Evaluation of the effect of the strength of steel fibres in the residual strength of concrete

• Grant number: 15/27010-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2016
• End date: February 28, 2017
• Field of knowledge: Engineering - Civil Engineering - Construction Industry
• Principal Investigator: Antonio Domingues de Figueiredo
• Grantee: Julie Silva Assunção
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The high strength concrete is a growing trend in current technical means, associated with the use of steel fibres for their reinforcement. There is an economic advantage when low fibre content is applied because the impact on the workability is lower. However, the low content of fibres may induce a reduction on the post-cracking strength due to the fibres rupture. Thus, the use of steel fibres with a higher level of tensile strength could minimize the occurrence of fibres rupture and preserve the residual strength of the composite. Then this project aims to evaluate the use of new steel fibres with higher tensile strength in order to maintain the same level of post crack strength when high strength concrete is used as a matrix. An experimental study is proposed in order to evaluate the effect of high strength steel fibres in the post-cracking behavior of the composite. The evaluation of the composite will be made through the flexural standard test with closed loop system as regulated in Europe (EN14651:2007). This kind of test will provide a higher precision to evaluate the post-crack strength at the service limit state which have a special interest for structural applications. Thus, it is possible to assess if there is a gain in structural behavior with increasing fibre strength.