The paper reports about the generation and testing of an air-entrained wate
rjet for concrete demolition applications. Experimental results on concrete
samples impinged by conventional waterjets and the air-waterjet show three
essential features of the material removal process. First, the depth of cu
t is not influenced by the air addition. Second, the entrainment of air sig
nificantly affects the material removal rate. Third, there exists an optimu
m air flow-rate for a maximum material removal rate. Based on results of me
rcury-penetration measurements and acoustic-emission tests, a first phenome
nological model (based on the formation of water slugs due to the air sucti
on) is developed. (C) 2000 Kluwer Academic Publishers.