Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313114
Title: A laboratory investigation into the structural performance and mechanical properties of plain and reinforced concrete elements affected by alkali silica reaction.
Author: Majlesi, Yasin.
ISNI:       0000 0001 3617 0640
Awarding Body: Queen Mary, University of London
Current Institution: Queen Mary, University of London
Date of Award: 1994
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Abstract:
The object of this study was to help clarify some of the fundamental problems occurring in plain and reinforced concrete structural elements suffering from the degradation phenomenon of alkali silica reaction. A laboratory based testing programme was used, so that extreme conditions for generating alkali silica reaction could be used which are not readily achieved in actual structures. Special concrete mixes were also used in which the alkali silica reaction occurs within a period of months rather than years so that observation of the properties of the reacted concrete could be taken throughout the reacti ve process. The laboratory tests undertaken are as follows: fresh and hardened behaviour of alkali silica reactive (ASR) model mixes; mechanical properties and expansion behaviour of ASR concrete; structural behaviour of reinforced ASR concrete beams and columns; bond between reinforcement and ASR concrete in prisms and beams; restraint effect of ASR upon plain and reinforced concrete structural elements. This work shows that, ASR causes an unacceptable level of progressive damage to plain and reinforced concrete. The degradation and expansion in plain ASR concrete is higher than that in reinforced concrete. ASR in concrete reduces the strength and elastic modulus; the stiffness of reinforced beams; the axial load and ultimate bending moment capacity of columns; the ultimate bond between concrete and reinforcement. As a result of expansion in non-symmetrically reinforced structural elements, ASR causes either sagging or hogging displacement. The restraint imposed by reinforcement in ASR concrete elements is however beneficial in terms of inhibiting expansion and crack development, and exerting a small degree of post tensioning which generally improves the strength of members. Preloading of ASR concrete also results in an improvement in the mechanical properties. PhD
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.313114  DOI: Not available
Keywords: Material degradation & corrosion & fracture mechanics Materials Biodeterioration Composite materials
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