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Fracture and permeability characteristics of thermally degraded concrete.

Aboul-Nour, Louay Abdel-Razek (1988) Fracture and permeability characteristics of thermally degraded concrete. Masters thesis, King Fahd University of Petroleum and Minerals.

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This study has been motivated by the premature and accelerated corrosion of bridge decks in the Eastern Province region of Saudi Arabia, where chloride profiles have indicated severe gradients of chloride ions. What has been perplexing is the rapid breakdown of the concrete structure, leading to very high levels of chloride ingress. One of the main causes leading to this rapid breakdown of concrete resistance to chloride ingress is due to the Thermal Incompatibility of Concrete Constituents (TICC) phenomenon. In this effect, diurnal and seasonal temperature changes lead to internal stresses and subsequent microcraking in the concrete expansion of aggregate and paste. The influence of TICC on concrete deterioration was obtained by studying variation in fracture toughness, permeability, and flexural strength of thermally cycled specimens. Also flexural strength tests and coefficients of thermal expansion of Riyadh aggregate and its concrete were determined. The cycling itself consisted of heating specimens to 80 C for six hours, followed by cooling to room temperature for another six hours. Several variables were considered, including influence of aggregate type, mix design, specimen prestress, alternate wetting and drying, and admixtures such as latex and superplasticezers. In addition, permeability characteristics of naturally cycled concrete were also studied. Results show that although strength is insensitive to TICC cracking at first, there is an immediate loss of resistance to permeability and fracture toughness, indicating the greater relevance of the latter parameters of TICC characterization of concrete rather than strength. Other interesting results include severe detrimental effect of TICC on initially stressed specimens and the beneficial influence of admixtures in reducing the adverse TICC effect.



Item Type:Thesis (Masters)
Date:1988
Date Type:Completion
Subjects:Civil Engineering
Divisions:College Of Engineering Sciences > Civil Engineering Dept
Creators:Aboul-Nour, Louay Abdel-Razek
Committee Advisor:Baluch, Mohammed H.
Committee Members:Azad, Abul Kalam and Al-Mandil, M. Y.
ID Code:9531
Deposited By:KFUPM ePrints Admin
Deposited On:22 Jun 2008 16:42
Last Modified:25 Apr 2011 08:58

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