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论文类型：会议论文

发表时间：2010-01-01

收录刊物：CPCI-S

页面范围：139-142

关键字：long-term; expansion; steel fiber

摘要：As we known, expansive concrete may improve cracking properties of concrete structures as a result of compensating shrinkage. By distributing steel fibers into expansive concrete to form a type of composite which is called steel fiber reinforced expansive concrete, the tensile strength of concrete can be further increased as well as the post-crack behaviors of concrete. For this concrete, a key point to ensure high performance and safety of concrete structure is to keep a stable expansive deformation during long-term service. Therefore, this paper presents a series of tests to investigate the long-term performance of deformation of steel fiber reinforced expansive concrete. The test included some 3-year specimens which were focused on a study of the development of the restrained expansive deformations with ages of steel fiber reinforced expansive concrete when bearing different restrictions such as steel bars and steel fibers. For all specimens, experimental parameters or variables are mainly involved in 2 ratios of steel bar reinforcement, 4 volume fractions of steel fiber and 4 dosages of expansion admixture. The test results showed that the expansive deformation developed with ages but after 90 days the increasing amplitude was no longer significant. In addition, the expansion of concrete decreased with increasing of both steel bar reinforcing ratio and steel fiber volume fraction. Besides, when being in a lower dosage of expansion admixture, the specimens presented remarkable retraction of the expansive deformation. However, when exceeding a certain dosage of expansion admixture, the long-term expansive deformation had less change with ages and almost remained the same as 90-day deformation, namely less losses of deformation. Hence, for steel fiber reinforced expansive concrete, using an appropriate dosage of expansion admixture could meet the requirements of designed strengthening and could also compensate shrinkage of concrete.