ABOUT THE 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.

International Concrete Abstracts Portal

Showing 1-5 of 12 Abstracts search results

Document: 

SP219-05

Date: 

March 1, 2004

Author(s):

H. C. Scott IV and D. L. Gress

Publication:

Symposium Papers

Volume:

219

Abstract:

This study investigated the reactivity of concrete containing recycled concrete aggregates (RCA) that had shown distress due to alkali silica reaction (ASR). The investigation evaluated several mitigation techniques to control ASR in concrete containing potentially reactive RCA. Mitigation work was done with three different aggregate types; an igneous fine-grained quartzite aggregate locally called blue rock, a non-reactive limestone, and RCA containing blue rock aggregate. These aggregates were used to investigate various mitigation techniques to prevent ASR from occurring in concrete containing RCA. The mitigation strategies include the use of class F fly ash, ground granulated blast furnace slag (GGBFS), lithium nitrate, silica fume blended cement and low alkali cement. These materials were incorporated into concrete mixes by cement substitution and direct application. These mitigation strategies showed potential in controlling ASR distress in RCA concrete. Mortar bars and concrete prisms were used to investigate the mitigation strategies by following standard and modified versions of ASTM C 1260 and ASTM C 1293 specifications to evaluate expansion caused by ASR. The modified versions of ASTM C 1260 were found effective in evaluating potential ASR expansion using conventional aggregates.

DOI:

10.14359/13139


Document: 

SP219-11

Date: 

March 1, 2004

Author(s):

A. Tagnit-Hamou and S. Laldji

Publication:

Symposium Papers

Volume:

219

Abstract:

The use of mineral admixtures as addition to or replacement of portland cement has been attracting a great amount of interest in recent years. Using suitable quantities of those minerals not only improves some properties of fresh and dry concrete, but also reduces portland cement demand and helps solve several environmental problems. Aluminium production in various parts of the world generates a considerable amount of waste which contains leachable cyanides and fluorides that cause a serious environmental problem. This paper presents a study of the effect of substituting a percentage of cement by a glass flit in mortar and in concrete. The term glass frit refers to spent pot liners resulting from the aluminium production process, that have undergone various treatments and have been ground to the fineness of a cement. The various results obtained in different tests conducted on mortar and concrete showed that glass frit has a remarkable reactivity potential and an interesting rheological behaviour. Replacing a percentage of cement by glass frit improves workability and strengths of mortar and concrete. For a given slump, concrete containing 25% of glass frit requires 50% less water reducer than that of control concrete. The compressive strengths developed in mortar or in concrete are very similar or even greater than those made with portand cement only or those incorporating blast furnace slag with equivalent cement replacement rate.

DOI:

10.14359/13145


Document: 

SP219-04

Date: 

March 1, 2004

Author(s):

J. S. Melton

Publication:

Symposium Papers

Volume:

219

Abstract:

Recycled concrete aggregate (RCA), when used appropriately, is an excellent substitute for natural aggregates in highway construction. RCA has been used successfully in unbound applications such as base course and fill, and in bound applications as aggregate in new concrete. However, a significant amount of concrete debris is still disposed of in landfills. Barriers to concrete recycling include regulatory and policy issues, economic disincentives, environmental concerns and technical questions. This paper reviews current obstacles to concrete recycling and discusses recent developments and research that will help overcome these barriers.

DOI:

10.14359/13138


Document: 

SP219

Date: 

March 1, 2004

Author(s):

Editors: Tony Liu and Christian Meyer / Sponsored by: ACI Committee 555

Publication:

Symposium Papers

Volume:

219

Abstract:

This publication contains 11 papers which promote and encourage the use of recycled concrete and other materials in concrete construction, taken from presentations at the 2003 ACI Spring Convention in Vancouver, Canada. Specific subject areas include the global perspective, challenges and opportunities of concrete recycling, the barriers to recycling concrete in highway construction, and current practices in the European Union, Japan, and USA. This publication also contains research papers on the use of recycled glass as aggregates for architectural concrete, recycled scrap tire rubber, flowable slurry containing wood ash, recycled latex paint as an admixture, crushed stone dust in production of self-consolidating concrete, a new binder using thermally treated spent pot liners from aluminum smelters, and the durability of concrete containing recycled concrete as aggregates that had shown distress due to alkali-silica reaction. Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP219

DOI:

10.14359/14033


Document: 

SP219-01

Date: 

March 1, 2004

Author(s):

E.K. Lauritzen

Publication:

Symposium Papers

Volume:

219

Abstract:

The paper consists of an overview of the development of techniques for recycling concrete. Demolition, processing and the recycling of the resulting materials are often analyzed separately. "High quality" recycling of concrete waste does not always correspond to production/use of the product with the highest value, but rather the most feasible product in a specific project or region. It is by analyzing the whole disposal/supply-chain, including the substituted material, that the best effects of recycling can be achieved. Overviews of methods for environmental evaluations as well as economic considerations are presented. Integrated demolition waste management in Kosovo and an analysis of the potential market in Hong Kong are presented as examples of the worldwide market for recycled materials. Issues regarding the handling of polluted materials will be discussed from a practical point of view. Moreover, some aspects to soncsider regarding future demolition when producing new concrete products are presented.0

DOI:

10.14359/13134


123

Results Per Page 




Please enter this 5 digit unlock code on the web page.