Determining Shear Capacity of Ultra-high Performance Concrete Beams by Experiments and Comparison with Codes

Abstract

In this research, nineteen specimens of ultra-high performance fiber-reinforced concrete rectangular beams are made and their shear resistance is determined experimentally. The results are compared with estimations by ACI 318, RILEM TC 162-TDF, Australian guideline and Iranian national building regulations. To compare the code estimations, the ratio of experimental shear strength to predicted shear strength is calculated for each code. This ratio is actually a measure of safety factor on one hand and a measure of precision of the estimation on the other hand. Based on the results of both studies, the authors conclude that the Australian guideline with a ratio of 2.5 provides the minimum experimental to predicted ratio while the Iranian National Building Regulations with a ratio of about 10 provides the highest experimental to predicted ratio. This ratio obtained for ACI and RILEM was about 8 and 3.6 respectively. The Iranian and ACI codes provide basically the same strength estimation but both are very conservative, which may be interpreted as mainly because the codes are dubious about the precision of their own estimations. However, RILEM and Australian codes, estimate the shear resistance with reasonable margin of safety.