Title: Tensile Behavior and Design of Screw Anchors in Thin Concrete Members

Author(s): Ahmad N. Tarawneh, Brandon E. Ross, and Thomas E. Cousins

Publication: Structural Journal

Volume: 117

Issue: 1

Appears on pages(s): 91-102

Keywords: drilling in concrete; post-installed anchors; sandwich wall panels; screw anchors; thin concrete members

Date: 1/1/2020

Abstract:
This paper presents an experimental program investigating the behavior of single screw anchors embedded in thin concrete members under tension loading. Variables included: concrete thickness, concrete compressive strength, anchor diameter, and anchor manufacturer. Anchors were embedded in the full thickness of the concrete member and the effects of back-face “blowout” due to drilling were considered. The results show that concrete strength, anchor diameter, and anchor brand have a statistically significant influence on the capacity of anchors embedded in 4 in. (102 mm) thick concrete. However, these factors make no significant difference to the capacity of screw anchors in 2 in. (51 mm) thick concrete members. Based on the experimental results, a behavioral and design models are proposed. These models use a reduced embedment depth to address the back-face concrete blowout due to drilling. The proposed model results in levels of accuracy and variability that are consistent with other types of anchorage and the associated models.