The Charles Pankow Foundation is about to begin a nearly $27- million fund-raising campaign to support unprecedented research in high-strength reinforcing steel. The goal of the five-year research program is to simplify and speed reinforced-concrete construction by easing rebar congestion. The program would provide the scientific basis for the first major overhaul of the concrete building standard in 50 years.

"This project has the potential to change engineering practice in a significant way," says Jon A. Heintz, director of projects for the Applied Technology Council, which is managing the research project, called ATC 115: Road Map for the Use of High-Strength Reinforcement in Reinforced Concrete Design, under a $191,530 grant from the Pankow foundation. Pankow released the 95%-complete draft of the ATC 115 report on Oct. 27.

"High-strength reinforcing steel also provides the opportunity to improve construction efficiencies," thanks in large part to reduced material needs, rebar congestion, labor and cycle time per floor, says Heintz. "The long-term benefits come on the construction side, where all the big dollars are spent."

The road map includes a detailed list of the steps necessary to update the American Concrete Institute's ACI 318-14: Building Code Requirements for Structural Concrete and Commentary to allow the general use of rebar—in walls, columns, beams and slabs—with a yield strength of up to 100 ksi, even for special seismic zones.

Nearly every chapter of ACI 318 will be affected by the research, says Dominic J. Kelly, a structural-engineer partner with Simpson Gumpertz & Heger and ATC 115's project technical director.

There hasn't been targeted research to support a code change since the late 1960s, when the standard minimum yield strength for rebar jumped to 60 ksi from 40 ksi, or Grade 40. Most of the U.S. code is based on research on lower-strength concrete. Currently, engineers more routinely specify higher strengths, from 8,000 psi to 14,000 psi and greater.

Grade 80 rebar has been in the code for gravity systems since 1971. However, engineers in highly seismic zones, such as the West Coast, are limited by the code to the use of 60 ksi.

研究目标

到明年年底，目标是完成研究以修改ASTM A615规范，以在2016年ACI 318的2016年临时规定中及时包括100级钢筋。该报告说，要使材料生产商完善其冶金和制造工艺，以更好地满足与与开发100级增强型地震和其他应用相关的工程需求相关的工程需求相关的需求。

最终目标是更改ACI 318代码，以允许在所有系统中使用100 KSI，这可能需要数年。目标是代码的2022版本。

在Pankow董事会任职的结构工程师Magnusson Klemencic Associates董事长兼首席执行官Ron Klemencic说：“我对该计划感到兴奋，但也对更改代码需要多长时间感到沮丧。”

39项研究项目概述了钢筋生产和规新利18备用网址格，成员强度，可维护性，增强限制，细节，一般考虑分析和抗震。该报告可免费提供www.pankowfoundation.org/atc115。