effect of microsilica on properties of grout-pg电玩城

as a strong and important part of concrete, microsilica can improve the anti-bending, anti-seepage, anti-corrosion, anti-impact and anti-wearing properties of buildings. protect water, prevent segregation, bleeding, greatly reduce concrete pumping resistance. the ground dust of spraying concrete and castable is greatly reduced, and the thickness of single spraying layer is increased. it has a strong volcanic ash effect. when mixed with concrete, secondary hydration reaction can occur with ca(oh)2, cement hydration product, form gelling product, fill cement stone structure, improve the microstructure of slurry, improve the mechanical property and durability of the hardened body, etc.

in china, due to its low yield and high price at present, when the strength of reinforced grouting materials is lower than 80mpa, the addition of microsilica  ash is not considered. microsilica silica ash can produce many good effects on the properties of reinforced grouting. the effect of amorphous and extremely fine microsilica silica fume on high performance cementing grouting is mainly physical and chemical: it plays the role of superfine filler, plays the role of crystal nucleus in the early hydration process, and has high volcanic ash activity.

1. hydration of micro-microsilica silica fume to accelerate the cementitious material system:

after substituting microsilica for equivalent cement, the hydration and exothermic heat of system 3d and 7d were greatly increased. it is necessary to control the heat release in the early stage of hydration.

2. improve the strength of reinforced grouting with silica dust

when microsilica is used in combination with efficient water reducing agent, the microsilica silica fume reacts with hydration products to form hydrated calcium silicate gel, fill the gap between cement particles, improve the interface structure and cohesive force, and form a dense structure. therefore, the strength of reinforced grouting can be improved significantly. ordinary microsilica content is 5%-10%. the super - high strength reinforced grouting material with compressive strength up to 100mpa can be prepared.

3. increasing density of silica fume silica fume:

microsilica particles are small enough to fill the gap between the cement particles. granules are packed tightly, reducing bleeding and reducing capillary and average pore size. good mixing effect can be obtained when the dosage of silica fume is between 5% and 10%. water reducing agents should be used to ensure the dispersion of microsilica and cement.

4. improvement of segregation and bleeding performance of reinforced grouting by silica fume silica fume:

after pouring the reinforced grouting material, water is often separated from the reinforced grouting material, that is, water film is formed on the surface layer, also known as floating grouting, which makes the distribution of the reinforced grouting material in the upper layer uneven and affects the construction quality. when microsilica is added into the reinforced grouting material and at the same time a high-efficiency water reducing agent is used to ensure the fluidity of the cement grouting material, the cohesion and water retention of the cement grouting material can be significantly improved by the addition of microsilica.

5. improve the impermeability of reinforced grouting materials with silica fume:

although the total porosity of reinforced grouting materials mixed with silica fume is basically the same as that without doping, the large capillary pores are reduced and the superfine pores are increased, which improves the pore structure of cement and effectively prevents the invasion and corrosion of harmful ions. therefore, the durability of reinforced grouting materials, such as impermeability and chemical corrosion resistance, is significantly improved, and the corrosion resistance of steel is also improved.

select high quality cement according to engineering property. in the water level change, dry-wet alternate or many times freeze-thaw parts of a structure, appropriate uses resistance to sulfate aluminate cement, slag cement, or high alumina cement, or use tricalcium aluminate content less than 6% of portland cement and ordinary portland cement strength grade 42.5, improve the structure design, strength grade, micro microsilica grout material strength grade is generally not lower than c30, improve micro microsilica compaction grouting materials, every m after grouting material of cement dosage is more than 350 kg, orthopaedic use secondary distribution, sand ratio is more than 38% water cement ratio is less than 0.50, mixing water reducing agent and air entrained agent to improve the compactness, to prevent early cold does not have to steam curing and so on.