Micro-silica powder has brought more or less benefits to various industries since it was discovered and utilized.It not only reduces the difficulty of work,improves work efficiency,but also saves a lot of costs,but the use of micro-silica powder requires attention.
The first is the amount of addition,generally in the cemented material should be added in the amount of 5-10%.The addition method of silica fume is divided into internal doping and external doping.What is internal blending?That is,in the case of the same amount of water,a micro-silica powder can replace 3-5 parts of cement,and can maintain the compressive strength of the concrete while significantly improving the main performance and other properties of the concrete.The external mixing means that the amount of the cement material is constant,and when the silica fume is added,the strength of the concrete strength is remarkably improved,and other properties are relatively improved.When micro-silica powder is added to concrete,there will be some slumping and some loss.As for this,it is enough to pay more attention than the test.Micro-silica powder works best with water-reducing agent.It is recommended to mix fly ash and ground slag to improve the construction effect.
In accordance with the work in strict accordance with the cooperation,the castable of micro-silica concrete must be tested by the laboratory,and then the corresponding construction ratio is made.During the mixing of the silica fume concrete,the microsilica should be added to the mixer immediately after the aggregate is charged.
In the construction method,there is basically no difference between the construction method of silica fume concrete and ordinary concrete,but it is necessary to organize well and vibrate densely during the construction process.The early strength of the silica fume concrete will make the final setting time advance,and should pay attention when the surface is wiped;at the same time,the addition of silica fume will increase the viscosity of the concrete and greatly reduce the bleeding,making the surface slightly difficult.
In terms of construction safety,the construction safety of silica fume concrete should be strictly in accordance with the relevant national construction specifications of concrete engineering.However,due to the lighter silica fume,it is strictly forbidden to throw materials at high altitude to prevent the flying of silica fume.