Grafting of continuous polypropylene fibres by methacrylic acid monomers to improve their bonding to concrete matrix

Abstract

In this paper, methacrylic acid monomers grafted to continuous polypropylene fibres to make them hydrophile, while grafting experiments are designed based on Taguchi method in which temperature, monomer concentration, crosslinker concentration and time of reaction are selected as variable factors at four levels and several polypropylene fibres with various grafting degrees are obtained. Next, pull-out behaviour of modified fibres embedded to concrete is investigated and compared to raw fibres. In addition, influence of grafting on pull-out behaviour of fibres is addressed. Pull-out tests and scanning electron microscopy images verified the bonding improvement of the proposed fibres to concrete appropriately. Finally, optimum grafting degree to achieve the best bonding between the fibres and concrete with highest tolerated tensile load is determined.

Creep and residual properties of cracked macro-synthetic fibre reinforced concretes

“…Fibre reinforced concrete (FRC) is a high-performance material that is recommended in many applications in order to improve the service life of structures by means of its crack control capacity (Aslani and Nejadi, 2013;Ganesan et al, 2014). When incorporated into concrete, fibres will mainly start to carry stress after microcracking of the matrix begins (Mazhar et al, 2013). In the post-cracking stage, the fibres bridge the cracks and control their propagation by means of the chemical and physical bond or anchorage that develops during the fibre pull-out or slip processes (de Montaignac et al, 2013).…”