Keyway Splice Box
The heart of the Keyway Splcie System is the reinforcing bar.The unique reinforcement is manufactured through a treatment of reinforcing steel bars in order to produce high yield strength material with improved ductility, bendability and weldability.Theis unique Treatment is Thermex processing.
Thermex treatment is produced by a system involving a rapid cooling operation and a severe water quench, which takes place directly after the last finishing stand. Because the bar is quenched and tempered for a controlled period of time, a lower chemical analysis than that used to produce conventional bar is needed in order to meet the physical property requirements of the ASTM A615/A615M specification. In many cases the material meets the carbon and carbon equivalent limits of ASTM A706/A706M and is therefore a readily weldable materials.
The improved physical properties result from the short time quench and temper treatment which produce a dual metallurgical structure in the cross-section of the bar. The structure of the outer portion of the bar is tempered martensite, a strong material, while the core structure is a combination of ferrite-pearlite, a ductile material. The quenching is performed in a series of special tubes located immediately following the last rolling mill stand. The quenched outer case is tempered by the heat of the core as it migrates out of the bar on the cooling bed, prior to shearing and bundling
The bars possess higher than typical elongation numbers along with the higher yield strength. Bendability and rebendability is excellent. Breakage during fabrication is very minimal. The bars are produced and certified to ASTM A615/A615M. They meet some of the properties of A706/A706M but do not meet the seismic requirements generally and cannot be certified to that specification.