Study On Making Concrete-cement Based On Mechanochemistry

The concrete materials become the essential, the most main building materials in the house construction and the infrastructure construction by its fine project performance and relatively inexpensive production cost. But there are two problems which are not allowed to neglect in the concrete materials production and the used process, the one is the cement clinker production to natural resource serious consumption and greenhouse gas discharging; the other is to make the waste concrete into the discard. In the grinding process, partial mineral phases in the waste concrete not only become thinner, the specific surface areas increase, but also appear the distortion of crystal lattice and the crystal defects, the surface chemical bonds break, the free energy increase, free radical product even have the crystal indefinite and so on, the mechanochemistry effect, caused the response activity of the grinding material enhanced observably. The article researched on the mechanochemistry effect which was induced in the grinding process for the waste concrete partial mineral phases, systematically opened out the destruction types and characteristics for the waste concrete mineral phases in the grinding process and the grinding condition influenced on mechanochemistry effect, and the purpose that the waste concrete is made into the concrete-cement is analysed and validated.This paper does the following work:(1) Used the laser granularity survey technology, X-ray powder diffraction, scanning electron microscopy (SEM) have the research on the pellet characteristics, the crystal microscopic structure and the surface chemical bonds break and some change rules of quartz and the other mineral phases in the waste concrete under the planet stirrer grinding function.The result indicated that, the planet stirrer grinding function, the quartz mineral phase in the waste concrete has two kind of different destructions forms, brittle destruction and plastic deformation. The brittle destruction mainly made the quartz pellet and the crystal grain become more thinner quickly and the specific surface areas increased, had the machinery activation to the quartz, while the plastic deformation destroys made the crystal lattice distorted, the crystal defects increased, the crystal amorphous strengthened, had the mechanochemical activation to the quartz. Thus the mechanochemistry effect remarkably occurs have to make the grinding accumulated to the certain degree, in other words, the plastic deformation happens. The result indicated that, the planet stirrer grinding function, the other mineral phases in the waste concrete generate solid state reaction, and produce some silicate mineral phases which are regarded reactants.The grindability, burnability and manufacture parameters and performances of concrete-cement are studied further. The results show that all the components in the waste concrete not only have some select grinding process, but also improve the particles thinner, prevent the particles reunited under the help of the grinding aids. The burnability of the waste concrete as cement raw is not good, but it can be improved by adding into the fitting mineralize. And the technical and strength performances of the concrete-cment achieves the 42.5 strength level in the GB175-1999.All the tests prove that the waste concrete as concrete-cement raw is absolutely feasible, so it also show that the recycled using of the waste concrete has a great new prospect.