Introduction to cement-based grouting materials

2022-11-22
Introduction to cement-based grouting materials

Keywords
Grouting material, cement, polycarboxylate superplasticizer, CSA expansion agent, silica fume, lignin fiber, HEMC

Overview
Cement-based grouting material is a dry-mixed material composed of cement as the cementitious material, adding high-strength aggregates, admixtures, etc. After adding water and mixing, it has the characteristics of high fluidity, early strength, high strength, and micro-expansion.

Application range
Applied to mechanical equipment installation and construction concrete structure reinforcement
Adhesive grouting for small gaps such as track foundations
Embedding of construction joints in subways, tunnels, and underground projects
Anchor bolt anchoring
Reinforcement and repair grouting of concrete beams, columns, slabs, walls, etc.

Raw material selection
Base material: OPC + graded sandstone

Silica fume
Micro-silica fume can fill the pores between cement particles, and at the same time form a gel with hydration products, which can significantly improve the performance of compression resistance, flexural resistance, impermeability, anti-corrosion, impact resistance and wear resistance. It has the functions of water retention, preventing segregation and bleeding, and greatly reducing pumping resistance.

CSA expansion agent
When the cement sets and hardens, the CSA expansion agent can produce volume expansion, play the role of compensating shrinkage and tensioning steel bars to generate prestress and fully filling the cement gap.

Polycarboxylate superplasticizer powder
Reduce the water consumption of grouting materials, improve the high fluidity and superplasticity of grouting materials.

Hydroxyethyl Methyl Cellulose Ether, HEMC
Hydroxyethyl methyl cellulose ether has excellent solubility, salt resistance, water retention, etc., and it mainly plays the following roles in grouting materials:
Improves the uniformity of the grout, making the concrete easier to spread, while improving sag resistance. Enhances flow and pumpability for increased productivity.
High water retention, prolonging the working time of the grouting material, improving work efficiency, and helping the grouting material to form high mechanical strength during the setting period. Air infiltration is controlled, thereby eliminating micro-cracks in the coating, resulting in an ideal smooth surface.

Lignin fiber
Lignin fibers can absorb and transport liquid through their own capillary action. Once the three-dimensional network structure is in a static state, such as cement mortar is solid, lignin fibers can be tightly adhered to the grouting material as a closed layer, which can  Protects against moisture and rain penetration. The three-dimensional network structure of lignin fibers can effectively absorb and weaken the mechanical energy generated during the curing and drying process, thereby reducing segregation.