Study And Application Of The Concrete Structures Repairing Material

Since the establishment of the PRC, plenty of concrete projects and buildings were newly constructed. Because of many years'chemical, physical and biological interacting effect, and the relatively lower standard of project, many projects see aging as well as disease phenomena in different degrees, which make it impossible to make use of such projects untill the deadline of the initial designed working life, and hence bring great economic losses. Among them, the aging and disease of armoured concrete problem is the most serious one.At the time being, most developed countries are concentrating the construction focus on maintaining, rebuilding of the old buildings as well as putting up new buildings so as to create more investing gains. In China, the state situation and the strategy of sustainable development make it consequential to stress on continuation and rebuilding of old buildings rather than on merely founding new buildings. Actually, statistic evidence indicates that, compared to building a new project, rebuilding will save 40% the investing cost, 50% of the project time, and only needs 1/3 ~ 1/4 of the time to take back the investment fund. At the time being, 20%~30% of China's buildings can be rebuilt. Rebuilding projects not only saves much investment fund but also saves much land, which will certainly contribute greatly to solve the problem of city land-lacking problem.This thesis makes analysis of the structure recovering and reinforcing of the hyperbolic cooling tower. According to the project characteristics, the author firstly tried to find out the proper repairing material, which was obtained by adding some MA cement modifying agent as well as silicon ash into common concrete. The proper formulation of the concrete was finally obtained after many times'testing. And the modified concrete basing on such formulation meets the requirements in terms of both intension and durability.Basing on tests of primary mechanics and durability of the composite modified concrete, the author finds that by adding 18% MA cement modifying agent as well as 6% silicon ash, the modified concrete obtained would be of very high felt intension and good durability.Then, the proper qualified modified concrete was applied in rebuilding and reinforcing of the cooling tower. From the structure calculating point of view, the data obtained by making use of the ANSYS software indicates that intension of the original structure of the cooling tower cannot meet the carrying capacity requirement, and proper reinforcing measures must be taken for safe usage. Then this thesis gives the suggestions of reinforcing and after calculating and checking, the carrying capacity after reinforcing can meet current regulations finally. From the durability pint of view, after researching the life-span of the cooling tower, the author concludes that it would be wider of the carbonized wall than of the steel's protective film, if only the cooling will be used 10 years further. The author researches the life-span of the reinforced cooling tower by using the accelerating test method, and concludes that anti-carbonizing ability would be improved greatly by using modified concrete as the repairing material, and hence can well meet the well-balanced requirements during the designed project working life.