USE OF FLY-ASH IN ROAD CONSTRUCTION

UTILISATION DES CENDRES VOLANTES EN TECHNIQUE ROUTIERE

At the present time, 34 power plants produce approximately 4000000 t of fly ash per year. Fly ash can be combined with lime to form a binder which sets in the presence of water. The composition of a subbase would be: 91% fly ash, 4% quick lime, 5% industrial gypsum (phosphogypsum). This mixture has a compressive strength of 30 bars at 7 days and 140 bars after one year. When manufactured in a plant, it is compacted with pneumatic-tyred rollers. The composition of a roadbase would be: 0/20 gravel (85%), 12% fly ash, 3% hydrated lime. The grading curve of gravel-ash mixtures is a bolomey curve. The composition of the binder (lime/fly ash = 1/4) is that giving optimum performance, the optimum proportioning being 15%. After one year, gravel-ash mixtures containing some limestone, have the highest strength, approximately 300 bars; with quartzite or siliceous limestone, the strength reaches 250 bars. These values decrease by approximately 16% when the density decreases from 100 to 95% of the optimum density. These gravel-ash mixtures are produced exclusively in mixing plants. Compaction is carried out by means of a heavy vibrating roller followed by a pneumatic-tyred roller. /TRRL/

• Supplemental Notes:
  • This report was presented at the International Symposium on Slags, Cinders, and By-Products, Mons (Belgium), September 101-12, 1975.
• Corporate Authors:

  Laboratoire Central des Ponts et Chausees (LCPC)

  Boulevard Lefebvre 58
  Paris Cedex 15,   France  F-75732
• Authors:
  • Andrieux, P
  • Colombel, J H
• Publication Date: 1976-5-6

Language

• French

Media Info

• Features: Figures; Tables;
• Pagination: p. 73-90
• Serial:
  • Bulletin de Liaison des Lab des Ponts et Chaussees
  • Issue Number: 83
  • Publisher: Laboratoire Central des Ponts et Chausees (LCPC)

Subject/Index Terms

• TRT Terms: Base course (Pavements); Calcium oxide; Chemistry; Compressive strength; Conferences; Density; Fly ash; Gravel; Gypsum; Lime fly ash; Mix design; Mixtures; Physics; Properties of materials; Road construction; Soil stabilization; Stabilized materials; Strength of materials
• Uncontrolled Terms: Use
• Geographic Terms: France
• Old TRIS Terms: Quicklimes
• ITRD Terms: 7165: Chemistry; 8525: Conference; 4580: Fly ash; 8036: France; 4575: Gravel; 4175: Gypsum; 4574: Lime; 4714: Mix design; 9047: Mixture; 6755: Physics; 5925: Properties; 4584: Quick lime; 2961: Roadbase; 3688: Roadbase stabilization; 5544: Strength (mater); 9084: Use
• Subject Areas: Geotechnology; Highways; Materials; I33: Other Materials used in Pavement Layers;

Filing Info

• Accession Number: 00152820
• Record Type: Publication
• Source Agency: Central Laboratory of Bridges & Highways, France
• Report/Paper Numbers: Analytic
• Files: ITRD, TRIS
• Created Date: Jul 2 1977 12:00AM