| Shotcrete is an effective means of ground support if properly applied. The quality of the in-place shotcrete is influenced by the ground conditions, the mix design (material components and proportions), the batching procedures, the method chosen (wet or dry mix), the capacity and condition of the equipment, the specified liner design including the time of installation, and most importantly the experience and skill of the shotcreting crew. The installation procedures especially are important in an underground mining environment where the space is often confined, congested and dark and the mine headings numerous. An improperly balanced shotcrete setup will lead to increased costs and dangerous working conditions. An overview is given of typical mix designs and engineering properties of shotcrete with particular attention paid to silica fume and steel fibre reinforced mixes. A review of equipment necessary for a successful operation is given and economic considerations are outlined. Design methodologies and installation procedures are discussed as pertaining to the mining industry. Differences between shotcrete and concrete as well as the mining and civil engineering fields are explained. A site investigation at Mines Gaspe, Quebec where shotcrete was used for ground support and pillar rehabilitation is examined and the benefits are evaluated. |
