Study On Compound Admixture Of Circulating Fluidized Bed Ash And PVA Fiber

With the progress of society,the performance requirements of cement-based cementitious materials are getting higher and higher.Admixture compounding is one of the main ways of material evolution.By using the superposition effect of various component properties,Characteristics of the combination of effects,to overcome the performance of a single variety of defects,reduce costs.PVA fiber with its high elastic modulus and tensile strength and other excellent performance by the construction area of widespread concern,fiber composite cement-based cementitious material is its core.And PVA fiber dispersion is not good enough to bring the problem has been PVA fiber in the cement-based composite materials to get better use of obstacles.Circulating fluidized bed fly ash and slag(referred to as CFB ash)belongs to the circulating fluidized bed boiler combustion products,but most of the current in the bulk state,has not been used effectively and shows a gradually increasing emission trends in China,there is an urgent need to for its effective use.So the purpose of this article is to use appropriate characterization methods developed a suitable technique to PVA fiber evenly dispersed in CFB ash as compound admixture,its purpose: one is to solve the poor PVA dispersion and clear PVA fiber dispersion,2 it is to let the PVA fiber CFB ashes scattered in advance as a composite admixture,make its get better on engineering use value.Through the study of PVA fiber in toughening type circulating fluidized bed ash composite admixture system of dispersion characterization method;The dispersion of PVA fiber in composite gelled material and improvement measures;Dispersion on the workability of the complex system and the influence of mechanical properties and microstructure of the composite system analysis;Toughening composite admixture type circulating fluidized bed ash research on the influence of cement base material;Get the following conclusion:1.When the mixing technology with per dispersion method,fiber volume fraction at 0.10%,fiber with 6mm in diameter 19?m PVA3 can enable fiber's dispersion in the controllable range to achieve the best.2.Fiber content and dispersion resistance have influence on the flexural strength,and the uniform dispersion of fibers in the cement matrix composites is a necessary condition for the full play of its toughening and crack resistance.3.To a certain extent,the increase of fiber length and fiber diameter can improve the bending strength,but the effect is not obvious.4.Cement matrix and fiber in the hardening of the cement matrix can form a good bond.5.The addition of toughening circulating fluidized bed ash can improve the impact resistance of concrete and compensate for the early shrinkage of cementitious cementitious materials.