| As an industrial waste slag from the manufacture of iron or steel, the throughput of steel slag in china reach to about 100 million tons in 2014, while china’s steel scoria has accumulated storage of near 1000 million tons currently resulting in only 10% of the ratios of comprehensive utilization. The large quantities of steel slag not only take up much land, but also pollute environment seriously. With the technology of concrete compositing constantly, a technique that steel slag powder serving as the admixture replace the certain amount of cement has becoming mature in the study of concrete. Nonetheless, how to develop a maximum activity and maximum content of steel slag in concrete remains to be further researched.This task starts with the chemical excitation still slag and other composite cementitious materials and premising the mechanical properties and working performance of alkali slag concrete, this work comparatively studied the corresponding mechanical properties and durability of concrete in different mixed ratio of the gelling system with the excitation of activator. Meanwhile, the interface of concrete gelling system and aggregates-gelling system is analyzed by using XRD, SEM and other microscopic tools.The test shows that: alkali steel slag concrete can be formulated to meet the designed strength grade C30 with the condition of mixing 60% steel slag, 15% slag, 5% silica fume, 20% standard cement in the presence of 5% compound activator. Reducing the content to 40% steel slag and increasing the dosage to 35% slag can produce the concrete of the designed strength grade C40 and has better durability; The mechanical strength of the concrete formulated containing 5% fly ash instead of slag has no effect, while the working performance improved.The microscopic test indicates that the slag sample mixed 40% steel slag and 35% slag has particular properties of high hydration degree of the gelling system, compact structure, better cohesiveness of the aggregates-gelling system. |
PDF Full Text Request