CompositesWorld

DEC 2018

CompositesWorld

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DECEMBER 2018 8 CompositesWorld PERSPECTIVES & PROVOCATIONS » It's December and winter is nigh in the Northern hemisphere. For many of us, it brings cold, snow and ice for the next several months. On the plus side, it means that another road construction season has passed, and with it, the disappearance of the ubiqui- tous orange barrels, detours and delays that accompany it. Come spring, they will be back, as there will inevitably be more failed bridges and roads to be replaced. •e reason for this? Cracked concrete, typically caused by rusting of the steel reinforcing rods, or rebar, used internally to strengthen the concrete. Over time and use, reinforced concrete develops small cracks, which allow water to penetrate. As water oxidizes the steel rebar, it expands up to four times its original dimen- sion, putting internal pressure on the concrete, exacerbating the cracks and allowing more water to penetrate. •e concrete eventually breaks apart, a process called spalling, prompting eventual repair or replacement. Spalling is accelerated in chloride-rich environments, such as those where deicing salts are applied, and in coastal areas subject to seawater and salt air. As a CW reader, you probably know the solution to this problem: Replace the steel rebar with one made of compos- ites! Not only does composite rebar not corrode, it is †‡% lighter and twice as strong as steel, plus it is electrically and thermally nonconductive. •is solution seems obvious and easy, but change comes slowly to the infrastructure market. Composite rebar is more expensive than bare steel, yet compares well to epoxy-coated steel, and is cheaper than galvanized or stainless steel. •e German philosopher Georg Hegel once said, "Nothing great in the world has ever been accomplished without passion." To that, I would add two other attributes necessary to e'ect change in conservative markets — persistence and patience. One person that exempli"es these three attributes is John Busel, vice president, Composites Growth Initiative of the American Composites Manu- facturers Association (ACMA). Because of the e'orts of John, and many others, we are on the precipice of widespread adoption of "ber-reinforced polymer (FRP) rebar in infrastructure construction. I sat down with Busel to better understand this journey, and what a long journey it has been! We in the composites industry typically see concrete as a material to replace; Busel sees it as an oppor- tunity to enhance. In œžžœ, the American Concrete Institute (ACI) created ACI Committee ŸŸ¡, recognizing the emerging applications of composites in internal reinforcement with rebar and pre-stressed tendons and external reinforcement with column strengthening and seismic upgrade. In œžž¢, the committee developed a "state of the art" document regarding FRP use in concrete applications. By the late œžž¡s, commercial FRP rebar products were intro- duced in "eld demonstrations. ACI issued a design guideline on composite rebar in its Emerging Technology Series in £¡¡œ, indicating this was a technology to follow. Busel chaired Committee ŸŸ¡ from £¡¡Ÿ to £¡œ¡, issuing seven standards in that time. ACI is very data- driven, and those early demonstrations provided "eld veri"cation of the durability of composites, leading to removal of the "emerging" tag from the guideline in £¡¡¢. ACI issued the current ACI ŸŸ¡.œR standard covering FRP rebar in £¡œ‡, and in £¡œ†, ASTM issued a speci"cation, ASTM †ž‡†, covering testing standards and certi"cation of FRP rebar. Committee ŸŸ¡ is currently authoring a dependent code to ACI ¤œ¥, which covers all concrete structures, to incorporate the use of FRP rebar. While these documents are signi"cant, what will truly drive market growth will be government buyers of roads and bridges demanding longer-life structures. Busel says many new projects in Canada today specify FRP rebar construction in bridges, and he expects this also will happen in the US and elsewhere, creating huge opportunities for composite rebar manufacturers. Busel gives signi"cant credit for the acceptance of FRP rebar to the leadership and vision of Antonio Nanni, professor and chair of the College of Engineering at the University of Miami. Nanni has studied composite rebar for years and has provided data to ACI that proves the material's long-term durability. Nanni also leads an e'ort to develop concrete mixtures using seawater instead of fresh water, initiating the SEACON project with US and Italian partners to demonstrate the technology at scale. FRP rebar is a key to success, as seawater contains - times the chloride content of fresh water. •e implications for island nations and arid coasts where fresh water is in short supply are signi"cant, to say the least. Composites o'er many advantages for improving infrastructure applications. If we continue to play the long game, we will prevail. Passion, persistence and patience — winning the long game We are on the precipice of widespread adoption of FRP rebar in infrastructure construction. Dale Brosius is the chief commercialization ocer for the Institute for Advanced Composites Manufacturing Innovation (IACMI), a DOE-sponsored public-private partnership targeting high-volume applications of composites in energy-related industries including vehicles and wind. He is also head of his own consulting company, which serves clients in the global composites industry. His career has included positions at US-based firms Dow Chemical Co. (Midland, MI), Fiberite (Tempe, AZ) and successor Cytec Industries Inc. (Woodland Park, NJ), and Bankstown Airport, NSW, Australia-based Quickstep Holdings. He served as chair of the Society of Plastics Engineers Composites and Thermoset Divisions. Brosius has a BS in chemical engineering from Texas A&M University and an MBA.

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