Patent ID: 8621806
Filing Date: 2014-01-07
Classification: E04B,F16B

Abstract:
1. A composite joist floor system comprising: a first support structure; a second support structure; a plurality of joists spaced apart and extending from the first support structure to the second support structure; decking supported by the plurality of joists; a plurality of stand-off fasteners adapted to be fastened through the decking to the plurality of joists, each stand-off fastener of carbon steel comprising a lower portion and an upper portion where the lower portion has a clamping part capable of clamping the decking to the joist, the lower portion having a threaded portion adjacent the clamping part with a through hardness of between HRB 70 and HRC 40 and having the lower portion of the fastener with a thread-forming portion adjacent the threaded portion of at least HRC 50 hardness adapted to enable the fastener to form threads in an upper chord of a joist, and a fluted lead portion adjacent the thread-forming portion of at least HRC 50 hardness with a nominal diameter between 80 and 98% of major diameter of the threaded portion adapted to form a fastener opening in an upper chord of a joist, the thread-forming portion having a series of lobes with recesses between said lobes structured by a failure torque to thread-forming torque of at least 3.0 and a drive torque at least 20% less than a thread-forming torque, and the upper portion of the stand-off fasteners have a through hardness of between HRB 70 and HRC 40 and when installed, at least a portion of the upper portion of each stand-off fastener extends significantly above the decking; and a cementitious slab supported by the decking and encapsulating the upper portion of each stand-off fastener extending above the decking.