When we applied a 1 1/2-inch thickness of shotcrete recently we used enough total material to produce about 2 1/4-inch thickness if there had been no rebound. Isn't this excessive?
Probably the thickness of the shotcrete placed has more effect than any other factor on the percentage of loss from rebound The thinner the shotcrete layer, the larger the percentage loss. This appears to be caused by the fact that the highest amount of rebound occurs at the time shotcreting begins, when the shotcrete is impinging on a hard surface. Later, when it is being blown against a shotcrete surface the amount of rebound decreases.