Experimental and analytical study on behavior of pull-out failure of reinforcing bar embedded in concrete blocks

摘要

The bond between concrete and steel reinforcing bars is a very important functional requirement of reinforced concrete as a composite building material. This paper focuses on the comparison between the outcomes of the investigation dealing with bond strength at different levels of depth of concrete. The levels of concrete can be found in reinforced concrete columns, walls, and slabs. This paper presents an experimental and analytical analysis of the pull-out test on 32 concrete specimens. In the experimental part, eight concrete specimens grouped into normal self-compaction concrete (SCC) and lightweight SCC, as well as mixtures between them, were tested. In each sample, four steel bars were embedded in concrete at different locations: at the top, two samples in the middle, and at the bottom of the sample. Moreover, the slip and bond strength of each steel bar was measured using the pull-out test. It was found that, in all the studied mixes, the average bond strength is greater in normal SCC than in lightweight SCC. This study recorded about 27.86% difference for mix CM compared with mix MCF100. An analytical analysis of nonlinear finite element (FE) was conducted for 12 reinforced concrete specimens; three different mixes are considered. A nonlinear FE analysis has been carried out to analyze the specimens that were tested experimentally. The results obtained from the experimental analyses and FE are compared with each other. The results revealed that the FE failure behavior indicates a good agreement with the test behavior.