Soil curing agent is added to the soil in the form of admixtures, broadly speaking, all materials that can improve the technical properties of the soil are the category of soil curing agents, cement, lime, etc. can be said to be the most commonly used soil curing agents.
The soil curing agent introduced in this paper belongs to the liquid organic polymer polymer curing agent, the main agent of the liquid curing agent is the polymer synthesized by polymer, and the additives are generally inorganic salts such as magnesium sulfate or calcium carbonate. After acting on the soil, on the one hand, the soil particles are intertwined and crossed by the polymer chain, and finally the reinforced soil forms a solid space skeleton, so as to improve the integrity of the soil particles and achieve the effect of reinforcing the soil. The various processes of soil reinforcement are complex and diverse, and can be divided into three kinds of processes: chemical process, physicochemical process, and physico-mechanical process according to the different properties of soil and the different reaction properties.
The chemical process can generally be divided into three situations: the chemical reaction of the curing agent material itself, the chemical reaction between the curing agent material and the soil particles, and the chemical reaction of the soil particles themselves, and the polymerization and polycondensation of polymer compounds belong to the reaction of the curing agent itself. The physicochemical process is generally the adsorption process of soil particles on different binders, which is mainly divided into physisorption, physicochemical adsorption and chemical adsorption. Physical adsorption is a process in which soil particles adsorb binders on their surface under the action of molecular force, so that the free energy on the surface is reduced. Physicochemical adsorption is the process of cation exchange between certain components in the binder and the adsorption of the surface of the soil particles. Chemical adsorption is a reaction process in which a chemical reaction occurs between the adsorbent and the adsorbed substance to generate a new insoluble substance, and a chemical bond is formed between the adsorbent and the adsorbed substance. The physical and mechanical processes mainly include crushing the soil mass, mixing and the process.
The solidification process of soil curing agent to soil is a comprehensive manifestation of the above three processes, when the curing agent is mixed with the solidified soil mixture, two types of reactions are carried out between itself and the clay minerals in the solidified soil mixture: first, a chemical reaction occurs between the soil curing agent and the clay components, so that the chemical bond with higher strength can be formed, so that the integrity of the soil body is strengthened, and the soil body has played a certain role in reinforcing it, At the same time, there is also a chemical erosion process of clay minerals by acidic compounds, and secondly, the organic polymer substances in the soil curing agent will also have the dual effect of physical winding and adsorption on clay components. The surface of clay minerals is eroded by the components in the curing agent, which makes its surface rougher and enhances its adsorption of heterosexual components, which is also conducive to the winding and adsorption between polymers and clay minerals.
However, the reaction between soil curing agent and clay minerals alone is not enough to form a stable spatial grid structure. Usually the soil curing agent and the inorganic alkaline curing agent such as cement act together, the hydration and hydrolysis reaction, ion exchange, agglomeration, hard setting reaction, carbonation and crystallization of cement are carried out at the same time as the solidification of the soil by the soil curing agent, and can play a role in promoting each other, and the chemical erosion of the soil curing agent on the clay minerals in the mixture makes the crystal surface of the clay mineral have a certain amount of lattice defects. This promotes the further reaction of various products of cement hydration with various clay substances with lattice defects. Its products adhere to the surface of the original crystal and continue to grow, absorbing the components of the original crystal and forming a common boundary with the original crystal. The shared boundary gradually increases with the chemical reaction and adsorption winding, and then forms a grid skeleton structure. Under the joint reaction of alkaline materials and soil curing agent self-initiator, the organic monomer substances in the soil curing agent polymerize into polymer molecular chains, which are adsorbed on the surface of the crystals of clay minerals or wound around the crystals. The surface of the eroded rough clay-like minerals is also more susceptible to adsorption and entanglement. Under the co-curing action of soil curing agent and cement, the mixture can form a dense and stable grid skeleton structure.
The laboratory test study of the curing agent was carried out, and the change law of the unconfined compressive strength was combined with the amount of lime % and the amount of curing agent 10000, and the test results showed that the unconfined compressive strength was increased with the increase of lime content and curing agent content, and the strength of the solidified soil could be greatly increased by adding a small dose of curing agent under the condition that the lime content remained unchanged.
The strength and freeze-thaw test of the curing agent solidified soil were studied, and the lime content was 6% and the curing agent content was 15 10000, the test results show that the 7-day unconfined compressive strength of the curing agent solidified soil can reach 191MPa, after freeze-thaw cycles, the freezing stability coefficient is 076。
Statement: We respect originality and also pay attention to sharing, and thank each author for their hard work and dedication. We are committed to protecting the author's copyright, only for the dissemination and sharing of new technologies and knowledge, without any other commercial profit, if there is any infringement, please contact and delete in time.