Title: Anchorage of Bundled Bars Grouted in Ducts

Author(s): Francisco A. Galvis and Juan F. Correal

Publication: Structural Journal

Volume: 115

Issue: 2

Appears on pages(s): 415-424

Keywords: anchorage; bond; bundled bars; precast; reinforcement

DOI: 10.14359/51701280

Date: 3/1/2018

Abstract:
An experimental study was carried out to investigate the effect on the bond strength of the number of bars in a bundle, embedded length, and bar size of bundle bars grouted in ducts for connections of precast concrete elements. The study included 14 pullout tests on two- and three-bar bundles grouted in corrugated strip metal ducts. Yielding of the bars was reached with embedded lengths ranging from 11db to 13db for three-bar bundles and 9db to 11db for two-bar bundles. Results demonstrated that the reduction of contact perimeter due to bundling can be estimated by the maximum perimeter in contact of the bars with the surrounding grout. Moreover, there is a debonding length near the loaded end of the anchored reinforcement that increases with the number of bars per bundle. Based on the experimental results, an anchorage length expression for bundled bars grouted in ducts is proposed.