Connectors advance tilt-up, precast panel site practice
- Published: Friday, 14 October 2011 18:39
- Written by CP Staff
Connect-EZ has announced the launch of two new products—Connect-EZ Panel Anchor (“PA”) and the Connect-EZ “V”. Both are said to save time and money in cast-in-place, precast and tilt-up construction projects.
“Because the Connect-EZ systems eliminate field welding, connections of the concrete panels to foundations and connections of structural steel framing to panels is safer, faster and ensures a better quality connection,” said Robert P. Foley, P.E., the company’s co-founder. “Contractors and engineers have discovered that substituting mechanical connections for difficult to inspect field welds has resulted in reduced structural inspection fees and expensive rework charges.”
The products also offer benefits related to safety and productivity, which are critical competitive factors. According to Terry Tincher, Connect-EZ co-founder, “The growing series of innovative connection devices are designed with safety and labor savings in mind. Our goals are to help our customers be more competitive and provide a safer work environment.”
In response to the ACI 318 code requiring of a pair of 10,000-lb. tension connections for tilt-up and precast concrete wall panels to the building foundation, the Connect-EZ “PA” provides an efficient, cost effective solution. This mechanical connection, usually positioned inside the building, provides contractors ready access for drilling and installation of the anchor bolt and eliminates expensive exterior patching.
Engineers have acknowledged that the product reduces exposure to corrosion and ensures that concrete anchors are installed within 6 degrees perpendicular to the connected concrete surface as required per anchor test and qualification criteria of ACI 355.2. The Connect-EZ Panel Anchor can be modified to meet specific conditions for applications in seismic zones C and higher or for overturning forces due to wind loads. Further, it may be installed using Simpson Strong-tie 3/4-in.-diameter, Titen HD screw anchors with 6.75-in. minimum nominal embedment depths in normal weight concrete, with approval of the engineer of record.
Developed in response to requests from steel erectors and concrete contractors, the Connect-EZ “V” provides a secure mechanical connection for erection of structural steel to concrete without the expense and uncertainty of field welding. The interlocking chamber and bearing seat engage remotely, eliminating the need to manually connect the steel to the concrete. The result is reduced labor and equipment cost, as well as increased job site safety during steel erection. The Connect-EZ “V” mechanical connection ensures contractors and engineers an increased confidence in the integrity of every connection. Further, third-party structural inspections are conducted quickly and reliably.
The Connect-EZ “V” chamber is cast integrally in tilt-up, precast or even cast-in-place structures in a fashion similar to the traditional embedded plate. The interlocking bearing seat is fabricated with slotted holes allowing up to 2 inches of lateral tolerance. The chamber and bearing seat engage remotely, eliminating manual connection as well as the need for a welder on scaffolding or a hydraulic lift. Productivity rates of 3.5 minutes per erected steel member are routinely achieved in the field.
The Connect-EZ “V” transfers loads from the steel frame structure to the concrete structure in a fashion similar to the traditional embedded steel plate with studs. The structural engineer’s design of the studs to transfer loads from the Connect-EZ “V” to a concrete section may be accomplished according to well-established methods available in Appendix D of ACI 318 and/or PCI Design Handbook (the sections related to design of embedded steel plates and studs).
To understand the behavior and capacity of the Connect-EZ system a series of load tests (up to 75,000 lbs. gravity load) were conducted at the University of Cincinnati in March of 2011 on 12- x 12-in. devices. The test apparatus allowed application of lateral load simultaneously with gravity, pullout, or uplift loads that were transferred from the C-EZ bearing-seat to the Connect-EZ chamber and from the Connect-EZ chamber to four ¾-in. diameter steel studs.
Although new to the marketplace, several contractors have already found great benefit from the systems. Kim Mulder, president of STAR Design-Build Contractors of Amherst, Ohio, stated that the company erects their own steel on construction projects, and using the Connect-EZ system saved them labor time during the erection process. “We saved man hours by having one person making two connections at the same time both safely and securely,” said Mulder. “Connect-EZ will be used on future projects for our company. Any time a product or method comes along to help increase productivity, while maintaining safety and extending value to the customer, it cannot be overlooked.”
Mark Meyer, president of Meyer Brothers’ Building Co. of Lee’s Summit, Mo., noted that the Connect-EZ system makes their building projects faster, safer and more competitive. “The steel erector on a recent tilt-up project reported significant labor savings during erection using Connect-EZ,” said Meyer. “And the structural steel inspector was pleased that he could conduct visual inspections safely from the ground and the connections reduced field welding. We look forward to using Connect-EZ products on future projects.” — Connect-EZ; 937/903-7836; www.theconnect-ez.com