Chloride Diffusion In Nano-concrete Under The Effects Of Scouring And Loading

Nano-concrete is getting increasing attention for its advantage in durability.Previously studies on the durability of nano-concrete were focus on its performanceunder an environmental factor. However, during the serving period of the concretestructures, they are generally under the coupled effects of enviornmental factors andloading. Therefore, this work intent to investigate the performance of nano-concreteunder coupled effects of scouring, loading and chloride avasion.1) Advantage of nano-concrete in resisting the coupled effects of chloride diffusionand scouring with respect to pure concrete was studied. Firstly, it was found thatchloride diffusion and scouring could accelerate the progression of each other. A quickeringression of chloride caused by the scouring resulted moving of exposed surface wasexperimental and theoretical evidenced. Concrete containing1%Nano-TiO2in theweight of cement, having simultaneously the good pervasion and abrasion resistingproperty, was studied in this paper and showed a better performance in resisting thecoupled effects of chloride diffusion and scouring compared to pure concrete.2) Compared with the normal concrete, nano-concrete has the advantages inresisting propogation of crack and more compactive transition zone. The effects ofaggregate size, transition zone thickness and cracking state on the chloride diffusionhave been experimental studied. The mechanism of the advantage of nano-concrete inresisting chloride diffusion was investageted based on the experimental and theoreticalresults.3) The chloride diffusion in nano-concrete and normal concrete under the coupledeffect of flexural loading was experimental studied. A concrete beam was fabricated andapplied with flexural load. The chloride contents at various locations in the flexuralbeam were measured to give a profile of the chloride. The chloride content in the tensilezone in the concrete beam was found to be higher than that in the compressive zone.4) Based on the Fick’s second law and monte carlo method to generate randomaggregate, study of numerical simulation of chloride diffusion in concrete by ANSYS.The diffusion coefficient of chloride ion was calculated by numerical simulation andcompared with the experiment, and studies by simulate of the influence of diffusiontime、interface characteristics、aggregate size、scour action and cracks and other factorson the law of chloride diffusion, and the results were compared with the experimentalfindings.