Study On Cement Particle Characteristics Based On The Durability Of Road Concrete

With the rapid development of the cement concrete pavement, its durability issue is increasingly appearance, as the main raw material of the cement concrete, the quality characteristics of cement has a great impact on the durability of concrete. And its influence is mainly manifested in the following areas:(1)the fineness of cement(specific surface area and particle size distribution);(2)the standard consistency water requirement and setting time;(3)the strength grade of content;(4)magnesium oxide and sulfur trioxide content of the cement;(5)the mineral composition of cement; (6) cement variety.In this paper,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 strength standard, cement pellet group characteristic (specific surface area, particle size distribution),chemical composition, consistency water requirement, cement setting time, antifreeze, anti-sulfate erosion,shrinkage and so on. This paper is divided road durability into dynam resistance and weathering resistence, dynam resistance refers to the mechanical effect on the concrete pavement, and weathering resistence refers to the climate effect on the concrete pavement. By the interior cement which comes from different regions mortar experiment and theoretical analysis, it compares the chemical and physical properties of the cement; and find the factors which affect the road concrete durability; 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 makes use of concert experiment to validate the conclusion, finally 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 value x and distribution parameters value x*n, which have good correlation with the cement properties, so called particle size distribution of cement-based cement technical indicators. According to the standards of Road cement, improve the content of silicate mineral and C3S mineral in cement clinker, and adjust C3A and C4AF content,.inorder to ensure the cement quality.