Скачать или смотреть Headed Stud Anchors Installed on the Inside Corner of an Angle

Presented By: Neal Anderson, Simpson Gumpertz and Heger

Description: Most welded headed-stud anchor tests reported in the literature have investigated connections with studs installed normal to the face of the loaded concrete surface. With respect to the embedded plate surface, test loads are applied normal (tension), parallel (shear), or in a combined fashion. The purpose of this investigation was to determine the capacity of headed-stud anchors cast into concrete at an edge where the anchor is at a 45° angle to the horizontal and vertical surfaces. This type of installation is common in many cast-in-place, precast, and tilt-up applications. It is also a common detail for armoring the corner edge of concrete. This program tested four series to determine the headed-stud connection capacity. All headed-stud test specimens consisted of ½ in. dia. x 4 in. (12.7 x 102 mm) long headed studs welded at a 45° angle into the inside corner of a 3 in. x 3 in. x 5/16 in. (76 x 76 x 8 mm) thick structural steel angle. The first test series (Series 1) served as control tests to determine the single-stud capacity. The second and third test series examined a two-stud connection with two separate stud spacings (s1): 5 in. and 9 in. (127 and 230 mm) apart, respectively. The fourth test series (Series 4) was identical to Series 2 with s1 = 5 in. (127 mm), but with the addition of confinement reinforcing steel. Test specimens were cast into an 8 in.-thick (200 mm) slab with a center recess; concrete strength averaged 4,700 psi (32.4 MPa). The observed concrete breakout failure surfaces were similar to those documented in direct tension tests of headed studs near a concrete free edge. The breakout surface closely represents the 35° failure cone model used in current design standards. The single-stud capacity of Series 1 was almost one half the two-stud connection capacity of Series 3 having studs spaced at 9 in. (230 mm) center-to-center.