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Title: Evaluation of pore structures and cracking in cement paste exposed to elevated temperatures by X-ray computed tomography

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.
Authors:
 [1] ;  [2] ;  [1]
  1. Korea Institute of Construction Technology, 283 Goyangdae-ro, Ilsanseo-gu, Goyang 411-712 (Korea, Republic of)
  2. School of Civil and Environmental Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22220805
Resource Type:
Journal Article
Resource Relation:
Journal Name: Cement and Concrete Research; Journal Volume: 50; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 60 APPLIED LIFE SCIENCES; CEMENTS; COMPUTERIZED TOMOGRAPHY; CRACKING; DENSITY; EVALUATION; FRACTURES; MORTARS; PORE STRUCTURE; SCANNING ELECTRON MICROSCOPY; TEMPERATURE DEPENDENCE; X RADIATION; X-RAY DIFFRACTION