I-Corps: ULTRA HIGH PERFORMANCE CONCRETE USING A SUSTAINABLE MATERIAL

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The broader impact/commercial potential of this I-Corps project is the development of an advanced concrete material: ultra-high-performance concrete (UHPC) that is durable and able to resist chemical and environmental distress. With the use of this material, the average life span of our nation’s transportation infrastructure may be significantly extended. UHPC has potential value because it is designed with superior mechanical strength, ductility, post-cracking behavior, and longer-term durability. UHPC may be used in applications for prefabricated bridge elements, pile cap closure pores, bridge deck overlays and repairs, and as a grout for bridge shear keys. In addition, the UHPC formulation may be produced on the job site by local contractors using local materials that will meet both state departments of transportation and federal highway administration specifications. This I-Corps project is based on the development of ultra-high-performance concrete (UHPC) using local materials and industrial by-products such as coal ash, steel slag, and limestone powder. This material has been shown to exhibit superior mechanical strength and longer-term durability. UHPC’s use in the United States may be limited due to its high cost. The cost of UHPC may be reduced, and its durability and sustainability improved, by using local materials reducing cement, silica fume, steel fiber, and fine sand contents. Cement and silica fume contents may be reduced by using fly ash and ground granulated blast furnace slag (GGBS) as supplementary cementitious materials (SCMs). The use of these SCMs reduces the cost and results in eco-efficient UHPC. The laboratory results obtained so far indicate that the proposed material is comparable with currently available products in terms of compressive and tensile strengths and durability properties: resistance to rapid freeze-thaw cycles, resistance to chloride ion penetration, and resistance to sulfate attack. The rapid chloride ion permeability testing results showed that the proposed UHPC has negligible chloride ion ingress, while the material exhibited excellent resistance to rapid freeze-thaw cycles and sulfate attack.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.