Research On The Properties Of Modified Glass Fiber And Polypropylene Fiber Reinforced Concrete After High Temperature

The occurrence of fire will not only destroy buildings, and will cause harm to people’s life and property safety, high temperature performance of concrete is an important basis for concrete structure design, the traditional low tensile strength of concrete materials, brittle deformation defects liable to happen, can be fatal in the fire safety hidden trouble, fiber mixed with internal microstructure changed the traditional concrete, if this change makes the high temperature resistant performance of concrete is enhanced, can improve the fire safety of buildings. Therefore, the study has important theoretical and application value.Based on the modified glass fiber and polypropylene fiber concrete as the research object, use after different cooling load, explore fiber concrete after high temperature mechanical properties change rule; Through the observation of the concrete macroscopic phenomenon, explore blowout performance of fiber reinforced concrete; Accordingly, microscopic test with theoretical explanation fiber on the properties of concrete crack. Main conclusions are as follows:The incorporation of polypropylene fiber can improve the compressive strength of concrete, but the improvement is not obvious at room temperature, and it has no obvious improvement to the tensile strength and flexural strength.. Addition of glass fiber concrete, the compressive strength of concrete improvement effect is not obvious, but whether it is at room temperature or high temperature, to the concrete splitting tensile strength to improve; for the flexural strength, the improvement effect of the glass fiber at room temperature and inconspicuously, only in the 800 DEG C improved slightly.After high temperature, the mixed polypropylene fiber can improve compressive strength of concrete, but temperature effect is not obvious. Join d fiber concrete, both room temperature and after high temperature, splitting tensile strength of concrete are improved effect; For flexural strength, improve the function when the room temperature is not obvious, only a slight at 800℃.Cooling of concrete after high temperature strength has a certain impact, spray cooling instantaneous temperature difference obvious, the function of temperature stress of concrete made of concrete under the condition of water cooling injury is more serious than under the condition of natural cooling. Above 600℃, water cooling on the damage of concrete co., LTD. With the increase of incubation time, improve the compressive strength of concrete, and the effect increased with the temperature ascension is more apparent.Whether it’s mixed with polypropylene fiber or adding has not been modified fiber glass fiber concrete occurrence blowout phenomenon, through the vapor pressure principle, in the concrete mixed with polypropylene fiber and modification of the glass fiber can enhance the crack resistance of concrete.In this paper, based on the existing experimental data fitting out of the mechanical properties of concrete after high temperature and heating temperature, the relation between according to fitting formula and the corresponding parameters can predict the residual strength of concrete after high temperature, the research of concrete after high temperature fire damage analysis has certain reference significance.