The Research On The Steel Fiber’s Capability Of Preventing Commercial Concrete Slab Floor From Cracking

Increasing concrete floor crack of Cast-in place Commodity has become a common problem which exists in current engineering. According to the investigation, concrete shrinkage deformation causes more than70%commercial concrete floor cracks currently. It is mainly because commodity concrete is made up with a lot of cement, water, sand but a little gravel, with the features of liquidity and slump, and uses some additive. When it’s constructed in the environment of high hydration heat, high temperature, high wind speed and relatively low humidity, the surface filtration speed of Cast-in-place Commodity becoming fast, make commercial concrete shrinkage become too big. When the tensile strength and ultimate tensile is less than concrete’s shrinkage deformation, concrete shrinkage deformation will develop into cracks.In order to prevent commercial concrete floor cracks from teeming, this paper will introduce the application of steel fiber in commercial concrete floor to solve the problem of cracks, and analyze the regular pattern of concrete contraction with different proportion of each specimen. And make simulation floor of concrete commodity mixed with steel fiber, observing the early crack development of specimens in the condition of actually maintenance through the method of statically determinate loading, and do cracking test for each group of simulated floor respectively to test the effect of control ability of commercial concrete simulation floor with steel fiber of different dosage from cracking. Meanwhile analyzed the crack width of steel fiber with different volume proportion in the circumstance of hierarchical load cases by using SPASS statistical analysis software, and made a comparison between mean value of each floor slab specimens measured results and crack formula calculated value in specification of both home and abroad, and analyzed the causes for different results and the crack formula differences between domestic and foreign area.Finally, through the related test and analysis result, and the comparison of formula between both home and abroad, this thesis identified the best volume dosage of.steel fiber in inhibiting commodity concrete floor from cracking.