A review on ultra high-performance fibre-reinforced concrete with nanomaterials and its applications

Abstract

Ultra high-performance concrete (UHPC) is an advanced concrete which exhibits a higher performance mostly in all aspects and has a compressive strength higher than 150 MPa. The paper reviews the usage of different types of fibres, nanomaterials, mineral admixtures, preparation techniques and the utilization of UHPC. Improved microstructure, reduced porosity and homogeneous mixing are the basic requirements of the UHPC design. Though UHPC helps in the preparation of structural members at lesser size, it requires an enormous amount of cement which is accountable for a huge CO2 emission, abrasion and cracks; hence, supplementary cementitious materials might be utilized as a limited alternative for cement without sacrificing the strength of concrete at lesser cost. The nanomaterials act as a nucleation site for the C-S–H gel formation by filling the voids and pores, thereby aiding to attain a denser microstructure for UHPC and also delaying the nucleation of the cracks at the nanoscale. The fibres used in the UHPC help in energy dissipation and also produce a bridging effect for micro- and macro-cracks. Based on the investigations, it has been found that the usage of medium hooked-end steel fibres and a hybrid combination of fibres with nanomaterials helps in improving several properties of the UHPC.