When cement-based materials are exposed to the high temperatures induced by fire, which can rapidly cause temperatures of over 1000 C, the changes in pore structure and density prevail. In the present study, mortar specimens were subjected to a series of increasing temperatures to explore the temperature-dependent evolution of internal pore structure. High-performance X-ray computed tomography (CT) was used to observe the evolution of temperature-induced discontinuities at the sub-millimeter level. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to investigate the cause of physical changes in the heated mortar specimens. Results exhibit the changes in pore structure caused by elevated temperatures, and thermally induced fractures. We discuss the progressive formation of thermally induced fracture networks, which is a prerequisite for spalling failure of cement-based materials by fire, based on visual observations of the 3D internal structures revealed by X-ray CT.
Bibliographical noteFunding Information:
This work was supported by grants from the New & Renewable Energy program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) funded by the Korean Ministry of Knowledge Economy (No. 2012T100201733 ), and by the Korea CCS R&D Center (KCRC) grant funded by the Korea government (Ministry of Education, Science and Technology , No. 20120008929 ).
All Science Journal Classification (ASJC) codes
- Building and Construction
- Materials Science(all)