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
DOI:
10.14359/51718011
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.
Related References:
1. ICC Evaluation Service AC193, “Acceptance Criteria for Mechanical Anchors in Concrete Elements,” Whittier, CA, Feb. 2010.
2. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 520 pp.
3. Olsen, J.; Pregartner, T.; and Lamanna, A. J., “Basis for Design of Screw Anchors in Concrete,” ACI Structural Journal, V. 109, No. 4, July-Aug. 2012, p. 559.
4. Kuenzlen, J. H., “Load-Bearing Behavior of Screw Anchors under Axial Tension,” doctoral thesis, University of Stuttgart, Stuttgart, Germany, 2004. (in German)
5. Fuchs, W.; Eligehausen, R.; and Breen, J., “Concrete Capacity Design (CCD) Approach for Fastening to Concrete,” ACI Structural Journal, V. 92, No. 1, Jan.-Feb. 1995, pp. 73-94.
6. Eligehausen, R.; Mallee, R.; and Silva, J., Anchorage in Concrete Construction, Ernst & Sohn, Berlin, Germany, 2006, 391 pp.
7. ASTM E488/E488M-15, “Standard Test Methods for Strength of Anchors in Concrete Elements,” ASTM International, West Conshohocken, PA, 2015, 20 pp.
8. ACI Committee 355, “Qualification of Post-Installed Mechanical Anchors in Concrete (ACI 355.2-07) and Commentary,” American Concrete Institute, Farmington Hills, MI, 2007, 35 pp.
9. Owen, D. B., “Factors for One-Sided Tolerance Limits and for Variables Sampling Plans,” No. SCR-607. Sandia Corp., Albuquerque, NM, 1963.
10. Eligehausen, R.; Bouska, P.; Cervenka, V.; and Pukl, R., “Size Effect of the Concrete Cone Failure Load of Anchor Bolts,” Fracture Mechanics of Concrete Structures, 1992, pp. 517-525.
11. Cook, R.; Kunz, J.; Fuchs, W.; and Konz, R., “Behavior and Design of Single Adhesive Anchors under Tensile Load in Uncracked Concrete,” ACI Structural Journal, V. 95, No. 1, Jan.-Feb. 1998, pp. 9-26.
12. Tarawneh, A. N., “Behavior and Design of Screw and Adhesive Anchors in Thin Concrete Members,” doctoral dissertation, Clemson University, Clemson, SC, 2019.