Experimental Research And Engineering Application Of High Performance Concrete

HPC(High Performance Concrete, HPC)is a kind of new concept concrete based on the durability of concrete structures. Different from the traditional concrete, HPC is considered as the most comprehensive performance concrete of the world till now,for its excellent characteristics:strong durability,good working operation, high intensity and excellent volume stability.This dissertation traced the developed process and recnt situation,discussed the recent and future trend of concrete. The main trend of concrete technology is high strength,high performance, green high technology and complex in a recent period of time. Definition, composite, microstructure,technical method, curing and mechanic characteristic, durability mixing proportion design and mixing technology of HPC was simply depicted. Through the research mainly on different preparation and deployments of the HPC's raw materials, such as concrete admixtures, mineral admixture and so on, this paper tries to get the rules that how the properties of HPC and hardened concrete are affected by these raw materials. Meanwhile, the paper tries to conclude the optimal ratios of raw materials for concrete of different properties.Firstly,it is revealed that the admixture technology plays a key role in high performance concrete, through the test of incorporating a variety of concrete admixtures into the concrete. Admixture, in particular functional admixture, can improve the construction properties, mechanical characteristics, deformation properties, durability and thermal properties, through which the concrete's high performance can be realized. With different environments and actual situations, admixture of different functions can meet the various performance requirements of high-performance concrete, and make the diversification of concrete realized.Secondly, it is revealed that the mineral admixture technology plays a key role in high-performance concrete, through the test of incorporating a variety of mineral admixtures into the concrete. After incorporating the admixture, the composition and structure of concrete hydrate are changed. The mineral admixture makes great contributions to all properties of the concrete. However, with too much amount of mineral admixture, it will have a negative effect on mechanical properties and durabilities of concrete. Therefore, it is necessary for US to have a correct understanding and application to mineral admixture, and to adopt the right mineral admixture technology. Just through this way,can mineral admixture's positive effect on HPC be realized, and may the HPC'S cost decrease as well.Finally, curing is one of the most important procedures in concrete construction practices,especially for high-performance concrete.However,the evaluation approach of the curing efficiency is seldom at present,so it is difficult to determine the efficiency of concrete cured on site.That makes the curing in the construction often be neglected,which affects the performance of concrete,especially the durability.Therefore,the research on the evaluation approach of the curing efficiency is necessary.