Silts treated for low-volume base courses

This paper present a particular case of a treatment of chalk. Chalk is an evolution rock which produces large quantity of fine elements while pulverised. It is very porous and sensitive to water however it is clay free. A specific binder, LSC (special calcareous binder), was design to treat calcareous materials, in particular chalk. It allows higher strength at long term period than classical cement or road binder. The laboratory studies of chalk treatment are difficult to carry out as it must be as closer as possible to the reality of the site. The usual method employed for clayey and sandy soil cannot be simply applied. An approach of a study methodology is presented to approximate laboratory and site conditions. It emphasises the need to know the final grading of the chalk after pulverising on the site, the water content and the correspondent density in situ. The site of Witry bypass (national road) near Reims, illustrate a chalk treatment for a subgrade. It corresponds to a national road supporting a high level of heavy traffic. Preliminary studies, carried out by using classical study methods, showed insufficient setting of the treated chalk and a high sensitivity to water. The studies, performed by different laboratories (administration, road contractor, cement producer) and using different hydraulic binders, concluded that the LSC binder was the best product. Thus the Consulting Engineer decided to do the treatment of the chalk in high water content conditions and with an excess of binder content so as to minimise the risk of low strength on site considering the laboratory results. The chalk treatment conditions and the monitoring of the site showed the need to modify the organisation of the work: quantity of water to add to a too dry chalk, waiting period before the treatment, working with a very soft and plastic material which forces contractors to level the capping layer one to two days later. Finally the works were checked through deflection and core samplings. They showed the good behaviour of the final platform.

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  • Find a library where document is available. Order URL: http://worldcat.org/isbn/8489875278
• Authors:
  • Abdo, J
  • Puiatti, D
• Conference:
  • International Symposium on Subgrade Stabilisation and In Situ Pavement Recycling Using Cement, 1st, 2001, Salamanca, Spain
• Publication Date: 2001-10

Language

• English

Media Info

• Pagination: 16p
• Monograph Title: First International Symposium on Subgrade Stabilisation and In Situ Pavement Recycling Using Cement, Salamanca, Spain, 1-4 October 2001

Subject/Index Terms

• TRT Terms: Base course (Pavements); Binders; Deflection; Pavement design; Silts; Strength of materials; Traffic flow; Water
• ATRI Terms: Basecourse; Binder; Deflection; Pavement design; Roadbase; Silt; Strength; Traffic flow; Water
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 01392471
• Record Type: Publication
• Source Agency: ARRB
• ISBN: 8489875278
• Files: ATRI
• Created Date: Aug 23 2012 7:09AM