Overview
Français
ABSTRACT
Fly ash is a residue from coal combustion in thermal power plants. It appears when coal is ground to a fine powder and burnt in a thermal power plant. Due to its physical and chemical characteristics, as a binder or in the shape of granulates, it has become a widely used product in road and rail construction at every stage of earthwork carried out such as embankments, upper layer of the earthworks, capping layer and road sub-base. This article provides an extensive review of the usage possibilities of fly ash in the construction sector while detailing the part played by the particles in the protection of the environment.
Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.
Read the articleAUTHORS
-
Pierre ROSSI: Doctorate in geology. Geotechnical manager of the "Grands Travaux de Terrassement (Razel)" unit.
-
Ludovic GAVOIS: Manager of VINCI Construction's geotechnical department – Terrassement
-
Guy RAOUL: Engineer from the École spéciale des Travaux publics; former Director of GTM Construction - Currently Chairman of the French Earthworks Standardization Committee
INTRODUCTION
The fly ash issue is the subject of three articles:
[C 5 373] this one,
[C 5 374] Although references to recently completed projects are given here, some will be the subject of detailed presentations in the article
[C 5 375]
The use of fly ash in the construction industry, which dates back to the 1960s, is still going strong. For economic reasons, fly ash is used close to production sites, making it an ideal technical solution.
Ash comes from existing stocks, built up during coal mining in France, and, since the closure of mining sites, from the production in thermal power plants of residues from the combustion of imported coals. Annual production of fly ash is around 1.5 million tonnes.
Fly ash –, and in particular silica-alumina ash –, can be used in a wide range of applications, mainly as a binder or aggregate. They are used in road and rail construction, at all stages of earthworks: backfill, upper earthworks platform (pst), subgrade, pavement base, the areas we will be focusing on in this dossier.
Other uses, as constituents of binders and cements, grouts and concretes, are also discussed for information purposes.
Today, most ash production is consumed by concrete and cement manufacturers.
The recovery of fly ash is encouraged, as it is a much better solution – environmentally and economically – than its disposal as waste. Fly ash is a non-hazardous waste, according to current regulations.
The environmental aspect...
The Ultimate Scientific and Technical Reference
This article is included in
Sustainable construction
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Use of industrial by-products – Fly ash
Technical reference documents
Guides and catalogs
Websites
-
ADEME
-
DRIRE
-
EDF – Flame thermal energy – Generation sites in France
...
Events
International Ash Utilization Symposium – Healths aspect of Coal Fly Ash. The International Ash Utilization Symposium is held every 2 years. It is organized by the University of Kentucky Applied Energy Research Center and the U.S. Department of Energy.
-
2nd "Earthworks in Europe" symposium
This 2nd Colloquium will be held in London on June 3-4, 2009. It follows...
Standards and norms
-
French reference standards
- Exécution des terrassements. Classification des matériaux utilisables dans la construction des remblais et des couches de forme d'infrastructure routière. - NF P11-300 - Septembre 1992
- Exécution des terrassements Terminologie. - NF P11-301 - Décembre 1994
- Liants hydrauliques. Ciments courants. Compositions, spécifications et critères...
Regulations
-
Extracts from legislative references
Article L. 511-1 of the French Environment Code. The provisions of this title apply to factories, workshops, warehouses, building sites and, in general, installations operated or owned by any natural or legal person, public or private, which may present dangers or inconveniences either for the convenience of the neighborhood,...
Statistical and economic data
European Commission – Directorate-General for Energy and Transport.
Conventional energies – Coal and oil – EU imports of hard coal from third countries for power plants in 2000-2001.
Ministère de l'Économie, de l'Industrie et de l'Emploi, DGEMP, 24/06/2008.
Coal: main provisional results for 2007. DGEMP/Observatoire de l'énergie. June...
The Ultimate Scientific and Technical Reference
