Characteristics and prediction of creep of a saturated mortar under variable temperature

Abstract

Synopsis In a previous paper it was shown that four strain components can be identified when concrete, stored in an environment with a varying temperature, is subjected to a sustained load. They are: (a) elastic strain; (b) delayed elastic strain; (c) transitional thermal creep; (d) flow. Each component is, in some sense, related to temperature, and the first part of this paper is devoted to the development of explicit functions for each of the components in terms of temperature and time. In particular, it is shown that all the time-dependent strains can be generated from a single curve in which flow is plotted against weighted maturity. The expressions are used in the second part of the paper to predict the strains in mortar tubes under torsional loading, when subjected to severe regimes of temperature change. The predictions show reasonable agreement with experimental results, and a simplified method of prediction, for use in practice, is also demonstrated.