Pull-out response of glass yarn from ettringite matrix: Effect of pre-impregnation and embedded length

Abstract The interest in textile-reinforced concrete materials has grown in recent years, owing to their many advantages (high strength, good corrosion resistance, non-toxicity, availability of raw materials, recyclability, etc.). However, the use of multifilament reinforcements for cements is challenging because the cement particles cannot fully penetrate the space between the inner filaments, thus leading to the decrease in the yarn–matrix bond and consequently the mechanical performance of the composite. To improve this bond, the glass yarns are typically pre-impregnated in a wet manner using mineral or organic powders. The objective of this work is to compare this conventional method with a recent method called pre-impregnation in a dry manner. It is based on using an alternating electrostatic field that allows powder to be impregnated into yarns. The pull-out response of alkali-resistant glass yarn embedded in the ettringite matrix is investigated and reported in this study. Three types of specimens were tested: a dry yarn, a yarn pre-impregnated in a wet manner with matrix particles, and a yarn pre-impregnated in a dry manner with different types of powder. Four embedded lengths are investigated and their effect on the result is discussed. We found that the pull-out behaviour is dependent on the pre-impregnation method, pre-impregnation powder type, and embedded length.