Laboratory investigation of reinforced concrete beams with several samples of FRP fibers under bending test

Using fibers to repair and strengthen concrete elements is a very effective method that has been used in recent years. By using FRP fibers, the bending and shear capacity of beams and columns and other concrete components can be significantly increased. In this article, the changes in flexural strength and strain of ۳۶ standard rectangular cube concrete beam samples, including six control samples and thirty beam samples reinforced with five different types of FRP fibers under seven-day and twenty-eight-day bending loading, are investigated in the laboratory. Due to the low weight of fibers, strengthening with them does not have an effect on increasing the weight of the structure, which is important compared to other methods of strengthening concrete structures. Also, due to the low thickness of the fibers, there is no change in the architecture of the structure, these factors can be one of the most important advantages of these fibers. In general, the use of FRP fibers, especially carbon fiber ۲۰۰, is recommended as a suitable material for strengthening and improving structures. According to the tests and the increase in load capacity of the reinforced samples compared to the control sample, it was found that the operation of strengthening concrete beams is very satisfactory. One of the important points of the three types of carbon fibers compared to the control samples was that the carbon samples under a force of ۱۰۰ newtons and even in some samples under a force of ۲۰۰ newtons had zero deflection, which is a very good characteristic for the design of reinforced concrete structures. It is made with FRP carbon fibers.

کلیدواژه ها:

Retrofitting ، FRP fibers ، bending test ، bending strength