The Study On Early Mechanics And Frost Resistance Of Lightweight Aggregate Concrete

2In this paper, pumice lightweight aggregate concrete (LWAC) of LC20,LC25 and LC30, which are specially suitable for being used in cold region, are compounded with the method of mixing fibers, high-quality air-entraining agent and mineral admixtures. In view of the environmental features of cold region,Lightweight aggregate concrete early strength development later than normal, with a view to increasing age, the capacity of a smooth enhancing brittle, in the age of 28 days compressive damage, the pumice aggregate were completely shear failure; lightweight aggregate concrete with early modulus of elasticity growth are small compared with ordinary concrete, the plastic properties of performance; lightweight aggregate concrete stress-strain curves of concrete forms and general similar, but larger deformation range; the use of sub-equation of stress-strain curves of concrete in 28 of LC30 days of fitting in better fitting results.Resources for the northern region and the surface characteristics of pumice ,studing the different ash content of flour durability, cold regions taking into account the environmental characteristics of hydraulic structures, the durability design of the carbonation performance, impermeability, chlorine properties of ion erosion of the test; come incorporation of fly ash lightweight aggregate concrete impermeability properties for the best between 25% -32%; fly ash lightweight aggregate concrete carbonation on the degree of influence and a positive correlation between fly ash; 30% less than the fly ash lightweight aggregate concrete guarantee that the late development of higher strength.In this paper, a lightweight aggregate concrete, fiber reinforced concrete and lightweight aggregate concrete rubble of the cube compressive strength, axial compressive strength, flexural strength and modulus of elasticity, compression damage test, comparison of polypropylene fiber and gravel lightweight aggregate concrete for enhanced or toughening effect; as well as fiber-reinforced lightweight aggregate concrete and lightweight aggregate concrete rubble of the destruction of the form of contrast, fiber damage is mainly expressed in the form of transverse shear, damage to lightweight aggregate concrete rubble occur when loose aggregate.In this paper, based on LC30 lightweight aggregate concrete, in the introduction of fiber can significantly improve the lightweight aggregate concrete properties of the antifreeze. Gravel to replace the part after the lightweight aggregate, lightweight aggregate concrete strength despite some improvement in performance has declined more antifreeze. Fiber lightweight aggregate concrete after freeze-thaw damage in the study to investigate the degree of injury for the study, drawn from the performance of lightweight aggregate concrete durability in the fiber content for 0.9kg/m3, the antifreeze properties. The use of polynomial fitting broken fiber lightweight aggregate concrete and the number of freeze-thaw damage the relationship between the degree of change, a better fitting relations. In a simulated environment under the condition of outdoor fiber lightweight aggregate concrete freeze-thaw cycle three temperature test found that increase in the number of freeze-thaw, temperature conduction more smooth, enhancing the capacity of co-deformation, compared with the standard freeze-thaw cycles and the mass loss of strength in the same the smaller the number of freeze-thaw, when the fiber content for 0.9kg/m3 less frost heave stress, deformation capacity to coordinate the best, 75 times the volume of development of frost heave for about 2mm.