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/335723
PERSPECTIVE A Vision for Structural Concrete Research By Benjamin A. Graybeal, Federal Highway Administration From the advent of portland cement concrete in the early 1800s, to the construction of the first reinforced concrete bridges in the United States in the late 1800s, to today’s widespread use of concrete throughout the physical infrastructure, the technology of concrete has been continually advancing. These two centuries of progress have brought about structure types, construction methods, and material properties that could scarcely have been imagined when Aspdin, Vicat, and others were rediscovering the long-forgotten Roman secrets of castable stone. These advancements have largely resulted from systematic investigations that build on past knowledge to expand future applications. Research, whether geared toward addressing an immediate challenge or grasping a potential opportunity, has been the key methodology employed in the steady advancement of concrete technology. Looking back over the past few decades reveals many game-changing advancements that have enabled our sector’s current successes. Prestressing allows for dramatic increases in structural efficiency by shifting the stress state in the concrete toward its strength in compression. Admixtures, most notably high-range water reducers, allow for modification and enhancement of fresh and hardened properties, thus enabling the tailoring of concrete to specific applications. Reinforcements with enhanced strength and durability properties have allowed for the construction of robust, efficient structures. These sorts of advancements emanate from perceptive recognition of challenges and opportunities. Challenges Today, the challenges faced by our infrastructure demand innovative solutions and continual advancement. The clearest path to success is through systematic research that address today’s pressing needs while also striving toward transformational innovations that can continue structural concrete’s role as the cornerstone of our structural systems. The concrete bridge community needs to balance its research priorities to ensure that near-term challenges are addressed while also striving for broad-based advancements in our foundational technology. All too often in recent years, research funding organizations have been unwilling or unable to leverage their funds to create a strategic vision for the future of structural concrete. Instead, research dollars have been disproportionately directed toward bandage solutions that, at best, provide short-term relief to an applied engineering concern. These types of research are necessary, but through collaboration, coordination, and a willingness to strategically engage promising solutions, our researchers can also deliver the transformative innovations that will change the way concrete is used in the future. This method of strategically directing applied engineering research toward pressing challenges is not new. One recent example is the push toward accelerated bridge construction. Accelerated bridge construction stems from the need to reconstruct degraded infrastructure with minimal impact to users. The build-out of our roadway infrastructure was primarily greenfield construction, while the current reconstruction phase is space- and time-constrained in ways that can preclude traditional construction techniques. Dozens of innovative solutions have been developed to address this situation, many revolving around prefabrication and heavy-lift technologies that allow for increasingly larger portions of the infrastructure to be constructed off-site and outside the critical path. Collaboratively, the bridge community has funded and executed the needed research. The systemic challenges facing the use of concrete in infrastructure (continued next page)