Behavior of structural macrosynthetic fiber-reinforced precast, prestressed hollow-core slabs at different flexure-to-shear ratios.

Body text Keywords Body text Review policy Body text Reader comments Body text Prestressed hollow-core slabs are generally precast concrete elements manufactured using an extrusion machine. Although prestressed hollow-core slabs are designed as uncracked members under service loads, cracking is unavoidable under excessive loading. The postcracking behavior of hollow-core slabs can be improved at very low cost by adding structural macrosynthetic fibers during the casting process with no modifications to the mixture proportions of zero-slump concrete. This paper examines the behavior of structural macrosynthetic fiber-reinforced hollow-core slabs at three different shear span-to-depth ratios a/d. Six full-scale tests were conducted on hollow-core slabs, of which three had no fiber additives and three had a polyolefin fiber dosage of 0.33%. The a/d values of 2.5, 3.75, and 7.5 were considered to evaluate the effect of macrofibers on the performance of hollow-core slabs. The test results indicate that the addition of macrosynthetic fibers increased the ultimate strength up to 19% with an increase in ductility. The contribution of fibers in improving the postcracking stiffness was better at higher a/d values under flexure-dominant behavior. Existing analytical models were suitably modified to predict the theoretical capacity of slabs with and without fibers. [ABSTRACT FROM AUTHOR]