نوع مقاله : مقاله پژوهشی
نویسندگان
1 کارشناسی ارشد مهندسی سازه، گروه مهندسی عمران، دانشگاه آزاد اسلامی قزوین، ایران.
2 گروه مهندسی عمران،واحد قزوین،دانشگاه ازاد اسلامی قزوین،ایران.
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Few researches are available on the behavior of fiber-reinforced concrete and especially high strength fiber-reinforced concrete under cyclic loading. The purpose of the present study is to investigate the effect of using fibers on the rheological and mechanical properties of high strength concrete, and also the effect of using fibers and different loading speed on the high strength concrete beam under different cyclic loadings. To this end, two types of fibers including hooked end steel fiber and polypropylene fiber were used. In this research, seven mix design, each includes two designs, were used; one design was used as an observant and six fiber designs; The slump test was performed on the fresh concrete in order to investigate the rheological properties of the mix designs. Also, the mechanical properties of high strength concrete were determined using compressive strength test, splitting tensile strength, module of elasticity, flexural strength test under uniform loading, and high strength fiber-reinforced concrete beam test under cyclic loading. Scanning Electron microscopy (SEM) was also performed on concrete specimens at 28 days of age. Generally, the strength values for the samples with steel fiber content is higher than the strength values recorded for other samples. The best monotonic and cyclic flexural strength results belong to the samples with 0.25% polypropylene and 0.5% steel fibers. The cyclic flexural strength results show that polypropylene fibers play a relatively good role in cumulative energy at low displacement levels and micro-cracks.
کلیدواژهها [English]
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