The durability of concrete 英文版混凝土论文.docVIP

The durability of concrete In civil engineering, concrete is the most widely used and the amount of one of the largest building materials. Over the past century, the concrete strength to continuously improve its main development trends. Chinas large population, the urgent need for housing.Structural Design not only to meet the requirements of safe and reliable indicators, but also consider the durability requirements. The durability of concrete issues, refers to the structure in the environment and cause long-term evolution of the structure due to internal or external reasons, the concrete has to lose the ability to use. That for durability failure, the durability of many reasons, have antifreeze failure, failure of alkali - aggregate reaction, chemical corrosion failure. Part of the concrete structure in the environment below freezing, water in the pores will freeze, resulting in volume expansion of cold water migration, the formation of various pressures, when the pressure reaches a certain level, resulting in the destruction of the concrete.Alkali - aggregate reaction of concrete chemical reactions that occur by the active component of the alkali in the concrete aggregates, causing the expansion of the concrete, cracking, or even destroy. Response factors in the concrete, and its harmful effects are often not the root of the rule is a big hidden in the concrete works. Concrete structures in aggressive media environment, will cause the cement paste to a series of chemical, physical, and materialized change gradually been eroded, cement strength to reduce serious, as well as destruction. In concrete engineering in order to meet the requirements of concrete construction work, that is, water consumption, water-cement ratio is high, resulting in high porosity of the concrete, durability reduce. Also, the lack of hydrate stability in the cement paste will have an impact on the durability.