The Research For The Influence Of Freezing-thawing On Fly Ash Concrete Carbonization Performance

The study on the durability of concrete structures for the single factor effect of thecarbonation and freeze-thaw, domestic and overseas scholars have made many researchresults, which has been widely used in engineering practice and got an application.However, the actual concrete structure is not in a single factor, carbonation or freeze-thaw, but subjected to the coupling effect of a variety of factors. At present manyfactors under the coupled action of the durability of the concrete study is less, but thereal project of concrete carbonation freeze-thaw role of the acceleration caused bycorrosion in advance to steel structure to the problem of shortage of durability isobjective existence, so the concrete undergo both common mechanism of the effects andfreeze-thaw effects on the concrete carbonation performance of the influence law studyis very necessary.This paper carried out the carbonization test, freeze-thaw cycles and carbonizationunder the combined action of the durability of concrete test, study the same water-binder ratio under different the fly ash content in carbon dioxide under the action ofconcrete carbonation depth, the fly ash content analysis of the influence of concretecarbonation depth. Study the same water-binder ratio under different the fly ash contentin natural freeze-thaw cycle through concrete and carbonization both common role ofconcrete structure endurance decay laws, and freeze-thaw cycle under the action ofconcrete neuter law of development.According to the test results, data analysis and theoretical analysis of concreteneuter development under the freeze-thaw cycles, it studied the different neuter depthsof concrete suffered between carbonation and combined action of both, analyzed thefunction of concrete carbonation depth in freeze-thaw cycles, and analyzed the damageprocess and damage law of concrete in freeze-thaw cycles and the development rules ofconcrete carbonation depth in freeze-thaw. Getting the influence coefficient of concretecarbonation with freeze-thaw and laying the foundation for the prediction model ofconcrete carbonation depth under freeze-thaw.In this paper, a comprehensive analysis of a variety of factors affect concrete,consider the concrete structure is based on the freeze-thaw cycle, ambient temperature,humidity, atmospheric carbon dioxide concentration and the nature of the material of the concrete itself, the water-cement ratio can be carbonized material content ofsimulation analysis,analysis of freeze-thaw cycle under the law of development ofconcrete porosity, concrete carbonation mechanism on the basis of the combination ofgas diffusion mechanism in the concrete, drawn through the experimental data theeffective diffusion coefficient of carbon dioxide in the concrete under freeze-thaw cycle,andthe eventual establishment of a freeze-thaw cycle under concrete carbonation depthprediction model that the effect of freeze-thaw cycle durability of concrete structuresdesign and life prediction is of great theoretical significance and application value.