Papers by Author: Oliver Weichold

Abstract: Glass rovings undergo a loss in tensile strength when aged in highly alkaline concrete. Based on the hypothesis that this loss is due to hydrolysis of the silicate network, binary polymer/pozzolan and ternary polymer/pozzolan/cement coating formulations have been developed in order to provide both corrosion protection and improved fibre-matrix adhesion. While the ternary mixtures were found to do either or, the best overall result was obtained with the binary mixture poly(vinyl acetate)/silica 20:80, showing a 1.8-fold increase in the pull-out load and a 1.6-fold increase in the residual tensile strength when compared to the as-received glass.

Abstract: Cement-in-polymer (c/p) dispersions allow the full utilisation of the reinforcing abilities of multifilament rovings in concrete. In this work the role of the polymer properties on the performance of the c/p dispersions is investigated and discussed. Two model polymers are chosen and c/p dispersions made with these are investigated regarding the water ingress velocity (NMR), the phase development during cement hydration (XRD), and the microstructure after cement hydration (SEM). Best mechanical performance is achieved with the hydrophobic poly(vinyl acetate) which regulates the water ingress and causes a slow hydration of the cement.