Case Study Overview
Essential scour repairs using concrete bagwork to minor road bridge including mortar repairs and repointing to below water areas.
Diving contractor responsible for all health & safety planning and repair work including preparation of Diving Project Plan and Method Statements for forms of repair. Full liaison with client to obtain site access over private land adjacent to structure.
Low water levels precluded use of diving equipment so team reverted to placing bagwork via wading methods, wearing dry suits only. All concrete materials mixed on site and placed into starch lined hessian bags. Bagwork place by hand and secured using steel pins beneath abutment scour areas. Further bags placed and secure in channel as additional scour protection.
At a glance
- Location: Windcross Bridge, Dymock, Gloucestershire
- Date: March 2012
- Project Value: Award Value £11, 244 final outturn £11,758 plus VAT. Increase due to cost of additional materials to carry out further work on site under Site Instruction to deal with extra scour areas reported by R7M
- Programme Duration: 5 days on site including mob/demob, all work included extras completed in 4 days.
- In-House resources Work: All works by R7M personnel – 5 man team
- Contract: Gloucestershire Highways Subcontract Order
The Solution
All scheduled repair work delivered on time and within agreed budget.
Use of starch lined hessian bags to minimise washout of cement in to water course during placing of protective concrete bagwork. Low cost repair solution mitigating use of additional plant ie concrete mixer and pump on highway, road closures etc. Equivalent 5.5t of concrete carefully placed beneath vulnerable areas of bridge structure without use of formwork.
Value Added
Use of local sand/aggregate suppliers for concrete mix for bagwork. Material delivered to site in manageable quantities to ensure no wastage. Additional work carried out within original time budget – extra materials cost only. Minimal pollution of water course. Re survey area at start of job using R7M engineers to confirm extent of defect.
After Work
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