The NIST Construction Metrology and Automation Group, in cooperation with the NIST Intelligent Systems Division, is researching robotic structural steel placement as part of a project to develop an Automated Steel Construction Testbed. The initial phase of this project centers on tracking a six degree-of-freedom robotic crane with a laser-based site measurement system to provide position feedba...

Powder-actuated (also referred to as low velocity or powder-driven) fasteners are commonly used to attach cold-formed steel framing members, usually a track, to a concrete or structural steel support. Although commonly used, their behavior is less well understood than other fasteners such as screws, bolts and welds. The AISI Cold-Formed Steel Design Manual does not explicitly address powder act...

This paper describes a review of the potential use of High Strength Incorporating Ground Granulated Blast Furnace Slag and Steel Fiber Reinforced Concrete used in construction industry to improve the structural strength and reduce steel reinforcements requirements. Blast furnace slag (GGBS) has been used as a supplementary material along with the cement. It helps in increasing the durability an...

The objective of this paper is to explore the potential impact of the use of advanced high strength steel (AHSS) to form traditional cold-formed steel structural members. In this study, shell finite element models are constructed, and geometric and material nonlinear collapse analysis performed, on simulated lipped channel cross-section cold-formed steel members roll-formed from AHSS. AHSS shee...

This paper draws together some important lessons from a compartment fire test conducted by BRE in the full-scale eight storey steel building at Cardington. The experiment is briefly described, and the main structural observations are highlighted. A numerical structural model of the fire compartment, using the nonlinear analysis program ADAPTIC, is then discussed. The numerical analysis employs ...

Steel plate shear walls (SPSWs) in buildings are known to be an effective means for resisting lateral forces. By using un-stiffened walls and allowing them to buckle, their energy absorption capacity will increase significantly due to the postbuckling capacity. The post-buckling tension field action of SPSWs can provide substantial strength, stiffness and ductility. This paper presents the Fini...

Load-bearing structures of deck railway bridges with encased filler beams have been used for short and middle spans of a maximum of 24 metres. For over a hundred years they have been designed in cases with little headroom. The first bridges were constructed with no interaction between steel beams and concrete floor slabs, the structural steel working as a bearing element and the concrete in the...

Using uniaxial tensile and hardness testing, we evaluated the variability and anisotropy of the mechanical properties of an austenitic stainless steel, UNS S17400, manufactured by an additive process, selective laser melting. Like wrought materials, the mechanical properties depend on the orientation introduced by the processing. The recommended stress-relief heat treatment increases the tensil...

Flame straightening is a common procedure used for repair work in steel components. It is based on heating a local region of the part by means of a flame torch. Due to the obstruction of the heat expansion, upsetting occurs in the work material. During cooling of the squashed zone shrinkage occurs and that is associated with tension forces which lead to the desired deformation. This process is ...