Research On The Hydration Of Blended Cement Systems At Different Curing Regimes

As a kind of reliable construction material, cement has been a significant part of the modern society. But during the production process, the consumptions of resource and energy are so huge that serious dangers to the environment were made. This project takes full advantage of industrial wastes, and makes it the basic theory of tuning the performance of cement and cement-matrix materials, thus has tremendous scientific significance. In the practical application, areas and climates influence much on the property of industrial materials. This work deals with the effects of protection mechanisms under different temperature conditions on hydration cement-matrix materials, and is of great importance in practical application.The conceptions of equivalent binding water amount and hydration factor were setup, and the calculation model of hydration factor was proposed. Under different cuing regimes, the influence and interaction mechanism of fly ash and coal gangue as the aiding gelation materials on cement hydration were investigated. It was found that under the curing of 60 ℃, the penetration of fly ash and coal gangue stuns the hydration during the first 30 minutes, and then accelerates the process. The dilution effect as a result of the introduction of gelation materials is dominant, while the other hindering effects are secondary. Under standard protection, during the initial 180 minutes, fly ash and coal gangue restrain the hydration, and then promotes it. As time evolves, the promotion becomes stronger. Under the curing of -20 ℃, if dilution effect is excluded, fly ash and coal gangue prompt the hydration.Under different cuing regimes, variation rules of binding water amount of aiding gelation materials and the reaction degree were analyzed, using function of sample hydration extent was determined. The results show that, under the curing of 60 ℃, the hydration reaction and volcano ashes reaction proceed very quickly, but not good for the later hydration. Conversely, during initial stage of hydration, with the proper addition of de-freezers, hydration occurs slowly, influencing little on the later hydration. Low moisture protection constrains the hydration process, and is adversary to volcano ashes reaction of aiding gelation material.Finally, based on the above study, hydration samples under different protections,were analyzed and microscopically tested by XRD, SEM, NMR and so on. It is discovered that the introduction of coal gangue obviously improve the pore structure of cement mortar, and increase micro pores while reduce large holes. With the increase of protection temperature, large holes (>50nm) remarkably increase and micro pores diminish. Minus temperature protection is opposite, with the micro pores increasing. Under high temperature protection, a large amount of sol is inorganic, scattered, holes and capillary porosity form on the interface between non-hydrated particles and sol, thus the interface transition area is weakened, and does no good to the strength during later stage.