Number of the records: 1

Acoustic emission monitoring of crack formation during alkali silica\nreactivity accelerated mortar bar test

SYSNO ASEP	0475320
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Acoustic emission monitoring of crack formation during alkali silica reactivity accelerated mortar bar test
Author(s)	Lokajíček, Tomáš (GLU-S)_{RID, SAI, ORCID} Přikryl, R. (CZ) Šachlová, Š. (CZ) Kuchařová, A. (CZ)
Source Title	Engineering Geology. - : Elsevier - ISSN 0013-7952 Roč. 220, MAR 30 (2017), s. 175-182
Number of pages	8 s.
Publication form	Print - P
Language	eng - English
Country	NL - Netherlands
Keywords	Alkali-silica reaction ; accelerated expansion test ; ultrasonic sounding ; acoustic emission ; backscattered electron imaging
Subject RIV	JJ - Other Materials
OECD category	Materials engineering
R&D Projects	GAP104/12/0915 GA ČR - Czech Science Foundation (CSF)
Institutional support	GLU-S - RVO:67985831
UT WOS	000398872200017
EID SCOPUS	85013243629
DOI	10.1016/j.enggeo.2017.02.009
Annotation	System of semi-continuous ultrasonic sounding and acoustic emission (AE) monitoring of experimental mortar bars subjected to ultra-accelerated (14-days lasting) alkali -silica reactivity (ASR) test was developed and assessed for refined interpretation of early stages of reaction. The experiments were carried out by using four different types of crushed stone (quartz from pegmatite, chert, quartzite, quartz-rich metagreywacke) exhibiting variable ASR potential from non-reactive to reactive. By analysing AE characteristics, these faithfully reflect microstructural changes during the first 3-5 days of the test. Early formation of ASR damage phenomena within aggregate particles showing variable ASR potential is accompanied with non-linear interaction of propagating or released acoustic waves. During the second half of the test, rapid attenuation of AE activity, specifically in the case of the two most reactive types of aggregates (quartz metagreywacke and chert), reflects deterioration of the (micro) structure of tested materials and decrease of quality of contacts between steel wave guides and experimental mortar bars. The later fact presents major limitation of current approach during later stages of ultra accelerated mortar bar test. Despite this limitation, ultrasonic sounding and AE monitoring seems to be much more sensitive to early stages of development of brittle damage phenomena due to ASR than standard dilation reading is. This has been confirmed by subsequent direct observation of damage phenomena by backscattered imaging in scanning electron microscope.
Workplace	Institute of Geology
Contact	Jana Popelková, popelkova@gli.cas.cz, Sabina Janíčková, Tel.: 233 087 272
Year of Publishing	2018

Number of the records: 1