نوع مقاله : مقاله پژوهشی
1 استاد ممتاز دانشکده عمران دانشگاه سمنان
2 دانشجوی کارشناسی ارشد سازه، دانشگاه سمنان
3 دانشجوی کارشناسی ارشد سازه، موسسه رشد دانش
عنوان مقاله [English]
In this paper, the effects of concrete compressive strength, macro synthetic fibers named MEX-200 and its percentage, and also confinement of concrete cylinders on impact due to free fall of weights to specified mass is investigated in laboratory and the level of concrete destruction is studied. The number of specimens tested is 54 cylindrical specimens classified with 20, 30 and 40 MPa strength and 1, 1.5 and 2% fibers. Specimen weights are recorded before and after impact. In the impact test, the specimens were affected by two weights of 46.7 kg and 66.8 kg with 1.6 meters height. One layer of GFRP with a 90 degree angle was used to confine the specimens. Experimental results show that specimens with 20, 30 and 40 MPa strength without GFRP wrap, with 1 and 1.5% fibers, 33%, 25% and 20% respectively, and with 2% fibers, 66%, 50% and 40% increase the number of impact compared to specimens without fibers . For specimens with 20, 30 and 40 MPa with GFRP wrap, for without fibers, 500%, 400% and 340%, and for 1% fibers, 530%, 425% and 360%, and for 1.5% fiber, 566%, 450% and 360%, and for 2% fiber, 600%, 475% and 400% increase in the number of impacts is observed.