Project application of the high-performance concrete of fly ash The summary Every performance of this text to high-performance concrete of fly ash has done detailed research, and to the concrete respectively to person who mix of fly ash Kinds of influence of performance and fly ash concrete some questions that should notice carry on analysis and discussion in not constructing. 1. Summary Fly ash, as a kind of industrial waste material, resources are abundant , cheap, and contain a large amount of active composition , it is modern concrete Central Africa A often important component part . The high-quality fly ash is applied to the concrete rationally , not only can replace the cement partly , save the fabrication cost of the project, And, its peculiar performance can be used in the concrete of various kinds of instructions for use very effectively, improve the performance of the concrete, It is the ideal in the high-performance concrete that admixes the material . Among it is at concrete not modern, whose name is already with cement in fly ash, collect material , water , admixture and Kind is important, become a component part in concrete. Fly ash high-performance concrete regard durability as main goal go on design mix Congeal the soil . It regards excellent durability (instead of the high strength) as the main characteristic , that is to say, concrete capital of any grade of intensity Can make into the high durability concrete . In order to reach high durability, the performance that the fly ash concrete should possess is: Mixing the state newly well Work,namely, without emanating, secreting by water, so that shaping the even , closely knit by mobility, harden not shrinking subsiding early water and Water shrink light, warm to rise low, harden course is it dwindle to do, in order to reach having the initial crack, the permeability after hardenning is low. 2 function and effect of the fly ash are fly ash material technology and application foundation of the project. Mix and add the powder of the concrete Coal ash, in conformity with understanding that the function of the fly ash is made overallly, by volcanic ash react and economic component part general to fly ash originally Read , expand technological consciousness of fly ash effect to , make fly ash function can serve performance of concrete improve with quality raising better. The role in concrete of fly ash has the following several points: (1) . Shape effect: It is spongy vitreous body , little pearl of silicate glass of aluminium that the main mineral of the fly ash makes up , smooth the body surface of these spherical glass, the grain size is thin, the quality is pre-pressing, inside smaller than the surface area, the strength of absorbing to water is small, this line of physical characteristics, reduce concrete rub obstruction inside , favorable to improvement , concrete of mobility not merely; And, have reducing water function in various degree on the concrete; (2) . Active effect: The active composition SiO2 of the fly ash and water result of AI2O3 and cement react in a situation that there is water, producing water silicic acid calcium (C-S-H ) and water sour calcium (C-A-S-H ) of sulphur aluminium, these responses nearly all go on in the grout hole, water that produce result pack , cut apart the heavy original hole , make the hole thinning, can reduce the hole rate within the concrete , change the hole structure , improve glueing the function of forming of concrete every component part ; (3) . Collect the material effect a little: Very small particle of fly ash even to is it among cement particle , pack the hole to distribute, play a role in getting to thinning hole , meanwhile , prevent glueing gathering each other of the cement particle, and make it in state of dispersing , help water of the mixture to react, the fly ash will not be totally with reacting with water result of the cement, can keep its collecting the material effect a little for a long time ; (4) . Effect of the interface: It is the weak link in the concrete structure to collect the interface between the material and cement stone, width of transition area as water for dust than, collect there arent material , transition area have than grout body more, heavy hole. Mixing can reduce the regional width of the transition to add the fly ash , interfere Ca (OH ) orientation of 2 crystal in the transition area, improve the intensity of interface and density in the concrete. (5) Performance of the fly ash concrete The change of the fly ash to concrete performance can be divided into three stages: 1 . Mix concrete stage newly: Influence the coagulation time of the concrete , is improving and easy , change rheology nature , can improve pump ,etc.;(6) . The concrete stage while hardenning: Regulate the course of hardenning, reduce the heat of hydration; 3 . The concrete stage after hardenning: Rais