Elastic modulus of self-compacting fibre reinforced concrete: Experimental approach and multi-scale simulation

Evaluation of the elastic properties of self-compacting fibre-reinforced concrete is one of the primary concerns in civil and structural engineering. This paper investigates the elastic properties of self-compacting fibre-reinforced concrete with varying coarse aggregate and steel fibre content. Traditionally, the elastic properties of concrete are measured experimentally which incurs significant cost and time overhead. In this paper, a two-step homogenisation approach is proposed for predicting the elastic properties of self-compacting fibre-reinforced concrete. In the first step, the mortar, air voids and aggregates are homogenised based on mean-field homogenisation using the Mori-Tanaka model. X-ray computed tomography (CT) scanning technique was employed to analyse and determine the volume fractions, shapes, numbers of pores for validation purposes. In the second step, a finite element model of representative volume elements is generated with steel fibre inclusions and homogenised concrete to determine the overall macroscale elastic modulus of SCFRC. The results show that the content of aggregates, steel fibres and porosity in the mix has a substantial effect on the elastic modulus. The influence of fibre orientation on the elastic modulus SCFRC is also investigated. The results obtained from the homogenisation method were compared with those obtained from an experimental study and it was found that the maximum error in the elastic modulus prediction using the proposed multiscale homogenisation approach was less than 4%. This agreement between multiscale homogenisation results and experimental data highlights the feasibility of using the two-step homogenisation approach in the development of SCFRC. It has been demonstrated that the proposed homogenisation method can efficiently replace timeconsuming laboratory tests, saving both resources and time.

Automated summary

Evaluation of the elastic properties of self-compacting fibre-reinforced concrete is important in civil and structural engineering. This paper proposes a two-step homogenisation approach to predict the elastic properties of self-compacting fibre-reinforced concrete. The results show that the content of aggregates, steel fibres, and porosity significantly affect the elastic modulus, and the proposed homogenisation method can efficiently replace time-consuming laboratory tests, saving both resources and time.