Robust Methods for UHPC Early-Strength Determination and Quality Control for ABC [ABC-UTC-2016-C4-UNR01]: Given the nature of ABC, many projects considering UHPC for connections and early bridge opening for traffic or following construction phases are hinging on reaching a desired early age strength. While robust mixes can accomplish this requirement, a reliable quality control method to verify such requirement on-site is still lacking. In remote sites, it becomes harder to verify the UHPC early age strength using the current state-of-practice. To help address this issue, this project will extend two methods that have been well-established and used for conventional concrete strength characterization to use for UHPC. These are using cubes as opposed to cylinders for compression tests and utilizing previously-developed strength maturity curves for quality control.
Towards Autonomous Drone-Based Dynamic and Seismic Response Monitoring of Bridges [ABC-UTC-2016-C4-UNR02]: There has been increasing interest and use of unmanned aerial vehicles (UAVs) for infrastructure inspection. The goal of this study is to extend the use of UAVs to a new application in the area of infrastructures rapid assessment under service conditions and extreme events. The project focuses on earthquakes while using unique testbeds in the Earthquake Engineering Laboratory at the University of Nevada, Reno where UAVs will be used to monitor online shake table tests.
Risk and Resilience of Bridges: Toward Development of Hazard-Based Assessment Framework, Research Needs, and Benefits of Accelerated Construction[ABC-UTC-2016-C4-FIU-OU-UNR-Collab1]: This project seeks to document and synthesize the current state of practice related to assessment of risk and resilience of bridges and other structures and conducting target surveys to identify the current state of practice with transportation agencies and cities. The collected information will be utilized to develop holistic resilience and risk assessment framework for existing and new bridges, including ABC bridges, accelerated upgrade (enhanced robustness), and accelerated repair (enhanced rapidity), under multi-hazards to emphasis on accelerated construction benefits.
Application of Methacrylate Polymers for Seismic ABC Connections [ABC-UTC-2016-C3-UNR03]: Previous research has demonstrated the validity and effectiveness of grouted ducts filled with proprietary and non-proprietary UHPC for seismic ABC column-to-footing and column-to-cap beam connections. However, there is a need for more alternatives in case of temporary market changes such as domestic steel fibers availability as related to UHPC. Polymer-based materials can provide a good candidate for this application. This project will explore polymer-based alternatives for grouted ducts connections and provide large-scale validation testing.
Innovative Foundation Alternative for High Speed Rail Application [ABC-UTC-2016-C1-UNR01]: The objectives of this project include; development and validation of innovative foundation systems for HSR applications, detailed finite element modeling; and NL FE analysis to investigate the seismic response of HSR bridges with innovative foundations. This is a joint project between FIU and UNR, with FIU focusing on the component modeling and UNR on incorporation into the bridge system.
More Choices for Connecting Prefabricated Bridge Deck Elements [ABC-UTC-2016-C1-UNR03]: The objectives of this study are to collect and select potential alternative materials (e.g. polymer concrete) to replace UHPC in PBES connections; characterize the material and mechanical properties of selected alternatives; and conduct large-scale testing to study the response of the alternative materials as used in structural ABC applications.
3rd-Cycle Projects (2013-grant)
Durable UHPC Columns with High-Strength Steel [ABC-UTC-2013-C3-UNR01]: This study aims at providing the basic knowledge needed to optimize the design of full prefabricated bridge columns using UHPC and high-strength steel under combined axial and lateral loading. Large-scale tests will be conducted to verify the seismic performance of the novel UHPC columns.
Shake Table Studies of a Bridge System with ABC Connections [ABC-UTC-2013-C2-UNR01]: ABC connections for prefabricated members are particularly critical in moderate and high seismic zones because earthquake forces place high demand on inelastic deformation of adjoining columns. Structural integrity of the bridge has to be maintained by capacity-protected connections that experience little or no damage. The overall objective of the proposed study is to investigate the seismic performance of a large-scale bridge system that integrates some of the more promising ABC connections that have been proof tested as individual components.
1st-Cycle Projects (2013-grant)
Evaluation of Seismic Performance of Bridge Columns with Couplers and Development of Design Guidelines [ABC-UTC-2013-C1-UNR01]: The overall objective of this study was to compile and interpret data on seismic performance of different types of couplers and establish characteristic column plastic hinge behavior for different coupler types. The study further categorized the couplers with respect to their seismic performance. The results of the study were transformed into draft design guidelines for possible adoption by AASHTO.
Behavior and Design of Precast Bridge Cap Beams with Pocket Connections [ABC-UTC-2013-C1-UNR02]: The main objective of this study was to compile and interpret data on seismic performance of cap beams with pocket connections and identify behavior, design, detailing, and construction considerations for successful implementation of this category of connections. The results of the study were transformed into design guidelines for possible adoption by AASHTO.
Development and Seismic Evaluation of Pier Systems with Pocket Connections and UHPC Columns [ABC-UTC-2013-C1-UNR03]: The overall objective of this study was to develop and evaluate resilient bridge piers consisting of prefabricated columns and cap beams subjected to simulated earthquake loading on shake tables. The post-earthquake damage is minimized by using prestressing CFRP tendons to control residual displacements and plastic hinge damage by using ECC and UHPC.