Title: Early-age shrinkage effects in precast concrete sandwich panels
Date Published: January - February 2020
Volume: 65
Issue: 1
Page Numbers: 74 - 88
Authors: Qian Huang, Ehab Hamed, and R. Ian Gilbert
https://doi.org/10.15554/pcij65.1-04

Click here to view the full article.

Abstract

An experimental study that investigates the shrinkage effects at early ages of five precast concrete sandwich panels with various configurations is presented. Wire strain gauges were embedded within the concrete panels to determine the strain profile in unloaded specimens. The results indicate that the steel reinforcement, the insulation, and the shear connectors in the panels all impose different degrees of restraint to shrinkage of concrete and these parameters can change the shrinkage-induced strains significantly. A two-dimensional finite element analysis (FEA) model that was verified by the experimental results was used to explain aspects of the structural behavior that could not be measured in the tests. The FEA model accounted for creep, shrinkage, and aging of concrete, as well as creep in the insulation, and it used a bilinear shrinkage profile within the thickness of the concrete layers. A parametric study was conducted to investigate key parameters in the design of precast concrete sandwich panels, including the profile of the shrinkage strain, total reinforcement ratio, and diameter of the diagonal-bar shear connectors.