Experimental Research On The Basic Properties Of High Performance Plastic Concrete

Constrast to traditional impervious materials, plastic concrete has got many excellent properties, making it widely applied in engineering fileds such as cofferdam, dam project, foundation, dam strengthening, etc. Presently, with design standards and structure reliability degree increasing, high performance of plastic concrete is more extreamely urgent than everbefore.In this paper, plastic concrete is added with industrial waste (fibers, fly ash, silica fume, etc.),toughening materials and other admixture in order to make it optimized. The working performance, mechanical properties and impermeability are studied.The main research contents and findings are as follows:1The factors of the type and volume of fiber, content of silica fume and fly ash all have certain influence on the the working performance of the plastic concrete and the influences is obtained by comparation tests.2Based on the mechanical test result of28days age, series of research are conducted on the relative strength, the size effect on compressive and tensile splitting strength and how the factors of the type and volume of fiber, content of silica fume and fly ash influence the performance of plastic concrete. The results indicate that the compressive strength, tensile splitting strength and flextural strength have good statistical relationship. Compared to the150mm cube, the size effect coefficients of the100mm cube related to compressive and tensile splitting strength are respectively0.95and0.85;different fibers reduce differently the strength of plastic concrete; the strength goes upward first and then drops down with silica fume content increasing and decreases with higher fly ash content.3Based on the obtained results of high performance plastic concrete, the elastic modulus calculating method is selected, and how the factors of the type and the voulume of fiber and content of silica fume and fly ash influence the elastic modulus is studied.It is indicated that fibers reduce the elastic modulus; the elastic modulus decreases with higher content of polypropylene fiber and fly ash and increases with higher silica fume content.4Based on the research of anti-permeability, the penetration pressure parameter and the time parameter of the testing about relative penetration coefficient of concrete is analysed, and0.3MPa and6h are suggested; it is indicated that different fibers reduce differently the permeability coefficient, which decreases with silica fume content increasing and first decreases and then increases with fly ash content increasing.5.The evalution method of comprehensive performance of plastic concrete is proposed on the base of studies of working performance, mechanical properties, deformation capacity and anti-permeability, and the comprehensive performance is optimal when plastic concrete is single-doped with40%silica fume.