Research Of High Performance Concrete With Low Cement Content

The research of how to improve the durability of normal concrete has becomemore important when extensive attention caused by the problem of durability. Many project examples show us the concrete that had an adequate 28-day compressive strength but deteriorated in the early stage of the life cycle because they were facing an environment for which they were not conceived or because they were not placed or cured correctly. High performance concrete (HPC) is new high-tech concrete, which is on the basis of improving of the property and aimed at the durability design.At the same time, HPC can reduce the cement content per cube and use more mineral additives. So it provides a new solution to the environment protect and sustainable development.On the basis of experiment, the paper shows us the research of the mixture, mechanics and durability of HPC. Results demonstrated that a good quality HPC with adequate 28-day compressive strength could be achieved by partially replaced cement with ground mineral additives and the use of superplasfics. It is realized that with the increase of mineral additives content the strength coefficient of cement and the contribution of pozzuolana effects to the concrete by the mineral additives is obviously increased. The long-term strength development of the HPC is superior to the normal concrete. As far as the durability concerned, the resistance of sulfate attacks of the normal concrete couldn't compared with the HPC. With the addition of the mineral additives, the structure of the cement paste can be improved and the resistance of sulfate attacks can be advanced. On the basis of environmental investigation, it is founds that the acid rain could be one of the key factors associate with the deterioration of concrete in large city due to atmospheric pollution. Acid rain may possibly cause the double harm for the sulfuric attack and the sulfate attack.Concrete with the addition of ground blast furnace slag and limestone can improve the resistance of sulfuric attack effectively. It is also approved by the results of the XRD. According to the code of durability test for normal concrete, the results show that the resistance of carbonate to the nonnal concrete is superior to the HPC. However, the quality evaluation to the HPC and the normal concrete is different, the results of the resistance of carbonate to the HPC should be given more consideration. Moreover, the autogenous shrinkage and the possibility of cracking in the early stage of the HPC also can be controlled, with the addition of the mineral additives.