Effect of steel fiber on fracture characteristics and ductility of self-compacting concrete: experimental and theoretical investigation

Document Type : Article

Authors

1 Department of Civil Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran

2 Department of Civil Engineering, University of Mazandaran, Babolsar, Iran

Abstract

Adding steel fibers (SF) in SCC can change the cracking pattern and fracture performance. Hence, 75 notched SCC beams containing SF at volume percentages of 0.15, 0.3, 0.45, and 0.6% were made in this work and tested under the three-point bending load to investigate their brittleness and fracture behavior. To this end, work of fracture method WFM and size effect method SEM were used to analyze the fracture parameters. The results showed that increasing the steel fiber content from 0.15 to 0.6% increased fracture energy values obtained from WFM and SEM by 9.8 and 2.5 times, respectively, compared to SCC without fibers. Also, at a SF content of 0.6%, the characteristic length of concrete in WFM, and the fracture process zone and fracture toughness in SEM were 5.4, 3.3 and 1.7 times, respectively, those of SCC without fibers. The results of in WFM and in SEM showed that the fibrous SCC samples were more ductile. Eventually, obtained mechanical properties and test variables were used to develop multivariate prediction models for the fracture parameters of fibrous SCC. The prediction results of these models were compared the test data of the present study and other studies, and acceptable results were found.

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