ACI Global Home Middle East Region Portal Western Europe Region Portal
Email Address is required Invalid Email Address
In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Learn More
Become an ACI Member
Topics In Concrete
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Showing 1-5 of 71 Abstracts search results
Document:
SP126
Date:
August 1, 1991
Author(s):
V M Malhotra
Publication:
Symposium Papers
Volume:
126
Abstract:
SP-126 In August 1991 the Canada Centre for Mineral and Energy Technology (CANMET) in association with the American Concrete Institute; the Institute for Research in Construction/ National Research Council, Ottawa; and the Eastern Ontario and Quebec Chapter of American Concrete Institute sponsored the 2nd CANMET/ACI International Conference on Durability of Concrete. More than 100 papers from 20 countries were received and peer reviewed in accordance with the policies of the American Concrete Institute. Seventy were accepted for publication. The accepted papers are published in two volumes.
DOI:
10.14359/14158
SP126-16
Harold Roper and Daksh Baweja
Corrosion of steel reinforcement within concrete structural elements is a major problem in both research and practice. Laboratory studies have been conducted on fundamental mechanisms of corrosion within concrete in the presence of high chloride and others under conditions of reduced alkalinity. However, little has been published on the interactive effects of these two conditions and the ways in which corrosion rates of steel in concrete are thereby influenced. These two conditions occur concurrently under many practical environmental exposures. This paper presents data on methodology used to determine corrosion rates of steel in concrete. Information on corrosion activities in both carbonated and high-chloride environments is presented with reference to mechanisms involved in breakdown of steel passivation. Interactive effects of the two conditions are examined for a range of concrete types and grades. The data suggest that for normal reinforced concrete structural elements, the interactive effects of carbonation and chloride ion ingress lead to much more rapid corrosion than where the two phenomena occur independently. The interactive effects of carbonation and chloride ions as they influence concretes under service conditions are discussed. In particular, the reduction of carbonation rate in the presence of high-chloride ion concentrations is noted.
10.14359/2177
SP126-69
V. Nobokshchenov
A survey was conducted of failures of prestressing steel in bridge members exposed to potentially aggressive environments. It appears that the main cause of corrosion of prestressing tendons is the ingress of moisture laden with corrosion-inducing agents. Moisture can make its way to the prestressing steel by penetrating through leaking joints from a deck slab, or by diffusion from the underside of a bridge. Moisture may penetrate through concrete cover, sheathing and grout (or grease in unbonded tendons), as well as through anchorage systems. The rate of penetration of moisture depends primarily on permeability of concrete, type of sheath employed for protection of a tendon, and condition of grout or grease inside the sheath. Brittle fracture of reinforcing steel can occur due to pitting corrosion and/or stress corrosion cracking (SCC). Two types of SCC have been identified in prestressing steel in bridges: hydrogen embrittlement and fatigue corrosion. The rate of corrosion in prestressed concrete components can be minimized by using proper preventive and remedial measures.
10.14359/3755
SP126-70
M. Marosszeky, J. G. Yu, and C. M. Ng
Discusses the findings from the study of bond that forms a part of a major laboratory evaluation of the characteristics of repair materials carried out in the Building Research Centre. The important properties of repair patching materials that can affect the bond of a repair, such as shrinkage, thermal movement, compressive, shear, and tensile strength, are evaluated. The importance of surface preparation is also discussed.
10.14359/3765
SP126-30
A. K. Mullick, C. Rajikumar, and N. K. Jain
The task of providing durable concrete for the construction of industrial structures is complex, not only because the service environment, which is man-made, varies from one industry to another, but quite often because of a combination of a large number of causative, promoting, and accelerating factors. Results of a condition survey conducted on a large number of concrete structures in chemical, fertilizer, and petrochemical industries in India are presented. A multidisciplinary approach to investigating the causes of deterioration involving laboratory and in situ tests, is described, with the help of care studies. Since no specific guidance is available in the relevant codes of practice, a broad classification both in terms of the mechanism and kinetics of deterioration is suggested for such created environments for the design and construction specifications of concrete structures. Methods of protection through structural detailing, workmanship, and materials technology are also outlined.
10.14359/3775
Results Per Page 5 10 15 20 25 50 100
Edit Module Settings to define Page Content Reviewer