2013 Session: 628

• Assessment of Shear Capacity of Existing Reinforced-Concrete Solid Slab Bridges
  Abstract: Several existing reinforced concrete solid slab bridges in the Netherlands do not meet the criteria for shear when calculated according to the recently implemented Eurocodes. The shear capacity is assessed by comparing the design beam shear resistance to the design value of the applied shear force due to the dead load, permanent load and live load. Transverse load redistribution which occurs in slabs is not taken into account.To evaluate a large number of slab bridges, a first round of assessments is necessary to determine which bridges need a more detailed shear analysis. Also, a method to take into account transverse load redistribution in slabs is sought.To study the behavior of slabs in shear, a series of 26 slabs and 12 slab strips are tested until failure. The results of these experiments are compared to the beam shear capacity and the state-of-the-art in beam shear research to compare the shear behavior of beams and slabs. Recommendations for the shear assessment of slabs are formulated, and used to verify the shear capacity of 10 cases. This “Quick Scan” approach is compared to the AASHTO provisions, indicating that the “Quick Scan” approach is more conservative than the AASHTO provisions. However, the underlying target reliability index is significantly different for both approaches.For the existing bridges in the Netherlands, the proposed method can analyze a large number of cross-sections and thus help prioritize the efforts of the owners such that cases which need a more detailed shear analysis are identified.
  Authors: Lantsoght, Eva Olivia Leontien; van der Veen, Cor; Walraven, Joost; de Boer, Ane
  Authors: Lantsoght, Eva Olivia Leontien; van der Veen, Cor; Walraven, Joost; de Boer, Ane
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-0319
• Field Performance of Cost-Efficient Cast-in-Place and Precast Prestressed Bridge Approach Slabs
  Abstract: Concrete bridge approach slabs (BAS) are used at the interface between bridge abutments and pavements that rest on compacted embankment. Three solutions were presented in a previous study for the Missouri Department of Transportation, including two cast in place (CIP) designs for new construction and a novel precast prestressed slab (PCPS) designs for new construction and replacement of BASs. These solutions were estimated to have a lower cost of the designs, and an equal or better performance compared to the current MoDOT designs. Currently a new study has been initiated where the recommended BAS designs are being implemented in the field. The main purpose of the project is to study the field performance, costs and construction issues of these solutions. The primary objectives of the proposed project are to a.) Examine the construction issues and actual costs of construction and b.) perform a long term field monitoring of a PCPS slab and field testing of the proposed designs. The research presented in this paper addresses all the three aspects of the study. This paper presents results from field monitoring of the PCPS BAS using strain and moisture gages, field load testing of both PCPS and CIP slabs and compares costs of construction with projected values. Based on the observations thus far the BASs constructed are performing very well and have met or reduced costs of construction.
  Authors: Thiagarajan, Ganesh; Nalagotla, Jitesh; Muncy, Nathan P; Myers, John J.; Halmen, Ceki
  Authors: Thiagarajan, Ganesh; Nalagotla, Jitesh; Muncy, Nathan P; Myers, John J.; Halmen, Ceki
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-1998
• Service and Ultimate Limit State Flexural Behavior of One-Way Concrete Slabs Reinforced with Corrosion-Resistant Reinforcing Bars
  Abstract: This paper presents results of an experimental investigation to study the structural performance and deformability of a concrete bridge deck reinforced with corrosion resistant reinforcing (CRR) bars, i.e., bars that exhibit improved corrosion resistance when embedded in concrete as compared to traditional black steel. Flexural tests of one-way slabs were conducted to simulate negative transverse flexure over a bridge girder as assumed in the commonly employed strip design method. The bar types studied were Grade 60 (uncoated), epoxy-coated reinforcing (ECR, Grade 60), Enduramet 32 stainless steel, 2304 stainless steel, MMFX2, and glass fiber reinforced polymer (GFRP). The experimental program was designed to evaluate how a one-to-one replacement of the Grade 60 with CRR, a reduction of concrete top clear cover, and a reduction in rebar quantities in the bridge deck top mat influences flexural performance at service and ultimate limit states. The MMFX2 reinforced slabs exhibited the highest flexural strength because of the correspondingly high steel yield stress. Crack widths in the CRR specimens at service loads were consistent with the Grade 60 control except for the GFRP tests which resulted in cracks approximately twice as wide as the Grade 60 control. A reduction in CRR rebar quantities produced flexural behavior consistent with Grade 60, regardless of the higher yield strengths in CRR specimens. Increasing bar spacing resulted in larger crack widths, whereas decreasing concrete clear cover reduced crack widths. Moment-curvature predictions from the computer-based sectional analysis program Response 2000 were consistent with the tested results, demonstrating its viability for use with high strength and non-metallic rebar without a defined yield plateau.Deformability of the concrete slab-strip specimens was defined with ultimate-to-service level ratios of midspan deflection and curvature. The MMFX2 and Enduramet 32 one-to-one replacement specimens had deformability consistent with or higher than the Grade 60 controls, demonstrating that bridge deck slabs employing high strength rebar without a defined yield plateau can still provide more than sufficient ductility at an ultimate limit state. The GFRP and 2304 one-to-one replacement specimens had less deformability than the Grade 60 control and further consideration is needed to identify a viable bridge deck reinforcing scheme for this bar type. A reduction in rebar quantity and cover provided an acceptable level of ductility for the 2304 specimens and MMFX2 reinforced slabs, however reserve strength should be provided to accommodate moment redistribution at an ultimate limit state.
  Authors: Bowen, Galo; Zheng, Paul; Moen, Cristopher D.; Sharp, Stephen R.
  Authors: Bowen, Galo; Zheng, Paul; Moen, Cristopher D.; Sharp, Stephen R.
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-3314
• Design Model for Confinement Reinforcement in Pretensioned Concrete I-girders
  Abstract: The 2007 AASHTO LRFD Bridge Design Specifications contain prescriptive requirements for the quantity and placement of confinement reinforcement located in the bottom bulb of pretensioned concrete I-girders. This paper proposes a model that can be used to design confinement reinforcement as an alternative to the prescriptive requirements of AASHTO. The model considers a wide range of conditions and variations, yet is intended to be practical enough for use by bridge design engineers. Variables in the design model include: flange and bearing geometry, strand size and placement, effective prestress force, concrete and steel material properties, and the effects of steel bearing plates. The model is based on strut-and-tie and shear-friction concepts and considers the lateral-splitting failure mode. Derivation of the model is presented, and the model is compared to experimental results from the published literature.
  Authors: Ross, Brandon E.; Hamilton, H. R.; Consolazio, Gary
  Authors: Ross, Brandon E.; Hamilton, H. R.; Consolazio, Gary
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-3724
• Assessment of Shear Capacity of Existing Reinforced-Concrete Solid Slab Bridges
  Authors: Lantsoght, Eva
  Authors: Lantsoght, Eva
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-0319
• Field Performance of Cost-Efficient Cast-in-Place and Precast Prestressed Bridge Approach Slabs
  Authors: Thiagarajan, Ganesh
  Authors: Thiagarajan, Ganesh
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-1998
• Service and Ultimate Limit State Flexural Behavior of One-Way Concrete Slabs Reinforced with Corrosion-Resistant Reinforcing Bars
  Authors: Moen, Cristopher
  Authors: Moen, Cristopher
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-3314
• Design Model for Confinement Reinforcement in Pretensioned Concrete I-girders
  Authors: Ross, Brandon
  Authors: Ross, Brandon
  Year: 2013
  Document Type: Presentation
  Subject: Bridges and Other Structures; Design
  Session: 628
  Paper Number: 13-3724