ABSTRACT
The understanding of concrete structures functioning is largely simplified by the numerical modelling of their mechanical behaviour. Interesting advances have been made these last years in this domain by accounting for non-linear behaviours of materials in models. However, many other progresses must be made for predicting with a sufficient accuracy long term behaviours and the durability of such structures. Nowadays, highquality experiments can be performed. They are the indispensable condition for the completion of these progresses. One of the important questions, which has actually no fully satisfactory answer, in the understanding of creep mechanisms is the impact of cracking on the irreversible part of the creep strain. Some attempts were made a few years ago to illustrate and explain their interactions (Smadi, Slate, and Nilson 1985; Smadi, Slate, and Nilson 1987; Smadi and Slate 1989; Rossi and Acker 1988; Rossi, Godart, Robert, Gervais, and Bruhat 1994). In this context, a new study on the impact of cracking on long term behaviours is now under way at the french Laboratoire des Ponts et Chaussees, Paris. The first stage of this study is presented here. It consists in an adaptation to high level loads of the classical compression creep test device, developed at the LCPC many years ago (LCPC 1976) and used by different researchers (Abiar 1986; Laplante 1993; Leroy 1995).
