how does microsilica silica fume improve the performance of concrete-pg电玩城

microsilicar concrete used in water resources and hydropower engineering, can improve the abrasion resistance of engineering at home and abroad the traditional abrasion resistant materials multi-purpose polymer materials such as epoxy mortar, this kind of material abrasion resistance is good, but due to its linear expansion coefficient of several times the ordinary concrete base, and basement concrete temperature adaptation is not good, easy to fall off, craze in natural climate conditions and the construction of complex, toxic and expensive, not widespread popularization and application. with the use of microsilicaconcrete, the abrasion resistance of the concrete can be doubled, and the abrasion resistance of the concrete at the speed of 48m/s can be increased by more than 3 times.

(1) improve the early and final strength of concrete

when microsilicar to replace rate was less than 30% of cement, the steam temperature is 80 ℃, the compressive strength of mortar day for 2 times, don't mixed microsilicar (100 mpa); in the absence of autoclave curing, it is almost 3 times (150mpa). with standard curing, the compressive strength of mortar is improved obviously. when micromicrosilica is used in combination with high-efficient alkali water agent, the water-binder ratio (w/c si) of concrete can be reduced to 0.13-0.18. the cement particles are filled with microsilica and the compressive strength of concrete is 3-5 times of that without microsilica.

(2) increase the density of concrete

the addition of microsilica into concrete increased the silicon content of the reaction, and the crystal growth was observed in the voids of cement stone mixed with silica concrete under electron microscope. in addition, the microsilica particles are very small and evenly filled with concrete micro-holes. the micropore volume of concrete cement with microsilica is obviously reduced no matter the curing condition.

(3) improve concrete segregation and bleeding performance

after pouring concrete, water is often separated from the concrete, that is, water film is formed on the surface layer, also known as floating slurry, which makes the upper concrete distribution uneven and affects the construction quality. foreign studies have shown that the more si/ (si c), the more difficult it is to isolate and bleed concrete. when the replacement rate is up to 15%, concrete slump, even if it is up to 15-20cm, hardly produces segregation and bleeding. when the replacement rate is up to 20-30%, the concrete should not be isolated directly into tap water. because of the improvement of concrete segregation and bleeding performance, the concrete with silica powder can be used as an underwater project such as harbor and tunnel.

microsilica is very active and has water reducing property. it is suitable for the admixture of early strength and high strength concrete needed for rapid construction. the admixture of high-strength shotcrete used for supporting in the construction of tunnels, subways and large foundation pit structures; admixture of concrete used in underwater construction projects (e.g. piers, dams, drilling platforms, etc.)