Study On Cement Fineness Features Based On The Durability Of Road Concrete

With the develop of the cement concrete road there are many problems about concrete durability, as one of important raw material of the cement concrete pavement cement has a great impact on the durability of concrete. And its influence is mainly manifested in the following areas: (1) the mineral composition of cement; (2)the fineness of cement(specific surface area and particle size distribution); (3)the content of SO3 and CaO; (4)the content of alkali; (5)the mixture materials; (6)the type of cement.At home and abroad on the status and background of the project, this research has in-depth analyzed the influence of cement technical nature on the performance of road concrete, which contains standard consistency water requirement, cement setting time, cement pellet group characteristic (specific surface area, particle size distribution), chemical composition, strength, deformation and durability, and defines the roles played by these technical nature. By the interior experiment and theoretical analysis, it studies the influence of cement specific surface area on the various properties of cement; analyzes the impact of cement chemistry composition and mixture materials on cement quality; makes use of Mastersizer2000 laser particle size analyzer to measure cement particles, applies the theory of gray system, focuses on the influence of particle size distribution of cement on cement performance, defines the correlation between particle size distribution and cement performance, and recommends cement technical indicators.From the influence of cement particle size distribution on cement properties, it can see that 30μm particle is cut-off point where particles play advantage or disadvantage role; critical limit particles (<30μm particles), the key range of particles (3～30μm particles), characteristic parameter and distribution coefficients, which have good correlation with the cement properties, so called particle size distribution of cement-based cement technical indicators. The way optimizing cement quality as follows: to improve the content of silicate mineral and C3S mineral in cement clinker, the adjustment of C3A and C4AF content according to the standards of Road cement, the selection of active mixture materials, choosing efficient and low consumption roller mill grinding method, rational use of aids.