Properties of protective coating applied on concrete bridge

Specific requirements for the repair of construction materials in maritime environment consist of using new materials and technologies. Interesting material for this purpose is fibre reinforced concrete (FRC). Depending on repair requirements different types of FRC are in use. FRC with small percentage of steel fibres has a purpose to decrease shrinkage induced cracking and higher amounts of fibres provide better mechanical properties. Interesting type of FRC is High performance steel fibre reinforced concrete (HPFRC), which is characterized with high strength and modulus of elasticity and low shrinkage as important properties for comparison between the old and new concrete and for load bearing capacity. Other HPFRC properties include low permeability, which is important for durability of constructions in maritime environment. In laboratory, two different mixes are produced. HPFRC was mixed with an addition of new generation of superplastificizer, silica fume and steel fibres. In order to prove the required properties of concrete, laboratory tests are carried out. Efficiency of protective coating can be controlled in-situ with classical methods of concrete powder drilling and chemical analysis and with fibre optical deformation sensors which is embedded in the construction during repair works.