webercem spray DS prolongs the life of Teesport jetty
20 05 2015
Specialist, high performance concrete repair products by Saint-Gobain Weber have been used by Balfour Beatty Concrete Repairs, part of Balfour Beatty Construction Services UK, (BBCS), in the repair and protection of the bulk handling jetty at Teesport.
Teesport is the biggest deepwater harbour on the east coast of England and therefore a highly strategic commercial port for global freight movement. The jetty operations are particularly important and handle a wide variety of bulk liquid shipments including specialist chemicals and cooking oil. The jetty is owned by PD Ports, a member of the Canadian Brookfield Ports Company.
Regular maintenance inspections had identified increasing levels of deterioration of the reinforced concrete due to the relentless corrosive action of the tidal marine salinity on the reinforcing steel. A remedial plan was developed to carry out repairs and to introduce a cathodic protection (CP) system to greatly enhance the protection level and therefore extend the life of the structure. The plan was prepared by SC Consulting Engineers (SCCE) of Stockton-on-Tees, the structural engineers retained by PD Ports. The contract was awarded to Mansell Build which is now an integral part of BBCS.
Two major factors had to be accommodated within the repair programme. Firstly, the tidal flow that submerged the lower part of the jetty twice in every 24 hours giving a five hour working window, and secondly, the jetty is a live and very active transport hub and shipping schedules had to take precedence at all times.
Saint-Gobain Weber’s repair concrete products were specified for the structural remediation on the Teesport jetty and technical advice was provided for the active application phase of the project. A suspended scaffold was designed and installed which allowed fast access when the tide ebbed so that productivity could be maintained. Hydro-demolition was used to breakout the spalled and cracked concrete and to wash out the surface chlorides and clean the existing steel reinforcement bars.
webercem spray DS is a ready-to-use, polymer modified, cement-based concrete mix with inert limestone aggregates and dust suppressants. It is designed especially for dry process spray application to give high early strength, reduced rebound and maximum application thickness; up to 150mm thickness can be applied in one pass on vertical or overhead faces without any additional mesh reinforcement. webercem spray DS repair concrete is designed for use in conjunction with CP systems and complies with the Highways Agency Specification Class 29F for major structural repairs. The rapid strength development and dimensional stability of webercem spray DS, which can achieve an initial set in 2-3 hours, was especially valuable in the tidal conditions at Teesport.
A CP system using Patchguard® anodes from CPT was installed to protect the steel reinforcement with the anodes fixed into the soffits and webercem spray DS was used to build up a new protective cover for the CP system and for repairs to the concrete structure.
The Teesport jetty project has been completed successfully and John Lees of SCCE, who led the design team, is confident that the jetty protection will extend the working life of the structure. “The products we have used are excellent and the application methods have enabled us to deliver a high degree of protection and reinstatement to the concrete structure. The Weber products, together with the CPT anodes, also provide a 15 year guarantee. PD Ports will carry out a 12 month inspection and then the regular engineers report sequence will follow. The Weber materials have been key to achieving this success.”