The Study On The Influence On Carbonization Speed Of Concrete By Wind

The durability of concrete structure is one of the focus studieds in the civil engineering field. Carbonation is the main cause for the durability failure of concrete structure in the atmosphere circumstances .Concrete carbonization can be accelerated by wind pressure, which causes the different durability in the section of concrete strcture. Therefore research into this problem is necessary in order to design more enduring concrete sections. Supported by National Science Foundation ,new researches have been made in this dissertation as follows.the flow of carbon dioxide(CO₂) in concrete is a process of filter ,which follows Darcy'Law and convection mass. The p-x-t relationship is established based on the calculating model of concrete carbonization accelerated by wind pressure, and the carbonaization depth is calculated in exmples. A Simple way is provided to calculate the concrete carbonaization depth.In order to validate the effect of concrete carbonization accelerated by wind ,three groups of concrete beam carbonization experiment with different sections respectively (rectangle,Ttype and â…¡ type ) were analysed. Based on the theoretical analyses and experimental results, it is concluded that the wind swirl and the fosse moat effect can also accelerate the concrete carbonization. The principle of concrete carbonization accelerated by wind pressure is perfectedBased on analysis of the influencing factors of concrete carbonation. probability models of carbonization speed coefficient are established according to the measurement data in projects and test date in laboratory. They all consist with normal probability model. And a stochastic process model of carbonization depth is established, which searves to provide a reliable way for the prediction of carbonization depth.Based on the measurement data in projects and test date in laboratory, method for equal durability design of concrete bridge sections under theinfluence of wind pressure is advised . The preliminary work is finished to establish the equal durability design method of concrete structure section.