Client: Masterton District Council

Designer: WSP

The three span Tauweru Bridge, located on Stonvar Rd, is an important access route to the farming and forestry area east of Masterton. The bridge carries a high volume of traffic, including heavy trucks from the forestry and logging operations, and is an important asset to the Masterton District Council.

In 2018, Contech was awarded a contract to carry out strengthening work designed to increase bridge load capacity to the High Productivity Motor Vehicle loading requirement. The strengthening work included external post-tensioning to bridge beams and carbon FRP to underside of the deck. As part of enabling work a temporary speed restriction was imposed on the bridge for the duration of contract to reduce vibrations from the vehicle traffic.

A pair of unbonded tendons was installed to each side of the two bridge beams. The PT tendons comprised three 15.2mm diameter greased and sheathed strands individually anchored using Contech’s monostrand external anchorage. The FRP work involved installation of the SikaWrap Hex 103C carbon fibre system. Substrate preparation, comprising concrete grinding, uncovered extensive cracking in the bridge deck which, if left untreated, could compromise durability and performance of the carbon FRP. In discussion with the client crack injection work was added to the contract as a variation.

To minimise impact on the construction programme a separate crew was sourced from another Contech branch to carry out this operation. The project was successfully completed on time and as programmed in March 2019.