ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/622975
FOCUS CONCRETE INNOVATION IN HAWAII KSF’s focus on creating innovative designs has led to several breakthroughs in concrete materials and construction that have been incorporated into many of the firm’s projects by Craig A. KSF Inc. faces a variety of challenges designing infrastructure projects in Hawaii. Not only must it deal with the full range of seismic zones (and volcanoes) along the chain of islands, but many materials are either limited in supply or available only via overseas shipments. To offset these obstacles, KSF has devised innovative concrete mixture proportions that are becoming standard issue for its projects. “Most of the projects we create are concrete structures,” says Eric Matsumoto, vice president with the Honolulu-based firm. “Hawaii DOT [department of transportation] prefers concrete due to maintenance concerns in the corrosive environment. As a result, we have spent considerable time developing new concrete mixtures and techniques to help us handle the challenges.” Key insights come from Kirk Hashimoto, construction engineer, who previously worked in the concrete industry in engineering, marketing, and concrete mixture development. “He has helped to ensure we are creating the best concrete mixture for a project’s needs,” Matsumoto explains. “He is involved with the material usage from selection through placement and final finish.” KSF’s success has derived in part from developing in-house expertise, Hashimoto notes. “The company’s goal has been to provide core competencies in-house so we can take care of every aspect of a project. We are always looking to improve the materials we are using, and since most of our projects are concrete, that has been a point of focus.” The company also has an employee with past experience as a contractor to ensure every design maximizes constructability and efficiency. “He can give us insights into how the project will be constructed to help us create the most efficient and economical product,” explains Matsumoto. In part, that in-house expertise was dictated by the island’s isolation, Hashimoto says. “Labor costs are high on the island, and specific skills are not always accessible. We have to be aware of the limitations and work around them. We developed a lot of in-house expertise to avoid having to fly in people to consult on projects.” Materials also are in limited supply. Hawaii basically has one cement supplier, who ships from Asia, and there are no fly ash or other supplementary cementitious materials locally available that meet ASTM requirements consistently. “Those materials are more expensive than cement,” Hashimoto says. “Costs generally are higher here.” Innovative Materials Those obstacles are in part the genesis for some of the company’s innovation in concrete. Two innovations that were recently developed in a research program, which was performed in tandem with the Hawaii Department of Transportation (HDOT), were put to use on one recent project and now are used more often. The first innovation developed structural concrete for use in drilled shafts with special characteristics for workability, nonsegregation,