Swansea STW digester tank strengthening

An ultra high modulus carbon fibre composite, weber.tec force carbon sheet was chosen to strengthen the concrete walls to give increased hoop stress capacity. The tank was emptied to remove the live loads from structure and open cracks were injected with epoxy resin. The surface was prepared and two horizontal bands of carbon fibre sheet were applied using weber.tec force EP primer and weber.tec force EP bonding adhesive.

Two layers of weber.tec force carbon sheet were applied to strengthen the tank against lateral forces. The modulus of elasticity of the sheet is 640 kN/mm2 , a tensile strength of 2650 N/ mm2 and an elongation figure of 0.4%. The carbon fibre was supplied in 300 mm wide rolls with a sacrificial backing sheet allowing ease of application to the pre-applied bonding adhesive. The carbon fibre sheet was overcoated with weber.tec force EP bonding adhesive to fully encapsulate the sheet and protect it from degradation.