Title: Pull-out Tests on Steel Embedments in Concrete
Author(s): T. Balough, G. Kovacshazy and A. Frigey
Publication: Symposium Paper
Appears on pages(s): 221-234
Keywords: anchors (fasteners); concretes; embedment; loads (forces); pullout tests; Structural Research
Sixty-six pullout tests were conducted on cast-in-place concrete anchors consisting of a threaded rod with a washer and two nuts, nonsymmetrical deformed anchors, and formed anchor heads. The purpose of the test program was to compare the behavior of these three anchors and to check the reliability of the ACI 349-85 standard calculation method. All the anchors were cast in 300 x 300 x 150 mm unreinforced concrete blocks. The test variables were concrete strength, embedment depth and edge distance. The test results showed that if the failure mode is a concrete shear cone failure, the values calculated using the ACI 349-85 standard calculation method, without a strength reduction factor, will provide a good prediction. If splitting or pullout failure occurs, the pullout force will be 25 percent lower. The effect of anchorage depth is overestimated by the ACI 349-85 standard model. A strength reduction factor = 0.50 is proposed to achieve a 95 percent probability that failure loads for steel embedment will exceed the ACI 349-85 theoretical value. Formed anchor heads are recommended as a standard.