Strength and Solidification Mechanism of Silt Solidified by Polyurethane

Abstract

To determine the mechanism and strength characteristics of solidification of silt by a permeable polyurethane grouting material, the effects of polymer content, soil moisture, and immersion time on the unconfined compressive strength (UCS) of the silt have been studied. The results showed that the permeable polymer grouting material can significantly improve the performance of silt: (1) A higher amount of polymer produced a greater strength in the solidified soil. (2) The strength of the solidified soil increased as the immersion time was increased. (3) Moisture in the soil was not conducive to improving the strength of the solidified soil. The X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) have proven that polyurethane does not react with the silt, but they could improve the strength of the silt through physical action. Mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) were performed to find that polymers can reduce soil porosity, and the addition of polyurethane improved the strength of the silt mainly through adhesion, wrapping, filling, and bridging.

A State-of-the-Art Review on the Study of the Diffusion Mechanism of Fissure Grouting

“…Wang et al [47] designed a water-soluble epoxy resin to modify cement-based grouting material, demonstrating superior strength, strain, flowability, stability, and bonding capacity compared with pure cement grouts. Li et al [48] investigated the influence of polymer concentration, soil moisture, and soaking duration on the strength of silt solidified with permeable polyurethane grouting materials and found significant improvements in silt performance. Guo et al [49,50] discussed the application of high-polymer injection technology in the treatment of hidden diseases, such as mud and the overturning of road surfaces, and the restoration of road-bearing capacity based on the performance and technical characteristics of high-polymer injection materials and comprehensive non-destructive testing techniques, such as ground-penetrating radar and hammer-type bending and sinking meters.…”

Study on Mechanical Properties of Permeable Polymer Treated Loess

“…The material for this grouting test is a permeable polymer independently developed by the team, with a slurry density of 1.0–1.2 g/cm 3 and a gelation time of about 2 h. The permeable polymers are divided into two components, A and B, which are dark yellow and have good fluidity. The chemical composition of permeable polymers is given by Li and Wang [ 18 , 32 ]. Permeable polymer can be fully permeated into the soil and the white colloidal material was produced when the polymer came into contact with water, which could greatly enhance the adhesion between soil particles, thus achieving the purpose of reinforcement.…”

“…Ren et al [ 17 ] studied the reinforcement mechanism and durability of loess reinforced by SH and lime. Li et al [ 18 ] solidified silt with polymer, and studied the effects of polymer content, water content, and soaking time on compressive strength. Chen et al [ 19 ] studied the feasibility of using red mud waste as loess subgrade filling and the mechanical characteristics of red mud-treated loess with a small amount of cement.…”

Effect of Nano SiO2 Enhanced Polyurethane Road Grouting Material on Folding Strength and Durability of Road Concrete

“…Because there are still unreacted isocyanate groups in the mud, it can chemically react with the aqueous solution to cross-link to form a water-insoluble synthetic polymer, which can achieve the purpose of anti-seepage engineering, plugging and plugging. Because the supercritical carbon dioxide gas produced during the chemical reaction increases the volume ratio, the solidification volume ratio is increased, and a higher expansion pressure is generated, which also increases the secondary dispersion of the mud, thereby increasing the dispersion range [22][23]. Because the slurry reacts with the aqueous solution and is stable under all conditions, it is not washed away by water when diluted with the solution.…”