Sustainable maintenance of a UK trunk road using crack and ex situ cold mix recycling - a case study

TRL's research since the early 1990s has led to crack, seat and overlay (CSO) becoming an established technique for the cost-effective rehabilitation of flexible composite roads in the UK. The treatment does, however, require exposure of the underlying lean concrete base and placement of a new hot mix asphalt overlay which results in the transportation and disposal of large amounts of asphalt planings. When Cemex UK won an Early Contractor Involvement contract for a major CSO maintenance scheme on the A46 trunk road in Warwickshire, an opportunity existed to improve the sustainability of the proposed maintenance treatment by incorporating VicFoam cold recycled base material (CRBM) within the new overlay. With TRL's assistance, Cemex produced an innovative design for the pavement which utilised both crack and seat and ViaFoam which would be produced in an ex situ process using their mobile plant and utilising the asphalt planings arising from the crack and seat phases of the scheme. It is believed that this is the first time in the UK that a CRBM has been used in conjunction with CSO of a flexible composite pavement. This paper presents a case study of the design, construction and in-service performance of the scheme. This includes the considerations employed when using the combination of two techniques with differing design procedures and the observations and measurements taken during construction. An estimation of the carbon dioxide savings made when compared with more conventional maintenance methods has also been made. The findings of a TRL investigation into the condition of the pavement after one year are provided together with suggestions for future performance monitoring of the site.

• Authors:
  • LANGDALE, P
  • CARSWELL, I
  • MCHUGH, T
  • ASHFIELD, M
• Publication Date: 2009

Language

• English

Media Info

• Pagination: CR012
• Serial:
  • TRL STAFF PAPERS
  • Publisher: TRL

Subject/Index Terms

• TRT Terms: Air quality management; Arterial highways; Cold coated materials; Cold in-place recycling; Cracking; Maintenance; Recycling; Repairing; Sustainable development
• Geographic Terms: United Kingdom
• ITRD Terms: 4988: Cold coated material; 4591: Cold in situ recycling; 5211: Cracking; 2433: Emission control; 2748: Main road; 3847: Maintenance; 3635: Repair; 2427: Sustainability; 8119: United Kingdom
• Subject Areas: Highways; Maintenance and Preservation; I31: Bituminous Binders and Materials; I61: Equipment and Maintenance Methods;

Filing Info

• Accession Number: 01144075
• Record Type: Publication
• Source Agency: TRL
• Files: ITRD
• Created Date: Nov 16 2009 12:25PM