نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار، دانشکده مهندسی معدن و متالورژی، دانشگاه یزد
2 هیئت علمی
3 کارشناس ارشد، دانشگاه یزد
4 دانشجوی دکتری، دانشگاه کاشان
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Concrete is one of the most important materials in today's society, which is widely used in many construction projects, foundations buildings,, dams, and tunnel stability. The tensile strength of concrete is one of the most basic and key features that has a significant impact on the stability of structures, tunnels, and bridges. Tensile strength of concrete is measured using direct tensile tests on rectangular concrete samples with dimensions: 19 cm in length, 16 cm in width, 6 cm in thickness and a central hole of 9 cm in diameter. The concrete specimens prepared in laboratory by mixing cement, fine sand, gravel, and water in appropriate proportions. Calibration of the new direct tensile strength test apparatus was carried out to determine the tensile strength of different brittle materials (gypsum and concrete) under various loading rates, and different mixing design types. The direct tensile strength tests were accomplished by a compressive-to-tensile load converter (CTLC) fitted with the specimens and placed in the universal testing machine in the laboratory. The loading rates of 5, 10, and 15 kg/s were considered for the indirect Brazilian tensile strength tests and the loading rates of 2, 2.5, and 3 mm/min for the direct tensile strength tests. The results of this paper show that the direct tensile strengths measured by the CTLC apparatus are approximately 25% lower than those measured by the Brazilian tests. The average tensile strengths of the geo-material samples increase as both the loading rate and the ratio of fine sand to gravel increase.
کلیدواژهها [English]
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