Research On Preparation, Structure And Performance Of Ultra High Strength High Performance Concrete

The fast growing national economy and the rapid societal development have dramatically increased the scale of construction and their investment. At the same time , the ever -growing population , the resources shortage, and the daunting environmental pollution have made high rises, skyscrapers a trend. More over, concrete structures have become widely demanded in severe environments such as off--shore petrol platform, cross strait bridge, under sea tunnels, drainage pipes, nuclear waste containers, nuclear reaction shells, poisonous chemical containers etc.. All of the above mentioned buildings and structures require the use of cement based materials. Since the performance of these projects is highly stressed, they must have high strength, high durability and a high stability of size. More than that, their construction also requires a high fluidity of cement concrete. Unfortunately, the traditional cement and concrete technology is inadequate to meet that demand. The technological development of cement based materials and the urgent need to meet the demand of concrete engineering have made cement based materials to take up the direction of high performance.High performance cement based materials means high strength, excellent durability and super size stability. According to that criteria , high performance cement based materials should include: Micro-defect-Free Cement(MDF), Densified System Containing Homogenously Arranged Ultra fine Particles(DSP), Reactive Powder Concrete(RPC) and so on.Viewing solely from their performance, MDF, DSP, RPC all enjoy a high compressive strength. Their flexural strength, fracture toughness and elastic module have broken the limit of traditional cement based materials. All these materials have acquired the features of high toughness material. However, to produce these materials requires selected raw material, complicated technical procedures, which make it too costly to meet the demand of project engineering.Therefore, it is of great significance to find the right way of preparing ultra-high strength high performance concrete with present cement concrete technology and conventional material and common technical procedures.This dissertation is aimed at the following researches:...