Cemented paste backfill (CPB) technology is now widely utilized by most modern underground hard rock mines in Canada, Australia, the United States, South Africa and Turkey. CPB is a cementitious material produced with three ingredients: filtered wet tailings, hydraulic binders, and mixing water to ensure the paste's flowability in pipeline for final deposition. This book investigates CPB technology using a recently designed lab apparatus called CUAPS (curing under applied pressure system) that estimates in situ CPB conditions. The CUAPS apparatus has been demonstrated as a practical and cost-effective tool that effectively replaces the traditional approach using non-perforated plastic moulds. The results obtained with the CUAPS apparatus will contribute to improve the safety of mines and miners and provide a better understanding of paste backfill. Each section of this book represents an original contribution to the science and engineering of paste backfill. This book provides some theoretical and experimental bases for designing paste backfill mixtures in terms of cost savings and safety and for incorporating in situ backfill behaviour and properties.