ROBOTIC APPLICATION OF HIGH PERFORMANCE THERMAL BARRIERS IN TUNNEL LININGS

Abstract

A new sprayable fire-protection mortar for concrete-lined tunnels from the MBT Underground Construction Group is described. The normal concrete aggregate is replaced by light-weight aggregates. The product contains Portland cement, admixtures and an alkali-free sprayed concrete accelerator. Spray application can be undertaken using the dry or wet process. The wet process pump must be a monopump (screw pump) with rotor and stator. The advantages of the product are increased compressive strength, improved bond to concrete and the ability to have bespoke colours by pigmenting the white version of the product. The fire resistance and thermal barriers of the mortar were tested in the Netherlands. The mortar can be applied using the Logica robotic system.