2nd Croatian Conference on Earthquake Engineering 2CroCEE

More and more buildings need to be repaired and strengthened, both for durability and for the effects of natural disasters such as earthquakes. The repair material should ensure compatibility with the subgrade materials and contribute to their improvement. The continuous development of materials has led to their excellent properties and application possibilities. In addition, the new generation of materials offers more environmentally friendly solutions, which is certainly in line with repair as part of sustainable development. In an effort to meet all these requirements, the use of mortars with exceptional properties and environmental efficiency can be the key to the solution in repair work.
Materials such as ultra-high performance concrete (UHPC) are characterized by exceptional mechanical and durability properties. In its usual composition, it contains large amounts of cement, which can be reduced by using waste materials to improve its environmental performance. One of the properties of UHPC worth highlighting is its toughness, which is achieved by using fibres that ensure a cement composite with a ductile behaviour. However, several factors must be considered for successful use of fibres: Fibre type, dosage and geometric properties. Moreover, to improve environmental performance, waste fibres could replace industrial fibres. Therefore, in this paper a general overview of UHPC and the possibility of its application as a repair material is given. In the second part, an experimental work on the development of UHPC as a repair material is presented. The supplementary cementitious materials (metakaolin and limestone filler) and waste fibres are used in the composition.

Keywords: repair, UHPC, waste materials