Sriram Aaleti and Sri Sritharan 1 DESIGN OF UHPC WAFFLE DECK FOR ACCELERATED BRIDGE CONSTRUCTION. Sriram Aaleti 1 and Sri Sritharan 2

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1 Sriram Aaleti and Sri Sritharan 0 DESIGN OF UHPC WAFFLE DECK FOR ACCELERATED BRIDGE CONSTRUCTION Sriram Aaleti and Sri Sritharan Assistant Professor, Department of Civil, Construction and Environmental Engineering, University of Alabama, 0C, SERC Building, Tuscaloosa, AL, ; Phone: 0--0; Fax: 0--0; saaleti@eng.ua.edu (Corresponding Author) Wilson Engineering Professor, Department of Civil, Construction, and Environmental Engineering, Iowa State University, Town Engineering Building, Ames, IA, 00-; Phone: --; Fax: - -; sri@iastate.edu Submission Date: August st, 0 Words in Text: Number of Figures: Number of Tables: Total Word Count: 0 TRB 0 Annual Meeting

2 Sriram Aaleti and Sri Sritharan 0 ABSTRACT As a part of an innovation project funded by the Federal Highway Administration (FHWA) Highways for LIFE program (HfL), a full-depth precast, ultra-high-performance concrete (UHPC) waffle deck panel and appropriate connections suitable for field implementation of waffle decks were developed. Following a successful full-scale validation test on a unit consisting of two panels with three types of connections under laboratory conditions, the waffle deck was installed successfully on a replacement bridge in Wapello County, Iowa. The subsequent load testing confirmed the desirable performance of the UHPC waffle deck bridge. Using the lessons from the completed project and outcomes from a series of simple and detailed finite element analyses of waffle decks, a design guide was developed to help broaden the design and installation of the UHPC waffle deck panel cost effectively in new and existing bridges. This paper provides a summary of the waffle deck design introduced in the guide as it is applicable new bridges. To minimize cost of this new bridge deck system, information on maximum spacing of ribs and simplified connections, along with design of the deck panel for positive and negative moments are presented. TRB 0 Annual Meeting

3 Sriram Aaleti and Sri Sritharan INTRODUCTION The combination of aging infrastructure, increasing numbers of structurally deficient or obsolete bridges, and increasing traffic volume in the US demands both rapid improvements to the Nation s bridge infrastructure and increase in bridge longevity. The increased emphasis on work zone safety, user costs associated with traffic delays and environmental impacts of the construction process, requires development of technologies and structural details suitable for accelerated construction. In consideration of these challenges, the Federal Highway Administration (FHWA) has been promoting Accelerated Bridge Construction (ABC) methods using prefabricated bridge elements. In the context of ABC, precast concrete deck panels are being increasingly utilized by Departments of Transportation (DOT) in several states for both bridge deck replacements and new structures to decrease construction time (). Furthermore, the use of prefabricated full-depth precast concrete deck systems can accelerate the construction and rehabilitation of bridge decks significantly, while extending the service life and lower life-cycle costs of the bridge decks and minimize the delays and disruptions to the community (). However, transverse connections used previously between precast bridge deck panels have exhibited various serviceability challenges due to cracking and poor construction of connections (). Therefore, it is imperative that durable and efficient field connections be developed to implement precast deck panels successfully in practice. These connections can utilize high-performance materials such as ultra-highperformance concrete (UHPC) to ensure improved performance. While these materials may adhere well to the precast components, it is important to design these connections to prevent cracking and leakage along the connection interfaces between precast elements. UHPC is a newly developed concrete material that exhibits high compressive strength, dependable tensile strength, and excellent durability properties including very low permeability. The superior structural characteristics and durability of UHPC are perceived to provide major improvements over ordinary concrete and high-performance concrete (HPC) bridges in terms of long-term structural efficiency, durability, and possibly cost-effectiveness. Hence, the construction of new bridges and renewal of aging highway bridges using UHPC has been explored in terms of improving construction efficiency, enhancing bridge performance, and reducing maintenance and life-cycle costs. Previous use of UHPC for bridge applications (mostly in bridge girders) in the US has proven to be efficient and successful (,,, and ). A prefabricated UHPC waffle deck system with field-cast UHPC connections was developed as part the FHWA Highways for LIFE (HfL) program by combining the advantages of UHPC with those of precast deck systems. An integrated experimental and analytical study was performed to evaluate the performance of the precast UHPC waffle deck system and UHPC connections under laboratory () and field conditions (). The UHPC waffle deck system performed extremely well under service, ultimate and fatigue loading, with the latter two tests completed under the laboratory conditions. The ultimate capacity tests revealed that the UHPC waffle deck system had significantly higher capacity than the required design level capacity (0), suggesting potential improvements to the design of the UHPC waffle deck system and reduction in the construction costs. Given the success of the precast UHPC waffle deck system and increased interest in fulldepth precast deck panels for ABC, a design guide was developed to increase the awareness, improve efficiency, and broaden the use of UHPC waffle deck systems for new and replacement bridges. This guide provides the technical and practical information necessary to allow future bridge owners to consider the use of UHPC waffle slabs in a wide variety of bridge types. This TRB 0 Annual Meeting

4 Sriram Aaleti and Sri Sritharan paper focuses on the recommendations developed for the design of the waffle deck slab and a suitable set of connections as applicable to new bridges. ULTRA-HIGH PERFORMANCE CONCRETE UHPC is an advanced, highly engineered, cementitious material consisting of typical portland cement, fine aggregate made of sand, silica fume, crushed quartz, steel fibers, super plasticizers, and high water reducers. A few notable differences in the UHPC composition when compared to HPC are the lack of coarse aggregate, addition of steel fibers, high proportions of cementitious materials, and low water/cement ratio. The use of powder and well-graded constituents helps to achieve a high packing density for the UHPC, leading to significantly improved mechanical properties such as increased compressive strength and considerable tensile strength as compared to HPC and normal-strength concrete (NSC). The use of steel fibers in UHPC improves the material s ductility as well its tension capacity. Based on an extensive literature review of UHPC research done in the U.S., recommendations for the material behavior as applicable in the design of structures are presented in the design guide (). A selected set of recommendations, which are critical in the design of precast waffle deck system, are presented below. In precast environments, UHPC is commonly subjected to heat treatment at F at percent humidity conditions to accelerate the full development of its strength and durability properties. However, this is not a requirement. Ambient or air curing of UHPC is also appropriate depending on the constraints set forth by the specific application (e.g., field cast joints between deck panels) The compression behavior of UHPC is linear upto a strain of The design compressive strength of the UHPC can be taken as ksi and ksi for heat treated and air-cured (ambient curing) conditions, respectively. The tension behavior of UHPC can be represented with an elastic-perfectly plastic curve. The design tension strength of the UHPC can be taken as. ksi. The elastic modulus of UHPC can be approximated to. In the absence of exact concrete strength, a modulus value of,00 ksi can be used for design purposes. The unit weight of the UHPC is lb/ft. The minimum concrete cover for unprotected mild steel reinforcement in UHPC shall be 0. inches because of excellent durability properties of UHPC. UHPC WAFFLE DESK SYSTEM Analogous to the typical full-depth precast deck systems currently used in practice and developed in previous research (), the waffle deck system consists of a series of UHPC waffle deck panels that are full-depth in thickness (as required by the structural design) and connected to the supporting girders with robust connections. A UHPC waffle deck panel consists of a thin slab, cast integrally with concrete ribs spanning in the transverse and longitudinal directions. This system is similar to the two-way joist system used by the building industry. The schematic of the waffle deck system is shown in FIGURE. The transverse ribs along the deck panel acts as T-beams, distributing wheel load effects to the adjacent bridge girders. The longitudinal ribs help in distributing the wheel load to the adjacent panels through the panel-to-panel connections. TRB 0 Annual Meeting

5 Sriram Aaleti and Sri Sritharan The reinforcement needed to resist the wheel loads is provided in the ribs along both directions. The spacing of the ribs in both directions is determined based on the girder-to-girder spacing, panel dimensions, and minimum detailing requirements for panel-to-panel connections. 0 FIGURE Schematic of UHPC waffle deck system The UHPC waffle deck system for a given thickness has the same or higher capacity and is 0 to 0 percent lighter than a comparable solid precast full-depth panel made of normal strength concrete due to the improved structural properties of UHPC. The decreased weight of the UHPC panel has significant benefits including, increase in span length for a given girder size, increase in girder-to-girder spacing, improvement in bridge ratings when used for deck replacement projects, and reduction in seismic, substructure, and foundation loads when TRB 0 Annual Meeting

6 Sriram Aaleti and Sri Sritharan 0 compared to solid precast deck panel systems. The presence of the steel fibers in UHPC and very minimal shrinkage of UHPC after steam curing of the precast elements also decreases the reinforcement requirements when compared to traditional precast deck panels. DESIGN OF WAFFLE DECK PANELS The design of the waffle deck panels consist of two main steps: geometrical design and structural design. In geometrical design, critical dimensions of the waffle deck panel are arrived based primarily on the bridge functional requirements. The structural design phase consists of the design of the primary deck reinforcement (both transverse and longitudinal) to resist the AASHTO design loads. Geometrical Design: In this section, several recommendations to arrive at the dimensions of the UHPC waffle deck panel are provided Thickness of the waffle deck panel: Considering the minimum thickness requirements of Article.. of AASHTO 00 and structural capacity requirements, an -inch thick panel was found to be structurally sufficient for most cases. Length and width (dimensions perpendicular and parallel to direction of the traffic): length and width of the panel depends on the handling requirements of the panels at the precast plant and at the job site along with the transportation constraints. If the roadway width is more than ft, it is recommended to use waffle panels with lengths equal to half of the roadway width. The width of the panel will depend on the bridge geometry and thus left to a designer s judgment. However, ft to ft wide precast panels are appropriate for practical use. Thickness of slab: The thickness of the slab connecting the ribs on top in the UHPC waffle deck panel is dictated by the punching shear capacity of the plate between the ribs, cover requirements of top transverse and longitudinal reinforcement, and any anticipated surface wearing over time. Based on an experimental test completed at Iowa State University (ISU) () and the limited data available on punching shear capacity of UHPC (, ), flat plate thickness of. inches is recommended. Dimensions of the longitudinal and transverse ribs: Based on the side cover requirements for the reinforcement, as well as the previous studies completed by the FHWA () and ISU (), the width of transverse and longitudinal ribs was chosen to be inches at the bottom with a gradual increase to inches at the top of the ribs at the rib-to-plate interface (see FIGURE b). Spacing of the longitudinal and transverse ribs: The spacing between the transverse and longitudinal ribs will depend on the girder-to-girder spacing, width of the panel, and minimum number of dowels required for establishing sufficient panel-to-panel connections as the dowels are located within the longitudinal ribs. Based on the limited available data on punching shear behavior and the results from detailed D finite element analyses of waffle deck panels with different rib spacing in ABAQUS (), the maximum allowable rib spacing of inches is suggested to control the extent of flexural panel cracking under service loads and limit the extent of local damage to the flat slab at ultimate loads. Support rib spacing: The support longitudinal ribs, which are located at the girder lines (see TRB 0 Annual Meeting

7 Sriram Aaleti and Sri Sritharan 0 FIGURE b), provide an enclosure for the girder-to-panel connection, and is referred to as the shear pocket connection, making the support rib spacing dependent on the top flange width of the girder. It is recommended that the support rib spacing is limited to a value less than the beam top flange width, with a minimum value of inches (see FIGURE c). Shear Pockets: Shear pockets facilitate the connection to achieve full composite action between the precast waffle panels and supporting systems (concrete girders, steel girders, stringers, etc.). If the shear studs/hooks are positioned uniformly along the girder length (typical in concrete girder), the shear pocket spacing should be equal to the transverse rib spacing. However, if a group configuration is used for the shear studs, the shear pockets can be placed at spacing of to ft apart, in agreement with the maximum shear stud group spacing allowed by the AASHTO guidelines () and the recent studies on shear stud group spacing (). FIGURE Recommended geometric dimensions for waffle deck panels Flexural Design: The experimental testing of waffle deck system at Iowa State University demonstrated that the wheel load is distributed to the supporting girders in a similar fashion to the traditional TRB 0 Annual Meeting

8 Sriram Aaleti and Sri Sritharan 0 0 cast-in-place deck system (). The extent of distribution of the wheel load among the transverse ribs of the waffle panel is dependent on the rib spacing and girder spacing. Therefore, the waffle deck panel system can be designed conservatively using the strip method as described by the current AASHTO LRFD specifications (). The transverse strip, whose width is estimated according to the Article... in the AASHTO specifications (), is analyzed as a continuous beam supported by bridge girders, which are assumed to be considered as nonsettling rigid supports. The transverse strip width depends on the location of the critical section along the length of the panel for in the +ve moment (+M), -ve moment (-M) or overhang regions. The transverse strip width for the waffle deck system can be arrived using AASHTO specifications and is given by Eq.();. The entire transverse strip is designed to resist the dead load and live load effects with appropriate load factors at different limit states. +. S (ft) for +ve moment transverse strip width W ts (in.) +.0 S (ft) for -ve moment () +0.0 X (ft) overhang where S = girder-to-girder spacing in feet and X = distance of the critical location from the centerline of exterior girder (in feet). Design Loads The design loads include the dead load due to self-weight of waffle panel and wearing surface (if used), live load (design truck load) and collision loads. Design moments are determined at three different regions along the panel cross-section including, section at the center of span between the girders, sections over interior girders, and the overhang section. As detailed in the AASHTO guidelines, the interior spans between girders are investigated for positive bending at the strength-i limit state. Sections over interior girders are examined for negative bending at the strength-i limit, while the overhang region is investigated for different combinations of dead, live, and collision loads for the strength-i and extreme event II limit states. The deck system should be also designed to satisfy the serviceability requirements as required by the AASHTO... article. The previously established geometric details along with the following design parameters are used while arriving at the loads on the deck panels. 0 The longitudinal and transverse rib spacing vary between to inches. A girder centerline spacing of to 0 ft, which was established based on an extensive review of frequently used standard details used by several State DOTs including Alabama, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Nebraska, New Jersey, New York, Ohio, Oklahoma, Virginia, and Wisconsin. Dead Load Dead load on the waffle panel includes the self-weight of the panel (DC) and the weight of any future wearing surface or overlays (w ws ) (if used by the DOT). The self-weight of the waffle deck panel will depend on the rib spacing and is given by Eq.(). TRB 0 Annual Meeting

9 Sriram Aaleti and Sri Sritharan S tr bwh w uhpc wwaffle (in psf.) hslab () Slr S tr where h slab = thickness of top slab in inches (=. in.), S tr = transverse rib spacing in inches, S lr = longitudinal rib spacing in inches, h w = rib height in inches (= h deck h slab ) (= in. -. in. =. in.), and uhpc = unit density of UHPC (= pcf ). The design dead load is given by following equation. w =. w W. w W () dead u waffle ts ws Live Load The precast deck panel is designed for HL- truck loading. More details of the HL- truck loading can be found in Section. of the AASHTO LRFD Bridge Design Specifications (). Design moment The moment demand for deck panel between the girders (+ve moment region) and at the interior girder locations (-ve moment region) is estimated using the strength-i limit state. The positive and negative moment demand due to the dead load can be estimated using Eq.(). dead DL DL wu S M u= M u =, where S = girder spacing. () 0 LL LL The positive and negative design moments due to the live load ( Mu and M u ) can be arrived at using the AASHTO LRFD Bridge Design Specifications Table A-. The maximum +ve and ve moment demand varies from. kip-ft/ft to. kip-ft/ft and. kip-ft/ft to. kip-ft/ft respectively, with the girder spacing changing from ft to 0 ft. Design moment values for different girder spacing can be found in Aaleti et al. (). Flexural Capacity Calculation Moment capacity of the waffle deck panel in the positive and negative bending directions can be estimated using a transverse strip along the deck panel (see FIGURE a). As shown in FIGURE b, the equivalent strip width contains a number of ribs depending on the girder span and rib spacing in the waffle deck panel. The cross-section of the transverse strip can be further divided into a combination of T-beams with a cross-section, as shown in FIGURE c. The flange width for positive bending (b +ve f ) or negative bending (b -ve f ) can be estimated using the Eq.(). +ve -ve +ve Wts -ve Wts b f = and b +ve f () -ve Wts Wts +interger value of +interger value of S tr S tr where W +ve ts and W -ve ts = equivalent strip width for positive moment and negative moment regions, respectively. ts TRB 0 Annual Meeting

10 Sriram Aaleti and Sri Sritharan 0 The moment capacity for the T-beam cross-section can be estimated using the strain compatibility approach as shown schematically in FIGURE. FIGURE Cross-section of an equivalent strip for positive and negative bending TRB 0 Annual Meeting

11 Sriram Aaleti and Sri Sritharan 0 FIGURE Strain and stress profiles for estimating the positive nominal moment capacity of a T- shaped UHPC beam Deck Reinforcement From the observations from the experimental testing of waffle deck panel and a detailed D finite element model, two configurations for deck reinforcement in transverse ribs using # and # bars are proposed. The nominal positive and negative bending moment capacities of waffle deck panels for different girder spacing and transverse rib spacing configurations can be estimated using the strain compatibility approach as illustrated in FIGURE. The cross-section configurations are shown in FIGURE and denoted by UWDTB and UWDTB. The estimated nominal moment capacities of the two cross-sections different girder and transverse rib spacing are presented in Table and Table, which simplifies the design process. FIGURE The reinforcement details recommended for transverse ribs TRB 0 Annual Meeting

12 Sriram Aaleti and Sri Sritharan TABLE Nominal moment capacities of UWPTB in kip-ft/ft. TABLE Nominal moment capacities of UWPTB in kip-ft/ft. TRB 0 Annual Meeting

13 Sriram Aaleti and Sri Sritharan 0 0 Overhang Design The overhang region is designed for different combinations of dead, live, and collision loads for the Strength I and Extreme Event II limit states as required by AASHTO guidelines (). An F-shape standard concrete railing is used for designing the overhang region for collision loads. In addition, based on the suggestions from Iowa DOT designers, it is recommended to use a solid cross-section for the overhang region instead of a waffle configuration. The solid section for the overhang will not only help in addressing the variability in the types of railings and their capacities as used by DOTs, but also provide adequate space to include the necessary details for attaching the railing to the precast deck. The negative moment capacity of the solid overhang for the UWPBT and UWPTB configurations was found to vary between. kip-ft/ft to. kip-ft/ft depending on the transverse rib spacing. Connection Details The short-term and long-term performance and durability of bridges constructed using these deck panels will be influenced by the quality of the connections among the panels (i.e., panel-to-panel connections in both longitudinal and transverse directions) and with panels to girders. Panel-to-panel connections are subjected to bending moments and vertical shear forces under vehicular loading. In recent decades, a wide variety of deck level connection designs have been deployed in bridge projects involving full-depth precast panels with substantial variance in observed performance under traffic loads. Several of these connection details are provided in the design guide (). The connections that perform well typically consist of match-cast shear keys with epoxy adhesive or grouted female-to-female joints with discrete reinforcement, combined with field-cast concrete or grouted together with quality construction. A few connection details that are appropriate for the waffle deck panel-to-panel connection are shown in FIGURE. By realizing the superior durability and bond characteristics of UHPC, all the connection regions are designed with field casting of UHPC. The connection details presented in Figures b, c and d were developed for solid deck panels. However, these connections can be adopted for waffle deck panels by making the cells adjacent to the connections to be solid. TRB 0 Annual Meeting

14 Sriram Aaleti and Sri Sritharan 0 FIGURE Recommended panel-to-panel connection details (, ) The deck panels are made to act compositely with the girders by connecting them together using recommended connection details shown in FIGURE. These connections were developed as part of the HfL program and their performance was extensively tested under service, ultimate and fatigue loads (, ). FIGURE a shows a longitudinal panel-to-panel-togirder connection detail using dowel bars extending from the panels and shear hooks protruding from the girder, which are tied together with additional reinforcement placed longitudinally (along the girder length). The void between the panels is subsequently filled with UHPC. The deck panels are also supported between the edges by bridge girders. To provide a connection between the panel and girder, shear pockets are provided at intervals along the deck panel and clusters of horizontal shear connectors are left protruding from the supporting girder at these locations. In this connection, shown in FIGURE b, shear hooks extending from the girder are embedded into UHPC that is poured to fill the shear pocket. When connecting to steel girders. Shear studs instead of shear hooks may be used as per the AASHTO guidelines. FIGURE c and FIGURE d shows the details used in the Wapello County Bridge in Iowa, which was built using the UHPC waffle deck panels. TRB 0 Annual Meeting

15 Sriram Aaleti and Sri Sritharan FIGURE Recommended panel-to-girder connection details 0 CONCLUSIONS Following a successful laboratory validation followed by field implementation and evaluation of UHPC precast waffle deck system in Iowa, a design guide to broaden the applications of UHPC waffle deck panels to new bridges as well as deck replacement projects was developed. To minimize cost of this new bridge deck system, information on maximum spacing of ribs and simplified connections are presented along with design of the deck for positive and negative moments. The conclusions from this design study are presented below. For broader applications, -in. thick UHPC waffle panel deck is recommended. This waffle TRB 0 Annual Meeting

16 Sriram Aaleti and Sri Sritharan 0 deck is to have the ribs in both directions with recommended rib spacing of to inches. Two different configurations for transverse rib reinforcement, which are applicable for different girder spacing, are proposed (see FIGURE ). The first configuration (UWDTB) consists of # bars at the top and bottom of the transverse rib. The alternate configuration (UWDTB) consists of a # bar at the bottom and a # bar at the top of the transverse rib. In both configurations, # bars are provided in the longitudinal ribs at top and bottom. The UWDTB configuration can be used for waffle deck panels with any rib configuration (rib spacing < inches) in bridges with a maximum girder spacing of. ft. This configuration can be used for bridges with a girder spacing of. to 0 ft if the transverse rib spacing is limited to inches. The UWDTB configuration can be used for waffle deck panels with variable transverse and longitudinal rib spacing in bridges with a maximum girder spacing of. ft. For girder spacing of. to 0 ft, the transverse rib spacing is limited to 0 inches. To establish robust connection between waffle deck panels and girders, three different connections including their details are presented. Their adequate performance under variety of loads has been already verified ACKNOWLEDGEMENTS The authors would like to thank the Federal Highway Administration (FHWA) Highways for LIFE (HfL) program. Special thanks are given to Julie Zirlin, HfL Technology Partnerships coordinator, for her advice and suggestions, and Ahmad Abu-Hawash, chief structural engineer with the Iowa DOT Office of Bridges and Structures for his coordination and valuable input. In addition, valuable feedback was received during the design guide development process from a number of people, including Benjamin Graybeal with the FHWA Turner-Fairbank Highway Research Center, Dean Bierwagen, Kenneth Dunker, Ping Lu, and Michael Nop with the Iowa DOT, Mathew Royce with the New York State DOT, Bruce Johnson with the Oregon DOT, Claude Napier with the Virginia DOT, and Brian Moore with Wapello County, Iowa. REFERENCES. Issa, M. A., Yousif, A. A., and Issa, M. A. Experimental Behavior of Full-Depth Precast Concrete Panels for Bridge Rehabilitation. ACI Structural Journal. V., No., May- June 000. pp Berger, R. H. Full-Depth Modular Precast Prestressed Bridge Decks. Bridges and Culverts. Transportation Research Record: Journal of the Transportation Research Board. No. 0. Transportation Research Board of the National Academies. Washington, DC.. pp. -.. Issa, M. A., Cyro do V., Abdalla, H., Islam, M. S., and Issa, M. A. Performance of Transverse Joint Grout Materials in Full-Depth Precast Concrete Bridge Deck Systems, Precast/Prestressed Concrete Institute (PCI) Journal. V., no., July-August 00. pp Bierwagen, D., and Abu-Hawash, A. Ultra-High Performance Concrete Highway Bridge. Proceedings of the 00 Mid-Continent Transportation Research Symposium, Ames, Iowa. 00. pp.-. TRB 0 Annual Meeting

17 Sriram Aaleti and Sri Sritharan Keierleber, B., Bierwagen, D., Wipf, T., and Abu-Hawash, A. Design of Buchanan County, Iowa Bridge Using Ultra-High Performance Concrete and Pi-Girder Cross Section. Proceedings of the Precast/Prestressed Concrete Institute National Bridge Conference, Orlando, FL Wipf, T. J., Phares, B. M., Sritharan, S., Degen, E. B., and Giesmann, T. M. Design and Evaluation of a Single-Span Bridge Using Ultra-High Performance Concrete. IHRB Project TR-. Iowa State University, Ames, IA. September 00.. Rouse, J. M., Wipf, T. J., Phares, B., Fanous, F., and Berg, O Design, Construction, and Field Testing of an Ultra High Performance Concrete Pi-Girder Bridge. IHRB Project TR-. Iowa State University, Ames, IA. January 0.. Aaleti, S., Sritharan, S., Bierwagen, D., and Wipf, T., J. (0 a) Structural Behavior of Waffle Bridge Deck Panels and Connections of Precast Ultra-High-Performance Concrete: Experimental Evaluation. Transportation Research Record: Journal of the Transportation Research Board. No.. Transportation Research Board of the National Academies, Washington, DC. 0. pp. -.. Aaleti, S., Sritharan, S., Bierwagen, D., and Moore, P., B.(0 b) Precast UHPC Waffle Deck Panels And Connections For Accelerated Bridge Construction 0 PCI National Bridge Conference, Salt Lake City, Utah, October -, 0 0. Rouse, M., Honarvar, E., Aaleti, S., Sritharan, S., and Wipf, T. Phase : The Structural Characterization of UHPC Waffle Bridge Deck Panels and Connections. IHRB Project TR- Report. Iowa State University, Ames, IA. 0.. Aaleti, S., Peterson, B., and Sritharan, S., (0). Design Guide for Precast UHPC Waffle Deck Panel System, including Connections, Report No. FHWA-HIF--0, Federal Highway Administration, Washington, DC., June 0. Badie, S. S., and M. K. Tadros. 00. Full-Depth Precast Concrete Bridge Deck Panel Systems. NCHRP Report. National Cooperative Highway Research Program. Transportation Research Board of the National Academies. Washington, DC Harris, D. K., and C. L. Roberts-Wollmann. 00. Characterization of The Punching Shear Capacity Of Thin Ultra-High Performance Concrete Slabs. VTRC 0-CR final report, Virginia Department of Transportation Graybeal, B. Analysis of an Ultra-High Performance Concrete Two-Way Ribbed Bridge Deck Slab. TECHBRIEF, FHWA-HRT-0-0. Federal Highway Administration. McLean, VA ABAQUS user's manual version., Dassault Systèmes Simulia Corp., 0. American Association of State Highway and Transportation Officials (AASHTO). AASHTO LRFD Bridge Design Specifications, th edition, Washington, DC Badie, S. S., Morgan Girgis, A., Tadros, M., and Nguyen, N. Relaxing the Stud Spacing Limit for Full-Depth Precast Concrete Deck Panels Supported on Steel Girders (Phase I). Journal of Bridge Engineering pp. -.. Graybeal, B. Behavior of Field-Cast Ultra-High Performance Concrete Bridge Deck Connections under Cyclic and Static Structural Loading. FHWA-HRT--0, Office of Infrastructure Research & Development, Federal Highway Administration. McLean, VA. 0 TRB 0 Annual Meeting