Acoustic emission monitoring of crack formation during alkali silica reactivity accelerated mortar bar test
Result description
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.
Keywords
Backscattered electron imagingAcoustic emissionUltrasonic soundingAccelerated expansion testAlkali-silica reaction
The result's identifiers
Result code in IS VaVaI
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Acoustic emission monitoring of crack formation during alkali silica reactivity accelerated mortar bar test
Original language description
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.
Czech name
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Czech description
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Classification
Type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
GAP104/12/0915: Quantitative analysis of quartz deformation affecting ASR in concrete
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Engineering Geology
ISSN
0013-7952
e-ISSN
—
Volume of the periodical
220
Issue of the periodical within the volume
MARCH
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
8
Pages from-to
175-182
UT code for WoS article
000398872200017
EID of the result in the Scopus database
2-s2.0-85013243629
Basic information
Result type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
OECD FORD
Geology
Year of implementation
2017