Title: Acoustic emissions of mortar subjected to freezing and thawing

Author(s): Hisatoshi Shimada, Koji Sakai, and Gerard G. Litvan

Publication: Symposium Paper

Volume: 126

Issue:

Appears on pages(s): 263-278

Keywords: acoustic; amplitude; freeze-thaw durability; mortar; Materials Research

DOI: 10.14359/2159

Date: 8/1/1991

Abstract:
To determine the characteristics of deterioration of concrete under freezing and thawing, acoustic emissions of mortar were measured and analyzed. Acoustic emissions of the ice formation were examined to establish test conditions. In addition, propagation properties of acoustic emissions, such as wave velocity and amplitude, were examined with an acoustic emission (AE) pulser. The test results for water showed that acoustic emissions due to ice formation took place during both thawing and freezing. The test results with mortar showed that most acoustic emissions occur during the freezing and that the number of acoustic emissions does not increase with the number of freezing and thawing cycles. The test also showed that the propagation of acoustic emissions is effected by air content and curing period. Therefore, the propagation properties must be considered to evaluate the frost damage of mortar with acoustic emission events. Further, wave velocity and amplitude measured with an AE pulser decrease as the number of freezing and thawing cycles increase. It is concluded that the wave velocity and amplitude of AE pulse propagation can be used as indicators to evaluate the degree of frost damage of mortar.