The Research On High Performance Concrete With High Volume Fly-ash

Mechanical properties and durability of high volume fly ash concrete which contains 40 to 70 percent of fly ash by weight are studied here by using the process of HPC technique. It existed a conservative attitude of the volume and the infection of fly ash in concrete. That's because of anxious seat and technical hindrance. Technical Specification for High Performance Concrete provides detailed rules on the additive fly ash quantity which is less than 30% in cementing material. With the application of the technique of HPC, the additive fly ash quantity becomes increasingly great. A large number of successful engineering example enlighten us that high performance high volume fly-ash concrete will have a wide application prospect with low water binder ratio. In order to extend the application of high performance high volume fly-ash concrete, we must carry out large-scale work of performance research on mechanical properties, hydration characters and the pore structure feature. As well, performances and mechanisms of high performance high volume fly-ash concrete with different water binder ratio and different fly ash proportion must be made clear.The performances of workability, compressive strength, chloride ion permeability, anti-carbonation, steel corrosion and the frost resistance are studied in this paper, with different water binder ratio and different fly ash proportion. The study can offer the base of theory and reference.The main works been done as following: 1.By orthogonal combination experiment, the effort of factors including water binder ratio, cementing material, fly ash content and sand ratio by orthogonal combination experiment were analyzed. Then the main influential factors were conformed. 2. Concrete mixture ratio design was carried out by changing a factor every time. The key techniques and the principles of high performance high volume fly-ash concrete would be found by analyzing the compressive strength and durability.The test result indicated: 1.The early strength can satisfy the engineering practices completely and the long-term strength is superior to common concrete. 2. High performance high volume fly-ash concrete have good performances of workability, compressive strength, chloride ion permeability, anti-carbonation, steel corrosion and the frost resistance, which comes from the process of HPC technique.