Restrained shrinkage cracking of cementitious composites containing soft PCM inclusions: A paste (matrix) controlled response
- Univ. of California, Los Angeles, CA (United States)
- Univ. of Rhode Island, Kingston, RI (United States)
- Arizona State Univ., Tempe, AZ (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
The addition of phase change materials (PCMs) has been proposed as a way to mitigate thermal cracking in cementitious materials. However, the addition of PCMs, i.e., soft inclusions, degrades the compressive strength of cementitious composites. From a strength-of-materials viewpoint, such reductions in strength are suspected to increase the tendency of cementitious materials containing PCMs to crack under load (e.g., volume instability-induced stresses resulting from thermal and/or hygral deformations). Based on detailed assessments of free and restrained shrinkage, elastic modulus, and tensile strength, this study shows that the addition of PCMs does not alter the cracking sensitivity of the material. In fact, the addition of PCMs (or other soft inclusions) enhances the cracking resistance as compared to a plain cement paste or composites containing equivalent dosages of (stiff) quartz inclusions. This is because composites containing soft inclusions demonstrate benefits resulting from crack blunting and deflection, and improved stress relaxation. As a result, although the tensile stress at failure remains similar, the time to failure (i.e., macroscopic cracking) of PCM-containing composites is considerably extended. More generally, the outcomes indicate that dosages of soft(er) inclusions, and the resulting decrease in compressive strength does not amplify the cracking risk of cementitious composites.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1394525
- Journal Information:
- Materials & Design, Journal Name: Materials & Design Journal Issue: C Vol. 132; ISSN 0264-1275
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
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