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The influence of aggregate stiffness on the measured and predicted creep behaviour of concrete

A project report submitted to the Faculty of Engineering, University of the
Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the
degree of Master of Science in Engineering.
Johannesburg, 1998 / Aggregate stiffness is known to influence the magnitude of creep of concrete. The
purpose of this research project was to quantify the influence of aggregate stiffness
on the measured and predicted long-term creep behaviour of plain concrete.
Basic and total creep tests were conducted on concrete specimens of two different
strength grades for each of three different commonly used South African aggregate
types (quartzite, granite and andesite). In addition, elastic modulus tests Were
conducted on cores of the aggregate types considered.
The test results revealed that no correlation exists between the creep of concrete
and the stiffness of the included aggregate. These results appear to be attributable
to the stress-strain behaviour of the aggregate/paste interfacial zone, in the case of
aggregates with an elastic modulus in excess of 70 GPa.
The experimental basic and total creep values from this investigation were
compared with those predicted for each mix at the corresponding ages by the BS
8110 (1985), ACI 209 (1992), AS 3600 (1988), CEB-FIP (1970), CEB-FIP
(1978), CEB-FIP (1990) and the RILEM Model B3 (1995). This comparison
indicated that the results predicted by each model vary widely and that no
correlation exists between the magnitude of the aggregate stiffness and the creep
strains predicted by each model. / MT2017

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/22862
Date January 1998
CreatorsFanourakis, George C
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis
FormatOnline resource (232 pages), application/pdf

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