DEVELOPMENT OF A GENERAL-MODEL OF AGGREGATE REBOUND FOR DRY-MIX SHOTCRETE - (PART II)

A mechanical model previously developed is briefly described and linke d to particle velocity versus size relationships experimentally obtain ed, allowing prediction of the energy of rebound of an aggregate parti cle during shooting. In addition, a failure criterion, based on the wo rk necessary to debond a pal-tide, is introduced in order to allow cal culating the probability of rebound. The model shows good agreement wi th the experimental data in terms of predicting not only the overall r ate of rebound but also its composition. This model provides a novel i nsight into the mechanisms involved in dry-mix shotcrete aggregate reb ound and offers rational explanations to its dependence on aggregate s ize, cement content, shooting consistency and presence of silica fume.