Written by Kerryn Caulfield, executive Director for Composites Australia Inc.
On the northern side of the Brisbane River, 10 kilometres from the Brisbane central business district and 10 minutes from the Brisbane airport, is a new wharf constructed from next generation composite building materials. Opened at the end of November 2018 by the Hon. Annastacia Palaszczuk MP, Queensland Premier and Minister for Trade, the Pinkenba Wharf is owned and operated by the Wagner Corporation. The wharf is a world first – using composite fibre technology and Wagners’ proprietary Earth Friendly Concrete® (EFC) decking system for bridges, jetties and wharfs.
The new wharf is 252m long and 16m wide and constructed to facilitate seamless automated loading and offloading and direct berthing of cement clinker ships that carry up to 35,000 tonnes of cargo. While built primarily for efficiency and to enable easier access to offshore markets for the Wagner-owned cement plant, the wharf will also be used by third parties and has capacity to accommodate a handimax vessel up to 40,000 tonnes deadweight.
The company believes the Pinkenba Wharf to be the largest composites fibre infrastructure project completed to date anywhere in the world, with the highest capacity, and the largest use of structural fibreglass rebar in Australia in a single job. Executive General Manager for Wagners CFT Pty Ltd
L-R: Joe Wagner, John Wagner, Henry Wagner, the Hon. Annastacia Palaszczuk MP, QLD Premier and Minister for Trade, Neill Wagner and Denis Wagner. Simone D Photography.
Each of the panels consists of:
- Pultruded composite fibre U-girders that provide the tensile beam spanning capacity,
- Geopolymer concrete engaged deck that acts as a compression flange while locking the U-girders together,
- Glass fibre reinforced polymer (GFRP) reinforcing bar in the concrete deck to form a completely non-metallic structure that is risk free for marine exposure,
- Vastly reduced embodied carbon emission compared to conventional steel and concrete materials
The hybrid deck superstructure represents a new approach using high technology building materials to deliver efficient, low maintenance and low co2 emission engineering structures.
Wagners CFT used its pultrusion process to manufacture the proprietary GFRP sections using Electrical-Corrosion Resistant (ECR) type glass because it is high-grade and has excellent strength performance, workability and chemical resistance. The fibres are bound by a vinyl ester resin to provide the best structural solution at an economical cost.
In summary, a total of 517,637kgs of Fibre-Reinforced Plastic (FRP) were used constructing the wharf including: 573 Composite U Girders – 12m long lengths on the jetty and 8.2m long in the wharf, all manufactured in Toowoomba. Over 305 km (152 tonnes) of 16mm, 19mm and 22mm diameter GFRP rebar was used to reinforce the structure. Fourteen 11.7m long FRP light poles were also installed to illuminate the structure.
Compared with traditional materials, the use of FRP and EFC is known to reduce carbon emissions by 74%.
Michael Kemp said the company now has a mature and proven catalogue of composites work in civil infrastructure, and can confidently apply these skills and techniques to highly corrosive marine field conditions.
In a published paper titled “The use of Geopolymer Concrete and GFRP Materials for an innovative wharf structure”, Thomas Glasby et al, EFC Manager, Wagners EFC Pty Ltd, describes the design and construction of the new wharf as follows:
The wharf’s deck is comprised of 191 no. prefabricated panels that span between 8 and 12 metres over steel headstock beams. The panels are a unique hybrid structural system developed over many years by Wagners R&D division initially for use in pedestrian and road bridges. The system has been adapted and further developed for the challenging conditions of a marine wharf structure.
For some time, Composites Australia has been part of a committee working with Standards Australia to develop Australian Technical Specifications for FRP composite rebar. Given the absence of an Australian standard, the GFRP reinforced geopolymer concrete slabs for the Pinkenba Wharf deck units were designed in accordance with Canadian Standard CSA S806 (2012). As explained by Thomas Glasby, this standard outlines methods for manufacturing requirements, designing beams and slabs for ultimate and service loads, testing of reinforcing bars and testing the bar and slab interactions.
According to Michael Kemp: “GFRP has a very important role to play as reinforcement in concrete structures that will be exposed to harsh environmental conditions where traditional steel reinforcement could corrode, especially in marine and other salt laden environments.”
At the forthcoming Advancing Composites Innovation Conference, to be held in Sydney from 2 – 4th April 2019, Michael will present the on the design and manufacture of the Pinkenba Wharf prefabricated deck units and the testing and material properties validation that were undertaken on this structural system and its component materials.
This article first appeared in: Connection Magazine Issue 49: December, 2018