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Showing 1 to 20 of 21 for “"Concrete deterioration"”.
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Expansive mineral growth and concrete deterioration: a microstructural and microanalytical study
… the role of newly-formed minerals in premature deterioration of highway concrete, a three-phase study was undertaken. In the first phase, petrographic and SEM/EDAX analyses were performed to determine chemical and mineralogical changes in the aggregate and cement paste of samples taken from Iowa …
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Concrete deterioration inspection system for extending the operating life of nuclear power plants
… which will potentially affect the reinforced concrete structures of a nuclear power generation facility during and beyond its original design life. This task was undertaken in consideration of the feasibility of extending the life of nuclear power plants beyond their current license expiration …
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Maintenance-based design of concrete parking structures
… what type of preventative maintenance for a concrete parking structure will produce the maximum economic benefit. Existing models for concrete deterioration are analyzed for their accuracy in predicting the service lives of concrete structures and a model appropriate for concrete parking …
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Hydrodemolition for concrete removal in bridge rehabilitation
… the use of a high pressure water-jet to remove concrete. It is a new method of concrete removal which is becoming increasing specified by state Departments of Transportation for bridge rehabilitation work. The technical, financial and contractual aspects of using hydrodemolition are examined and …
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Review of current practices to reduce reinforcement corrosion in concrete structures managed by the City of Cape Town
The repair and maintenance of ageing reinforced concrete (RC) structures has become increasingly costly, especially in the Cape Peninsula. Protection and maintenance of these reinforced concrete structures against concrete deterioration and rebar corrosion have become far more important for road …
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The deterioration of concrete by heterothrophic bacteria and fungi
… and develop a novel decontamination process for concrete, which could harness the deteriorative effect of various microorganisms found within the natural environment by a process known as biodecontamination. Whilst the majority of existing research into concrete deterioration has focused on the …
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Structural performance evaluation of the Postrite post-treatment corrosion inhibitor system
… these bridges is associated with bridge deck deterioration. Chlorides are the primary cause of reinforced concrete deterioration in marine environments and areas of deicing salt usage. The chlorides penetrate the concrete and initiate corrosion of the reinforcing steel. A proven corrosion …
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Physical Sulphate Attack on Concrete
Field experience with concrete exposed to sulphates has often shown that concrete can suffer from surface scaling above the ground level caused by physical sulphate attack. This type of attack has been ignored and, in some instances, confused with chemical sulphate attack. In addition, current …
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Influence of substrate moisture preparation on concrete overlay bond strength
… the years in understanding the fundamentals of concrete composition and performance in both safe and harsh environments. Nevertheless, premature concrete deterioration remains a concern and is often experienced either due to poor workmanship or design. The bonded concrete overlay technique has …
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Moisture Conditions and Frost Resistance of Concrete in Hydraulic Structures
… action may have a considerable impact on the deterioration of concrete. Both superficial and internal damage, which are suspected to have been caused by frost action, have been found in concrete in hydraulic structures. These observations have raised questions about the long-term behaviour of …
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Flexural distress and degradation mechanisms in pretensioned concrete beams and railroad crossties
… component of ballasted railroad track and concrete is a commonly used material for crossties in demanding locations such as heavy axle load (HAL) freight railroads, high-speed rail lines, and rail transit systems. Concrete crossties are often designed as prestressed concrete beams, but …
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Residual strength of corroded reinforced concrete beams.
… is focused on the corrosion of reinforcement in concrete members. However, none addresses the problems associated with the residual strength of reinforced concrete beams exhibiting both main and shear reinforcement corrosion simultaneously. The aim of this research, therefore, was to determine …
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Residual flexural strength of corroded AASHTO TYPE II pretensioned concrete girder-deck system
<p>Precast-prestressed concrete (PC) girders are among the most cost-effective type of girders used on highway bridges. Unfortunately, in corrosive environments, corrosion of strands may result in cracking or spalling of concrete, cross-section loss of strands and degradation of material …
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An analysis of the predominant causes of deterioration of concrete structures in South Africa
Concrete deteriorates due to, but not limited to the ingress of deleterious substances which react with the cement matrix, reinforcing bars corrosion, mechanical effects, physical effects, structural damages, poor construction practices. All these factors individually or combined, ultimately reduce …
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Using cathodic protection to control corrosion of reinforced concrete structures
… (CP) has been increasingly used on reinforced concrete structures to protect steel reinforcement from corrosion. However, due to the complexity of environmental conditions, the specifications in national and international standards are still open to discussion in engineering practices for their …
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Influencia de las condiciones de curado en el comportamiento del hormigón sometido a ciclos hielo-deshielo
… Freeze–thaw process is one of the main causes of concrete degradation in cold regions. In central and eastern Europe, the climatic conditions in the winter season are particularly severe for concrete construction. The successive freezing/thawing cycles cause both external and internal concrete …
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A Laboratory and Field Study of Composite Piles for Bridge Substructures
… piles are made of materials such as steel, concrete, and timber. Problems associated with use of these traditional pile materials in harsh marine environments include steel corrosion, concrete deterioration, and marine borer attack on timber piles. It has been estimated that the U.S. spends …
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Damage of concrete with epoxy coated reinforcement due to corrosion, freeze-thaw and fatigue with application to bridge decks
The deterioration of reinforced concrete bridge decks due to corrosion of the steel bars is a common problem. Epoxy coated reinforcement (ECR) is known to perform better than plain (black) steel, but the appropriate maintenance schedule for ECR bridge decks is not well established. The goal of this …
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Deterioro del hormigón sometido a ensayos acelerados de hielo-deshielo en presencia de cloruros
… frente a ciclos de hielo-deshielo. 1. ABSTRACT Concrete deterioration due to freeze-thaw cycles in the presence of de-icing salts is a frequent cause of problems in concrete bridges and other civil infrastructures in Europe. Concrete damage generated by freeze-thaw cycles can be internal, mainly …
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