Shear strength of steel fibre self-compacting concrete in precast concrete corbels
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Date
2017
Authors
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Journal ISSN
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Publisher
Universiti Teknologi Malaysia
Abstract
Self-compacting concrete (SCC) has been well known as an innovative concrete which requires zero mechanical vibration and being compacted solely under its own weight. Hardened SCC behaves similarly to the vibrated conventional normal concrete (NC). Normal concrete acts very brittle, thus, steel fibre self-compacting concrete (SFSCC) was formed by incorporating steel fibres into SCC. The objective of this study was to examine the effectiveness of SFSCC in the structural behaviour of precast concrete corbel to solve the reinforcement congestion problem caused by multiaxial forces in disturbed region by partially replacing the existing design reinforcement with steel fibre. Possible reduction of reinforcement in corbels was investigated using the optimised mix design of SFSCC, which developed in the early part of this study. 1.0% fibre volume fraction was selected as optimised mix of SFSCC for precast concrete corbel. A total of ten precast concrete corbels with three different concrete mixtures were cast and tested under vertical loading having different shear span-to-depth ratios and reinforcement configuration. Based on the experimental results, SFSCC showed improvements on the shear resistance, failure mechanisms and ductility behaviour of precast concrete corbels. The results also showed that up to 50% main reinforcement or shear reinforcement can be effectively replaced with the inclusion of 1.0% by volume of steel fibres. It has been noticed that the suggested semi-empirical equations which was developed based on strut-and-tie model (STM method) and shear-friction method produced good agreement due to its ability in giving the closest prediction and correlation with the experimental results. The calculation using STM method and shear-friction method registered (VExp/VCalc) ratio of about 0.96 and 1.03, respectively, with the corresponding standard deviation of about 0.07 and 0.03. Thus, it was concluded that the proposed semi-empirical equations were strongly recommended to be used in predicting the shear strength of precast concrete corbels made of SFSCC
Description
Thesis (Ph.D (Civil Engineering))
Keywords
Precast concrete—Testing, Strength of materials—Testing, Self-consolidating concrete