The Second Penang Bridge in Malaysia is a dual carriageway toll bridge that connects Bandar Cassia in Seberang Prai on mainland Peninsular Malaysia with Batu Maung on Penang Island. It is the second bridge to link the island to the mainland after the first Penang Bridge. The total length of the bridge is 24 km, with the section over water being 16.9 km, making it the longest bridge in Southeast Asia.
The Penang Second Bridge is the longest bridge in the world to have been installed with a high damping natural rubber (HDNR) bearing, an effective seismic isolation system that enables the bridge to withstand far-field earthquakes up to a magnitude of 7.5 on the Richter scale. The bridge is the first in Malaysia to be installed with seismic expansion joints, which will allow movements during an earthquake.
Long Lifetime by improving concrete quality
The bridge has been built to last 120 years without major maintenance. To achieve this goal, the concrete was designed with low chloride permeability and a thick cover. As an additional protection measure, deep penetrating hydrophobic impregnation Sikagard-705® L was used to protect the pile caps and 80 MPa spun piles at a total of 180,000 m2 concrete surface area. Sika also supplied Antisol A curing compound, to improve concrete quality.
During construction, there were a number of honeycomb, blow holes, low concrete cover and crack lines at the segmental girders. As a total solution provider, Sika stood tall in providing the right products to rectify the defects and to enhance the durability of the structure.
Total repair for future durability
Cracks were injected with low-viscous epoxy resin Sikadur®. Large honeycombs were remedied using pourable Sika micro concrete with rapid chloride permeability lower than 1,000 coulombs at 28 days to ensure long durability in marine environment. All blow holes were repaired using a two component polymer modified resurfacing mortar SikaTop®-121. For small areas, patch repair mortar Sika MonoTop® was applied.
At the area of low concrete cover, surface-applied corrosion inhibitor Sika FerroGard-903+® was used to protect the reinforced steel bars. Combine protection on concrete surface with 3 to 4 mm of epoxy cement coating, i.e. Sikagard-720 EpoCem was applied to increase the cover, thus enhance durability.
Sika Malaysia’s role in the project was to supply products and, where required, provide the relevant cutting-edge technical advice as well as site product trainings to site personnel on proper use and application of the products.