Property Study On Sintered Fly-ash Concrete

In the 21st century, the concrete structure is also the prevailing structure in the civil engineering. Along with the requests of modern projects increasing, high stratification, great span, big formalization, the performance deficiency of the common concrete is increasingly important, the defects limit the concrete structure development. At present, the experts and scholars at home and abroad put the research focus on improving concrete strength grade, meanwhile, protecting the natural environment, saving energy and reducing consumption.Fly-ash is the main material of the fly-ash ceramsite, adding proper amount of binder, processing to sphere, sintering and expanding to a kind of artificial industry wasting lightweight aggregate. Sintered fly-ash concrete is a kind of lightweight aggregate concrete, it has many property advantages, such as lightweight, insulation, heat insulation, refractory , seismic and so on.The study takes the main research object on sintered fly-ash concrete, preparing the lightweight concrete with the strength grade from 15 to 55, using shale haydite and fly-ash ceramsite respectively. Study on mechanical property experiments: cubic compressive strength, splitting lension strength; The durability test: anti-carbonization test and fatigue test, combining with the common concrete of the same strength grade to comparatively analysis the property feature of sintered fly-ash concrete. The microstructure of sintered fly-ash concrete and common concrete are studied by electron microcopy observation and energy spectrum analysis, comparatively analyzing the bond features of the interface between aggregate and cement slurry, the distribution feature of hydration products in the interface zone.According to the test data and theoretical analysis, we find that the lightweight concrete strength is in the main relation to the concrete water-binder ratio and the lightweight aggregate strength. Under the condition of a certain lightweight aggregate strength, the lightweight aggregate concrete strength is increasing with the water-binder ratio reducing; Under a certain water-binder ratio, the lightweight aggregate strength plays a key role in the lightweight aggregate concrete. Sintered fly-ash concrete has not a obvious interfacial transition zone, having a favorable durability.