Abstract
This paper reports results of an investigation carried out to evaluate permeability, porosity and the corrosion resisting characteristics of fly ash concrete made with finely graded beach/dune sand and crushed limestone (typical aggregates used in the Arabian Gulf countries). The experimental program was designed to include concretes made with water-cement ratios in the range of 0.35 to 0.55. The effect of fly ash addition on the water permeability, porosity, and pulse velocity was studied over a period of one year. Accelerated corrosion tests were carried out in the laboratory for a period of about 4 years to study the corrosion resisting characteristics of these concrete mixes. Specimens were located in the exposure site to evaluate the effect of salt contamination on the corrosion of rebars in fly ash concrete. Time to cracking, weight loss of rebars and pH measurements were also carried out on these specimens. Results show that fly ash incorporation in concrete improves its general quality. Fly ash concretes show significantly better performance than plain cement concrete mixes in terms of resistance against rebar corrosion. Also, fly ash concrete specimens contaminated with salts do not show a noticeable aggravation in the rebar corrosion process for 20 percent replacement and for a 9-month exposure period. Reaction between fly ash and calcium hydroxide does not reduce the pH value below the pH of pure saturated Ca(OH) 2 solution (12.5) even after partial consumption of the calcium hydroxide by fly ash.
Original language | English |
---|---|
Title of host publication | Fly Ash, Silica Fume, Slag, and Natural Pozzolans in Concrete |
Subtitle of host publication | Proceedings - 3rd International Conference |
Editors | V.M. Malhotra |
Publisher | American Concrete Institute |
Pages | 295-313 |
Number of pages | 19 |
ISBN (Electronic) | 9780870316128 |
State | Published - 1 May 1989 |
Publication series
Name | American Concrete Institute, ACI Special Publication |
---|---|
Volume | SP-114 |
ISSN (Print) | 0193-2527 |
Bibliographical note
Publisher Copyright:© 1989 American Concrete Institute. All rights reserved.
Keywords
- Aggregates
- Alkalinity
- Concretes
- Corrosion resistance
- Fly ash
- Penneability
- Porosity
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- General Materials Science