High strength steel reinforcing, i.e., 90ksi and 100ksi, is gaining use in contrast to previous years when this reinforcing was cost prohibitive.
It appears that competition between the very few manufacturers of this kind of reinforcing lowered the price, making it more usable from an economical stance.
The professionals at Construction Advisory Group note that it is important to realize that while this rebar is more expensive than the conventional one, it drastically reduces the reinforcing congestion by reducing the amount of horizontal bars in columns and shearwalls -- thus generating substantial labor savings.
The reduction of horizontal reinforcing when 100ksi is used is 40% and 30% compared to when using 90ksi.
This certainly translates into less field labor, less material that is lighter in weight, less hoisting, fewer problems threading mechanical and electrical conduits and sleeves through rebar and easier concrete casting.
The use of 90ksi and 100ksi steel will be eased by the American Concrete Institute’s Design Guide for the Use of ASTM A1035 Grade 100 Steel Bars for Structural Concrete, on course for publication early next year.
This is considerable progress that deserves undivided attention.
Construction Advisory Group strongly recommends that all preconstruction efforts and cost evaluations, prior to job bid, should take into consideration this factor. Owners, general contractors, concrete contractors will all benefit, should the structural engineer of record be in agreement.