Study On Preparation Of Vaterite CaCO₃ Effect On Green Concrete Performance Of Gas-liquid Method

Portland cement concrete is the most widely used building materials in the world, the world’s second only to water,70% of the total amount of building materials. Although it is easy to use, easy to use, and other advantages, but the production of ordinary portland cement is to release a large number of CO2, so that global warming, exacerbated by the "greenhouse effect"". So according to the carbon emissions of the concrete in the vast majority are from ordinary portland cement, in order to cope with global climate change can by reducing the amount of concrete in ordinary portland cement is one of the most effective way.In this paper, the main research contents and results are as follows:1, the tried a variety of methods to test, to seek a higher price method of preparation of spherical vaterite calcium carbonate, calcium chloride and carbon dioxide-weak buffer (the flow rate of carbon dioxide for 2 L/min) method to prepare spherical vaterite calcium carbonate crystal, for large-scale production for green concrete manufacturing replacing part of the cement.2, the preparation of three kinds of schemes, the calcium carbonate does not isomorphous with different proportion of mixed into concrete replace part of cement, calcium carbonate and fly ash together with different proportion of mixed into concrete replacing part of the cement, different ratios of calcium carbonate and metakaolin together incorporation into mixed concrete.3, from the compressive strength test results found that in the concrete mixed with different proportion of calcium carbonate, water cement ratio of 0.43, the situation of this group of tests to a certain extent reflects a certain degree of law. We can draw a conclusion that in concrete mixed with a certain amount of vaterite is can increase the compressive strength, the amount and the incorporation of is the requirements. Which will help us to know the incorporation in the concrete goal doped aragonite type calcium carbonate is the existence of an optimal amount, from the point of view of this study, the estimated should be between 2%and 5%.4, through the scan electron microscope (SEM) and X ray diffraction test analysis, the research and production of vaterite calcium carbonate although micron particle size, from X-ray maps can also obtained by calculating the overall activity could reach 95.8%.5, from the SEM images, see not adding vaterite cement mortar paste submicroscopic organization structure has more pores and cracks, structure is loose, the cement paste mixed with vaterite can see that submicroscopic organization structure in the pores and cracks decreases obviously, and the structure is more compact.