Comparison Crack Resistance of RC Beams with and without Transverse Reinforcement after Shear Testing

Abstract

Main parameters, which characterize shear strength, are crack distribution, width of diagonal crack opening and angle of inclined crack. There are in this article, comparison crack resistant of testing reinforced concrete (RC) beams on the shear with such variable parameters like presence or absence internal reinforcement, different shear span, and presence or absence external composite reinforcement. Shear span (relative span to effective depth ratio) was acquired the following values: a/d=2, 1.5, 1. For internal reinforcement, rebar’s A240C with diameter 8 mm and steps 100 mm was chosen. The composite FRCM system was like external reinforcement with three stripe of composite fabric with width 70 mm and step 100 mm. Eight RC beams were tested. After testing, we discovered that the most influenced on the serviceability capacity was shear span. Internal transverse reinforcing increased shear strength on the same level and it was independent from shear span and other factors. Only quantity of reinforcing determine level of increasing shear capacity. FRCM system is efficient strengthening system, which significant increase shear crack resistant for RC beams. External FRCM reinforcing increase shear crack resistance on the same percentage and independent from presence or absence internal reinforcement.

Peculiar aspects of cracking in prestressed reinforced concrete T-beams

“…The main difference is that the loading level at which inclined cracks appear is 53 % higher than the loading level at which the first normal cracks appear in the investigated reinforced concrete elements. In this case, as expected, the prestressing level of the main longitudinal reinforcement has a great influence on the loading, which corresponds to the appearance of the first normal cracks in comparison with the loading when the first incline cracks appear, which corresponds to the test data [26][27][28][29]. The appearance of inclined cracks was fast, i. e., there was a non-proportional increase of deflections of the investigated elements.…”