SAN DIEGO - The California Department of Transportation has given an encouraging word to advocates seeking to qualify polymer composites for seismic-retrofitting of concrete bridge columns. ``We're in the early stages of developing a system'' and by late December, may ``adopt generic specifications'' that any material must meet, said Jim Roberts, engineering service center director and structures division chief for Caltrans.
Roberts spoke at a Nov. 8 panel discussion at the Suppliers of Advanced Composite Materials Association fall conference in San Diego.
The specifications will outline performance requirements for materials that would be used in column work.
Among the competing systems are those by a University of California, San Diego-administered consortium, including XXsys Technologies Inc., that applies carbon tows and epoxy resin with a continuous-jacketing machine, and joint venture Hexcel-Fyfe Co. of Del Mar, Calif., which ``wallpapers'' columns with layers of unidirectional woven E-glass fabric and epoxy matrix.
Material suppliers need sim-plicity to convince civil engineers to use polymer composites in infrastructure applications, suggested Gilbert Hegemier, UCSD professor of applied mechanics and structural engineering and director of UCSD's Powell Structural Research Laboratories.
``Make it simple as a starting point, and build on it. The lack of national standards on materials, test procedures and design guidelines will hold everything up,'' he said.
Hegemier suggested that suppliers offer two or three classes for carbon fiber and not the numerous company specifications that exist today. He envisions civil engineers using standards between those of the sporting goods and aerospace industries.
Fred Isley, market manager at Hexcel Corp. in Pleasanton, Calif., said SACMA members are selling the composites concept with user-friendly design and durability data to civil engineers.
Philip Richter, senior technical director with Fluor Daniel subsidiary of Fluor Corp. in Irvine, Calif., said his firm must see a return in a short time to get involved in using polymer composites on construction projects.
Richter said civil engineers ``want gradual failure'' in materials and that an improvement would be a ``material with more energy before it broke.''
Joseph Perkowski, advanced civil systems program manager with Bechtel Corp. in San Francisco, said construction companies need to try as many teaming arrangements as possible, particularly with smaller firms that dominate the field, but need training.