Bond of a strand in a cementitious matrix

Abstract

Although the bond of a strand in a cementitious matrix is certainly predominated by the bond properties between filaments and matrix, more detailed information is needed to evaluate the failure mechanisms of such a complex system under a pull-out load and hence to allow an analytical and numerical simulation of this composite. Thus, in this study different innovative test methods are developed and used to identify the debonding process of a strand as a result of the pull-out process and ascertain the contact faces between the individual filaments and the matrix. Additionally, numerical procedures are proposed which use the findings to allow, for the first time, a direct relationship between the load history of a pull-out test, to the failure process of an AR-glass strand, by means of a mathematical function; the so-called active filament versus displacement relation NF(Ω). Together with the load versus displacement relationship P(Ω) also derived during the pull-out test, an analytical characterisation and simulation of the bond between an AR-glass strand and a cement based matrix will be possible.