Behaviour of high-strength concrete with dolomitic aggregate at high temperatures

Tests were carried out on concrete with normal Portland cement, silica fume and dolomitic aggregate subjected to temperatures of 20–800°C to determine the effect of temperature on the phase composition and pore structure development, and physico-mechanical properties of concrete specimens. It is shown that the reduction in hydrate phase volume is connected with the pore structure coarsening manifested by the evident growth in pore median radius and total porosity values. Damage to the structural integrity of concrete is markedly influenced by the level of temperature elevation. This process is described by a three-stage model which incorporates deductions made from this study and those cited from the literature of similarly affected concretes.