Screw Penetration Testing with the ProSTUD

Transcription

1 Screw Penetration Testing with the ProSTUD 24 June 2010 Structural Testing and Research Inc. 498 Eagle St. N., Unit 6 Cambridge, ON, Canada, N3H 1C2 Tel: (519)

2 STaR Technical Report No: Screw Penetration Testing with the ProSTUD Report submitted to: DMFCWBS, LLC 9100 Centre Pointe Dr Ste 210 West Chester, OH Report authorized by: Steven R. Fox, PhD, P.Eng. President STRUCTURAL TESTING AND RESEARCH INC. 498 Eagle St. N., Unit 6 Cambridge, ON, Canada, N3H 1C2 Tel: (519) sfox@starlabs.ca 24 June 2010 Notice: This report cannot be altered except by STaR, and must be referenced or reproduced only in its entirety. This report is based on the test material and technical information provided to STaR by the Client, for which STaR does not assume any liability. June 2010

3 Screw Penetration Testing with the ProSTUD 1 Objective The objective of the program described in this report was to conduct the screw penetration tests defined in ASTM C with the ProSTUD steel stud manufactured by DMFCWBS, LLC. 2 Test Specimens 2.1 Steel Studs The ProSTUD cold-formed steel stud is a C-section member with standard overall dimensions but with additional stiffeners added to the cross section. The photograph in Figure 2-1 shows a ProSTUD product. The stud size used in these tests was 3-5/8 deep with a 1-1/4 wide flange. ProSTUD is manufactured by both CLARKWESTERN Building Systems and Dietrich Metal Framing. Listed in Table 2-1 are the product designators used by each company and the thicknesses of studs tested. Figure 2-1: Photograph of the ProSTUD Page 3 of 6

4 Table 2-1: ProSTUD Designators and Thicknesses CLARWESTERN Building Systems Designator Dietrich Metal Framing Designator Base Steel Minimum Thickness Base Steel Thickness (in) ProSTUD 25 ProSTUD mil ProSTUD 22 ProSTUD mil ProSTUD 20 ProSTUD 20DW 22 mil ProSTUD 20HD ProSTUD 20STR 26 mil ProSTUD 30MIL ProSTUD 30MIL 30 mil ProSTUD 33MIL ProSTUD 33MIL 33 mil Materials and Equipment Screws: #6 x 1-1/4 Type S bugle head drywall screw, distributed by Grabber Construction Products, ICC-ES ER Sheathing Material: 5/8 Type X gypsum board produced by National Gypsum. Paper Joint Tape: Four pieces of paper joint tape produced by CGC, 2 x 2 square, with a measured thickness of in. Screw gun: Dewalt Model 272, 4000 rpm. Timing device: Stop watch capable of reading to 0.01s. 2.3 Product Sampling The ProSTUD specimens were manufactured for DMFCWBS, LLC by CLARKWESTERN Building Systems in their Pendergrass, GA plant (for the 15, 22, 26, and 33 mil specimens) and by Dietrich Metal Framing in their Hammond, IN plant (for the 18 and 30 mil specimens). The samples were shipped to STaR s facility in Cambridge, ON for testing. A representative of STaR was present when the test specimens were manufactured. The gypsum board was manufactured by National Gypsum and shipped directly from their plant. The screws and drywall tape were purchased by STaR from a local retailer. 3 Test Procedure and Results 3.1 Test Procedure ASTM C645 The test procedure described in ASTM C Standard Specification for Nonstructural Steel Framing Members, Section 10, Penetration Test, was followed. The test specimen was prepared by positioning a 6 x 6 gypsum board sample on an 18 in. length of stud. Four pieces of drywall tape, two inches square, were placed on the gypsum board under the location of the screw. The stud was clamped to the test frame at the center of the web so as not to restrain the rotation of the flange. The test frame allowed the screw gun to drive the screw vertically under its own weight. Additional mass was added to the screw gun so that its total weight was 30 lb, which was verified using a calibrated load cell. Page 4 of 6

5 To begin the test, the technician started the screw gun and slowly lowered it until the screw point was in contact with the Kraft paper. When everything was ready, the screw gun was released and allowed to drive the screw into the board under its own weight (total 30 lbs). The screw gun included an adjustable nose cone that disengaged the gun from the screw at a specific depth allowing the technician to set how far the screw was driven into the board. The time from when the screw gun was released until the screw head was driven below the surface of the board was measured. After the test was complete, the specimen was removed and the technician verified the screw tightness by hand using a screw driver: if the screw had spun out, it could easily be determined in this manner. The data recorded was the time taken to drive the screw and whether there was spin out. 3.2 Test Results and Pass/Fail Interpretation The pass/fail requirements in ASTM C are as follows: Five specimens of each type shall be tested. Members shall be capable of pulling the head of the screw below the surface of the gypsum board in less than 2s without spin out. If more than one specimen fails to meet the requirements, two more test specimens shall be chosen for retesting. Listed in Table 3-1 are the individual test results giving the time taken to drive the screws and whether there was spin out. On two occasions the screw point was defective and the screw would not penetrate the stud: these results were discarded. The photograph in Figure 3-1 shows one of the tested specimens. Table 3-1 Test Data ProSTUD Thickness (mils) Specimen #1 Specimen #2 Specimen #3 Specimen #4 Specimen #5 Time (s) Time (s) Time (s) Time (s) Time (s) Average time (s) Pass/Fail Pass Pass Pass Pass Pass Pass Page 5 of 6

6 Figure 3-1: Completed ProSTUD Screw Penetration Test 4 Conclusions The ProSTUD cold-formed steel framing members in the thicknesses tested successfully passed the screw penetration test as defined in ASTM C Referenced Documents ASTM C Standard Specification for Nonstructural Steel Framing Members, ASTM International, West Conshohocken, PA. Page 6 of 6