GRP pipes are a concrete answer for the Waterford Bridge in Eire

Citation

(1999), "GRP pipes are a concrete answer for the Waterford Bridge in Eire", Anti-Corrosion Methods and Materials, Vol. 46 No. 3. https://doi.org/10.1108/acmm.1999.12846cab.016

GRP pipes are a concrete answer for the Waterford Bridge in Eire

GRP pipes are a concrete answer for the Waterford Bridge in Eire

Keywords Bridges, Concrete, Johnston Pipes, Plastics

A novel use for Johnston's GRP (glass reinforced plastic) pipes has been found to solve an engineering problem on a bridge section in the Waterford River, Waterford, Eire (Plate 3).

Plate 3 Johnston Pipes' standard 6m length GRP pipes and joints enveloping the steel piles supporting Waterford Bridge

When concrete rings protecting the support structure of the bridge were found to have deteriorated and allowed sea water to come into contact with the piles they encased, the civil engineers in charge of its renovation faced a dilemma. Jons Civil Engineering of Duleek, Co. Meath needed a product which would not only withstand the aggressive seawater and tidal action, but would also reduce installation time and cost.

The answer came in the form of 1,400 metres of standard 6m length GRP pipes and joints which were used to envelop the steel piles supporting the bridge from the river bed. The annular space was infilled with concrete grout.

Said John Pentony of Jons Civil Engineering: "The DN 900mm GRP pipes which we used were ideal for the project for several reasons. Their durability has been proven a number of times in similar applications and their smooth surface resists any marine growth, thus reducing the risk of damage to the pipes by biological growth action. From a design and construction point of view, the pipes we used had a stiffness of 5,000N/m2. These were certainly strong enough to resist pump pressures whilst grouting the annulus, being poured with a 12 metre head."

Owing to the lightweight physical characteristics of GRP pipes, standard cranage was used to lift the 6m-long pipes into place. The length of the pipes also meant fewer joints, dramatically reducing installation time and reducing the possibility of future water ingress.

Further details from Johnston Pipes Ltd. Tel: +44 (0)1952 630300; Fax: +44 (0)1952 503833.