Title: Pore Structure of Calcium Sulfoaluminate Paste and Durability of Concrete in Freeze–Thaw Environment
Author(s): Kyle de Bruyn, Eric Bescher, Chris Ramseyer, Seongwon Hong, Thomas H.-K. Kang
Appears on pages(s): 59-68
Keywords: calcium sulfoaluminate cement, freeze–thaw environment, mercury intrusion porosimetry, nitrogen sorption porosimetry, portland cement
Mercury intrusion and nitrogen sorption porosimetry were employed to investigate the pore structure of calcium sulfoaluminate (CSA) and portland cement pastes with cement-to-water ratio (w/c) of 0.40, 0.50, and 0.60. A unimodal distribution of pore size was drawn for CSA cement pastes, whereas a bimodal distribution was established for the portland cement pastes through analysis of mercury intrusion porosimetry. For the experimental results generated by nitrogen sorption porosimetry, the CSA cement pastes have a smaller and coarser pore volume than cement paste samples under the same w/c condition. The relative dynamic modulus and percentage weight loss were used for investigation of the concrete durability in freeze–thaw condition. When coarse aggregate with good freeze–thaw durability was mixed, air entrained portland cement concrete has the same durability in terms of relative dynamic modulus as CSA cement concrete in a freeze–thaw environment. The CSA cement concrete with poor performance of durability in a freeze–thaw environment demonstrates the improved durability by 300 % over portland cement concrete. The CSA concrete with good performance aggregate also exhibits less surface scaling in a freeze–thaw environment, losing 11 % less mass after 297 cycles.