Study On Properties Of High Fly-ash Content Concrete

As the industrial byproduct, the emission of fly ash is very enormous, high fly-ash content concrete(HFCC) can utilize the potential activation of fly ash fully, which is industrial waste residue, reduce cement consumption and the production cost of concrete, turn waste into wealth , melt and hurt it as the profit. It can also economize a large amount of valuable land which piles up the fly ash, which greatly exert its play to high-performance advantage, improving the work, durability and physics mechanics performance of concrete, high fly-ash content concrete can economize the cement, and consume a large amount of fly ash, which is effective very much for lighten environmental load. The high fly-ash concrete, as a kind of new materials, has its unique superiority, however, the range of application is not big at present. Mainly because the performance of HFCC can not meet project's needs in some aspects very well, such as its early intensity being low. It is bad to resist carbonization performance and protect reinforcing bar. In addition, the technical staffs idea has limited its development. As the technology perfects constantly, the performance of HFCC improve constantly, It will have wide application prospect in future surely. This text represents the study on the main performance of HFCC, combining practice data, and makes every effort to find and improve the performance of HFCC, raising their use potentiality actually. Several respects under main research in the article:1. Physical and chemical property of the fly ashFly ash is one of the main compositions of HFCC. The natures of the fly ash influence the performance of the finished product concrete directly. Several main physical and chemical properties which have most close relations with HFCC are introduced: the density, detailed degree, particle form, chemical element composition etc.2. Concept and development of the HFCCHigh fly-ash content concrete means the concrete in which the dosage of fly ash is greater than 30% and the concrete is in flow state. Its research originated from Britain first, the main function of fly ash in high fly-ash content concrete can be summarized for the active effect, collect the material closely knit packing and particle form effect, the physical and chemical mutual effect of cement, fly ash, and the different powder material.3. the early and harden performance of HFCCThe performance of getting apt, slump, carbonization-resistance, and the development of intensity are discussed in this article. And the calculation method of temperature stress of HFCC and control method are discussed emphatically.4. Quality control of the HFCCThe quality control of the HFCC is essential, which includes the choice of the raw materials, design to the maintenance of the concrete in match ratio, " Paul rice intensity expand formula "is recommended to design HFCC and wet method of maintaining etc. of concrete is introduced in the article.5. the project application of HFCCThe late intensity of HFCC has no difference with the ordinary concrete, and the heat of hydration of HFCC is lower than the ordinary concrete. So the high fly-ash content concrete is used in the road and structure project gradually.Through this text research, the theory on development and application of high fly-ash content concrete will be established.