Steelwork Repairs

TI Protective Coatings have the capacity to implement numerous of structural strengthening and refurbishment schemes across the country.

The development of the design of a strengthening scheme always commences with either an assessment of the existing structure or a review of an existing assessment carried out by others. This provides an understanding of the way in which the structure behaves, and the degree of redundancy in the structure. This is used initially to develop the strategy for positioning access scaffolding on the structure. Clearly fixed scaffolds provide the best access to the structure which ensures a high quality finished product and ideally the scaffold should be hung from the structure in order to avoid costly ground supported scaffolds.  It is usually possible to make use of redundant capacity in the structure without resorting to usage restrictions or other specialist measures; however in extreme cases these may be necessary. We have recently installed monitoring equipment on two structures in the Highlands of Scotland, which was used in combination with a series of trigger levels to ensure that the works could be managed so as not to overstress the structure.

The assessment is used to develop the strengthening measures necessary to achieve the aspirational capacity of the structure. Our Designers have extensive experience of the development of strengthening schemes which are cost effective and can be practically achieved. Strengthening is often required in areas which are difficult to access and it is important to consider alternative methods of strengthening which carry the loads around corroded or understrength members. On large, complex structures it is important to work closely with the  Assessment Engineers in order to develop schemes which are not overdesigned. In certain instances a pragmatic approach can be taken to avoid complex strengthening of certain members whereby structures can be managed with a degree of theoretical overstress.

The installation of the strengthening scheme requires extensive information regarding the as-built details of the structure. Again, the provision of a fixed access scaffold allows accurate templating to be undertaken to ensure that plates manufactured off site can be installed during short duration possessions. It is important to ensure that works undertaken during possession are kept to a minimum. Wherever possible, rivets will be replaced with temporary HSFG or TCBs during normal working hours on a hit one miss one basis. Plates will be detailed so that they can be installed without compromising the integrity of the existing structure usually by only connecting new plates through every other rivet hole.

The methodology for removal and replacement of structural sections is carefully reviewed along with our Designers; all structural steel is fabricated off-site in accordance with the scheme drawings. The sections to be replaced are then templated on site to allow the correct spacings for holes centres prior to drilling. All repairs are installed by a team of qualified steel workers who are experienced in the removal of corroded elements and the installation of new steel to Highways structures.

Over the past few years we have successfully completed ‘Design & Build Strengthening Schemes’ in a Principal Contractors Capacity, having both undertaken the works in-house and also having managed sub-contractors to undertake the works.