what are the advantages of adding microsilica to concrete?-pg电玩城

   engineering practice shows that it is the key to micro-silica powder concrete construction to control microsilica concrete cracks. for this reason, the maintenance of microsilica concrete is earlier than ordinary concrete. before the concrete is poured, it must be sprayed to reduce the evaporation of water or covered with plastic film or sprayed with concrete curing agent to keep the concrete surface moist, but it is not suitable for water flow and visible water droplets: after the concrete is finally set, it should continue to cover. plastic film or spray curing agent or cover the surface of the wet grass bag and sprinkle water to keep the concrete in a wet state, the curing time should be no less than 28d. lin baoyu and wu shaozhang of nanjing hydraulic research institute have studied measures to reduce plastic cracking and early shrinkage of silica fume concrete, including extending concrete tide.

    admixture for concrete: mineral admixture, mainly blast furnace slag in smelting non-ferrous metal industrial by-products, phosphorus slag as a by-product of phosphating industry, fly ash discharged from thermal power plants and boiler slag in chemical industry, and natural silica fume, zeolite, kaolin and limestone.

   the first advantage: reduce the water demand of concrete, improve concrete pumping performance, improve concrete compactness, fluidity and plasticity, reduce bleeding and segregation, reduce concrete slump loss, prolong concrete setting time, slow down hydration rate and reduce the advantages of hydration and heat release.

   the second advantage: improve the compactness of concrete slurry structure, improve concrete pore structure, anti-seepage and freeze-thaw resistance; resist erosion of fresh water and sulfate medium; effectively prevent chloride ion diffusion, have good protection; prevent and inhibit alkali-aggregate reaction; general concrete strength growth rate in the late stage can improve the durability of concrete.

   this kind of concrete with microsilica admixture is mainly used for large-volume concrete engineering, underground engineering, seaport engineering, road and bridge engineering. the application of microsilica as a blending agent in the concrete industry is an area in which the research on the comprehensive utilization of microsilica is relatively early, with many achievements and wide application. since the microsilica has physical and chemical characteristics such as fine particles, large specific surface area, high purity of sio2, and strong volcanic ash activity, the addition of microsilica as a blending agent improves the performance of various aspects of concrete. such as significantly improving the adhesion and cohesiveness of plastic concrete, greatly reducing the amount of springback, increasing the thickness of shotcrete once formed, shortening the construction period and saving engineering cost.