Abstract
Ultrasonic wave reflection (UWR), well established for the study of stiffening and strength development of cement-based materials, normally uses shear waves (S-waves) because they are sensitive to microstructural development. This study demonstrates possible application of UWR with longitudinal waves (P-waves) using a low impedance buffer for investigating stiffening in hydrating cement paste. The P-wave reflection coefficient was seen to increase modestly as hydration progressed. Also, the P-wave reflection coefficient showed higher values for pastes with lower water to cement ratios, which are primarily attributed to the higher density of low w/c pastes, and similar effects with addition of fly ash and entrained air. Partial debonding between paste and buffer was observed in most pastes at a time that coincided with final set as measured using S-waves; and the debonding appears to be associated with the development of pore water under-pressure that occurs after solidification (due to chemical shrinkage).
Original language | English (US) |
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Pages (from-to) | 987-997 |
Number of pages | 11 |
Journal | Materials and Structures/Materiaux et Constructions |
Volume | 46 |
Issue number | 6 |
DOIs | |
State | Published - Jun 1 2013 |
Externally published | Yes |
Keywords
- Cement paste
- Longitudinal wave
- P-wave
- Setting
- Shrinkage
- Ultrasonic wave reflection
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- Materials Science(all)
- Mechanics of Materials