Research on influences of fly ash content on mechanical properties of shotcrete

Abstract

Shotcrete technology is a key technology of the New Austrian tunnelling method. Owing to advantages of simple and quick process of construction and strong adaptability, it is an indispensable means of modern tunnel construction. Mixing shotcrete with appropriate amount fly ash not only can reduce the generation of cracks and compensate the shrinkage, but also can improve the shotcrete peace ability and reduce the cost of project construction. Through a given number of tests, we study on the influences of fly ash content on the mechanical properties of shotcrete, i.e., tensile, compressive, flexural strength. The results of experiments show that: the strength indexes of shotcrete decrease gradually with the increase mixing content of fly ash. When the fly ash content is more than 28%, the concrete strength has serious loss. For ordinary shotcrete, it is suggested that the optimum dosage of fly ash should be about 9%.