On-line version ISSN 1980-5373
TOLENTINO, Evandro et al. Structural Evaluation and Performance of Portland Cement Concretes After Exposure to High Temperatures. Mat. Res. [online]. 2002, vol.5, n.1, pp. 27-36. ISSN 1980-5373. http://dx.doi.org/10.1590/S1516-14392002000100005.
We evaluated the "residual" thermal conductivity of Portland cement concretes (with characteristic compressive strength at 28 days, fck, of 20 MPa and 50 MPa) at room temperature after heat-treating at 180 °C, 300 °C and 600 °C. The description of the geometry of the structure was carried out using mercury intrusion porosimetry and nitrogen sorption. The results showed a decreasing tendency of residual thermal conductivity, which we attributed to heat-induced concrete degradation. Furthermore, the results from mercury intrusion porosimetry and nitrogen sorption tests showed that a coarser pore structure is produced with the raise of heat-treatment temperatures.
Keywords : concrete; mercury intrusion porosimetry; nitrogen sorption; residual thermal conductivity.