The experimental research on the effect of different incorporation of granite powders on the workability, mechanical property and impermeability performance of concrete is carried out. The result show that the concrete with an appropriate dosage of granite powder exhibits favorable workability, impermeability performance and cohesiveness. And granite powders agree with cement-based materials. Within some dosage of granite powders, the compressive strength of the mixture is approximate to that of common concrete. When the 10% of cement was replaced by the granite powder, good impermeability performance exhibits, with the relative permeability coefficient 30% lower than that of common concrete.

large amount of granite powders wastages were produced during the process of the stone processing, therefore the research on recycling and utilizing the wastages was carried out. Based on the size distribution of granite powders specified by the laser particle size analyzer, the research on the influence of granite stone powder on the mechanical properties of cement mortar was carried out through the cement grinding test and scanning electron microscopy (SEM). The test result shows as follows. The flexural and compressive strength of cement mortar with replacement rate of granite stone powders of 20% is the highest when the same particle size of granite stone powder is incorporated. When the replacement rate of granite powders is the same, the smaller the particle size of granite stone powder is, the higher the flexural and compressive strength of cement mortar is. When the replacement rate of granite powders is 20%, with the particle size ranging from 0μm to 45μm, the filling effect of the granite stone powder can be fully utilized to the best.

The influence of an alkali-free concrete hardening accelerator on the performance of the concrete was studied, the hydration heat and the rate of the hydration heat the corresponding cement with and without the accelerator addition were tested by the calorimeter, the hydrates of them were analyzed by X-ray diffraction (XRD), and the acclerating mechanisms were analysied in this paper. The results show that the compression strength of the tested concrete (with the accelerator addition) have be enhanced repectively by 43%, 47%, 39% and 31% at the age of 1days, 3days, 7days and 28days compared with those of the controlled concrete (without accelerator addition), the hydration rate and the amount of the hydrates of cement with the accelerator have also be increased significantly at different hydration time. The reason for causing the above results is because of the role played by Calcium formate, Crystal embryo and Ferric sulfate together.

Silicon nitride nanowires have been synthesized by mechanosynthesis method. The silicon powders were first milled for 160 hours under the presence of ammonia gas with 300kPa. And then they were heat-treated at 1250 for 2 hours in the pure nitrogen gas. The phase and the microstructure of the as-prepared product were detected by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results showed that the product consisted of α-Si3N4 nanowires. The nanowires had the length of tens of millimeters and the diameters of 50～100nm. The vapor-solid (VS) mechanism was employed to interpret the nanowires growth.

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