Cement-Based Composite Properties Under The Effects Of Scouring And Chloride Ion Erosion

Durability is one of core issues in the field of civil engineering and an important consideration for determining the length of normal service life of concrete structures,especially for hydraulic concrete structures serving in harsh environments,which face many environmental factors destructively such as erosion and ion erosion,such as bridge piers,port terminals,and concrete structures which locate the position of rivers and lakea with much sediment.My subject is based on the background of China's offshore environment,focusing on the damage characteristics of hydraulic concrete surface after the action of chloride ion erosion and sediment erosion.This paper has focusd on the following aspects.1)The anti-scouring performance of different water-cement ratio hydraulic concrete has been studied.The multi-dimensional characterization methods such as mass loss,aggregate area ratio and surface flatness have been used to visualize and numericalize compressively the erosion process and surface topography evolution of hydraulic concrete;In addition,the variation characteristics of the erosion failure rate and the evolution law of the concrete surface characteristics of the hydraulic concrete during service are obtained,and the erosion period has been divided according to the change of the erosion characteristics of the concrete surface.2)The ball milling method has been utilized to improve the dispersion of fibers and nanomaterials in the cementitious material.The anti-scouring properties of concrete with different water-cement ratios of fiber and nano-materials are studied by compressive strength and particle size analysis of abrasives,analyzing the mechanism of scouring liquid suspension on concrete erosion successfully.Besides,the improvement characteristics and regularity of scouring fibers and nano-materials on the erosion resistance of concrete have been obtained,which determines the optimum dosage of nano-materials in concrete.3)The diffusion law of chloride ion in different water-cement ratio concrete is studied,and the paper has analyzed compressively chloride ion diffusion coefficient combined with concrete pore structure characteristics.In addition,The influence characteristics and mechanism of chloride ion erosion on the erosion resistance of concrete are studied by writer.The diffusion of chloride ion in concrete has been numerically simulated by COMSOL,confirming the experimental diffusion results of chloride ion of the experiments.What's more,the normal service lifes of different water-cement ratio concrete in China's offshore waters are predicted.