Construction and repair with wet-process sprayed concrete and mortar

Purpose of the report The aim of the report is to provide practical guidance for designers, specifiers, contractors and clients on all aspects of low-volume wet-process sprayed mortars and concretes. It provides information on both new construction and small-scale repair and covers choice of application method, materials and mixes, specification, pumping and spraying, finishing, curing, testing and performance. The information is a combination of existing good practice and new knowledge acquired during a recently-completed three-year research project conducted at Loughborough University entitled ‘Wet Process Sprayed Concrete for Repair’. This was funded by both the UK Government (the EPSRC) and industry, namely Balvac Whitley Moran, Fibre Technology, Fosroc International, Gunform International Ltd and Putzmeister UK Ltd. This document concentrates on wet-process mortars and small aggregate concretes (< 8 mm) applied in thin layers (<100 mm) at low/medium output rates (< 5m3/hr), in some cases with mesh or fibre reinforcement. The report uses terminology standardised by the European Federation of National Associations of Specialist Repair Contractors (EFNARC), namely ‘sprayed concrete’, with mixes containing aggregate with a maximum size of 3-4 mm being classed as mortars and anything larger as concretes.