STEEL-FIBER-REINFORCED WET-MIX SHOTCRETE - COMPARISONS WITH CAST CONCRETE

AS part of a larger investigation in steel-fiber-reinforced wet-mix shotcrete, companion specimens were cast using the shotcrete mixes for a direct comparison with shotcrete after hardening. Deformed steel fibers with five different geometries were investigated. Mixes were first shot on wooden form sand then cast using external vibration. Comparisons were made between shotcrete and cast concrete on the basis of compressive and flexural strengths and the flexural toughness. For a given mix, the average compressive strength of cast concrete was found to be significantly higher than that of the shotcrete. Flexural strengths, however, witnessed a reversal in the trend. In the case of flexural toughness, although the results for cast concrete were decisively different from that of shotcrete, no clear trend became apparent. The paper concludes that care should be exercised in predicting the behavior of shotcrete on the basis of the performance of cast concretes of similar proportions.