Title: Behavior of structural macrosynthetic fiber-reinforced precast, prestressed hollow-core slabs at different flexure-to-shear ratios
Date Published: May - June 2019
Volume: 64
Issue: 3
Page Numbers: 76 - 91
Authors: Pradeep Kankeri, Sameer K. S. Pachalla, Nikesh Thammishetti, and S. Suriya Prakash
https://doi.org/10.15554/pcij64.3-01
Click here to view the full article.
Abstract
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.