Chinese Environmental Zonation Based On Durability Of Concrete Structure

Durability environmental zonation is carried out accoding to the influence which environmental conditions, including ambient temperature, relative humidity, chloride ion concentration, carbon dioxide concentration, freeze-thaw cycles, work on concrete structures, and it is also taken into a comprehensive consideration of the structural importance, structural service conditions, structural style and other factors. The country is divided into different areas according to the degree of risk, it is expressed in the form of graphics, and it also gives the determitive material and detailing requirements.The purpose of durability environmental zonation is to reflect and comprehend the durability environmental differences in different regions, and it also gives guidance for the durability design of concrete structures.The main purpose of this paper is to complete durability environmental zonation. In this paper, three main failure mechanisms in the durability theory of concrete structures, carbon destruction, chloride ion penetration and the freeze-thaw damage, is seriously discussed. According to the analysis, the main environmental factors which play an important role in the durability environmental zonation are determined as the environmental indictors. At the same time, based on the research of the laborary and field testing, there are three main mathematical expressions which depict the durability deterioration mechanisms of concrete structures are adopted or proposed, and the limit state equation of the three deterioration mechanisms is anlysized. Taking into account the uncertainty in the service life prediction of concrete structures, numerical method based on Monte Carlo method is carried out to predicte the service life of concrete structures in different regions, and the statistical chrtacteristics of the main parameters also is analyzed. Then the life prediction values of different regions can representate the influence degree which environment impact on the durability of concrete structures.One city is selected as the benchmark to determine the relative damage value of different regions, and it is used to complete the Chinese environmental zonation map on durability of concrete structures and durability enbitonmental zonation standard.