Huntsman Advanced Materials hardener specified for coatings on the worlds longest trans-oceanic bridge
Article Type: Industrial news From: Anti-Corrosion Methods and Materials, Volume 56, Issue 2
To meet the very stringent requirements for coatings used on the concrete piers of the longest trans-oceanic bridge in the world, engineers turned to Aradur® 450 hardener from Huntsman Advanced Materials.
The 36 km bridge, which crosses China’s Hangzhou Bay between Shanghai and Ningbo, was designed for a service life of 100 years. This extended life expectancy necessitated the use of concrete primers and sub-coats with the ability to withstand exposure to sea water as well as strong multi-directional tidal currents, moving at speeds of up to 30 km/h (18 miles), waves up to 8 m(26 ft) in height, with occasional typhoons, and earthquakes measuring up to seven on the Richter scale.
Engineers who tested numerous pier coating materials ultimately selected Aradur® 450 hardener from Huntsman as the best product for this challenging project. The high-performance hardener offered the required out-standing adhesion to wet concrete pier surfaces to ensure long-term protection on the sub-sea concrete piers.
Application properties were also ideal. The hardener, combined with resin and an advanced Huntsman accelerator, produced a sprayable coating system with a fast dust dry speed and the ability to subsequently cure quickly under saltwater to support an on-schedule project completion.
The high-solids, solvent-containing epoxy coating system, formulated using Huntsman’s Aradur® 450 modified amine hardener and ACC 3130 accelerator, was applied to the concrete piers in multiple layers.
The curing agent provided for easy mixing of system components, supporting preparation of the primer and sub-coat in the field with an ∼80 min gel time at 23°C. The resulting high-solids coating system was readily sprayed onto piers to a thickness of 40 um for the primer and 250 um for the sub-coat.
According to C.M. Chan, Director of Specialty Components, at Huntsman,“We were proud to be part of the impressive Hangzhou Bay Bridge project team, working in partnership with the engineers who tested the materials and the contractors who applied the Aradur® 450-based coating to the concrete piers.”
When the six-lane Hangzhou Bay Bridge opens to the public in June 2008, the ocean-crossing structure will accommodate as many as 50,000 vehicles each day. The new roadway will cut travel time between Shanghai and Ningbo in half, from 4 h to 2.
More information is available at: www.huntsman.com/advanced_materials
