies a large amount of land resources and causes huge economic losses and has practical engineering shortcomings, such as high moisture content, poor mechanical properties, and low comprehensive durability [2], which brings potential safety hazards to the construction project and people’s lives. The commonly used methods for treating silt include soil displacement method [3], pile foundation method, structure optimization method [4], ocean dumping [5], etc. The treatment of silt in coastal areas has become a problem that urgently needs to be solved

Methods

Results

Conclusion