Restrained shrinkage cracking of amorphous metallic fibre-reinforced concrete

In this study, the cracking characteristics of amorphous metallic fibre (AMF)-reinforced concrete, due to restrained drying shrinkage, were experimentally investigated. Three types of test were carried out to investigate the effect of the fibres on the free and drying shrinkage of concrete: free drying shrinkage test, ring shrinkage test and slab shrinkage test. The fibre volume fractions used in the test were 0·2% and 0·4% for ring specimens, and 0·2%, 0·4% and 0·6% for slab specimens. Based on the results of the free drying shrinkage test, it was found that the addition of AMF into concrete could significantly reduce the free drying shrinkage: when using AMF-reinforced concrete, free drying shrinkage was reduced by 24%. In addition, in the test results of the restraint shrinkage tests (ring and slab types), crack development time was delayed from 5 to 7 d, and crack width was reduced to from 36·5% to approximately 74·6%, according to the fibre volume fraction. Thus, AMF can be used to improve the shrinkage cracking performance of concrete.