SIMULATION OF THE EFFECT OF DECK CRACKING DUE TO CREEP AND SHRINKAGE IN SINGLE SPAN PRECAST/PRESTRESSED CONCRETE BRIDGES by SUDARSHAN C KASERA B.E., SHRI RAMDEOBABA KAMLA NEHRU ENGINEERING COLLEGE, 2008 NAGPUR, INDIA A THESIS submitted in partial fulfillment of the requirements for the degree MASTER OF SCIENCE IN CIVIL ENGINEERING Department of Civil and Architectural Engineering and Construction Management College of Engineering and Applied Sciences UNIVERSITY OF CINCINNATI Cincinnati, OH 2014 Committee Chair: Richard Miller, Ph.D. Committee Members: Gian Andrea Rassati, Ph.D. Ala Tabiei, Ph.D. Abstract The use of precast/prestressed concrete as a structural building system became prominent in the 1950s especially for bridges. The design of the bridge structures was done as simply supported then. In 1969, an analysis and design method for ‘continuous for live load’ bridges was developed. Extensive research has been conducted since then to study the behavior of ‘continuous for live load’ precast/prestresed bridges and various modifications have been proposed. The current analysis method fails to predict the behavior of the continuous precast/prestressed bridge accurately because of the complex loads such as creep and shrinkage. The experimental procedure to determine the behavior of structures due to creep and shrinkage needs time and lot of resources. The motivation behind the current research is to provide a concept where finite element method can be employed to study the behavior of such structures. This research focuses on studying the behavior of single-span precast prestressed bridge due to long-term loading such as creep and shrinkage. The general purpose finite element program, ABAQUS 6.11-2 is used for analysis in the current project. The concept developed from the current research can be applied to multi-span bridge continuous structure in the future. The effect of creep and shrinkage on the overall system is studied. The results obtained from the analyses conform to the observed behavior in the field. It can be said that the analyses procedure for ‘continuous for live load’ bridges needs to account for the cracking of the deck slab to predict an accurate behavior of the structure. iii Table of Contents Acknowledgements ....................................................................................................................... xii Dedication .................................................................................................................................... xiii Chapter 1. Introduction ................................................................................................................... 1 1.1 Concept of ‘continuous for live load’ bridges ...................................................................... 3 1.2 Motivation for the research ................................................................................................... 5 Chapter 2. Background and Literature Review............................................................................... 7 2.1 PCA Research ....................................................................................................................... 8 2.2 NCHRP Report 322 (Oesterle et al. 1989) ......................................................................... 12 2.3 NCHRP Report 519 (Miller et al. 2004) ............................................................................. 14 2.3.1 Analytical study ........................................................................................................... 16 2.3.2 Experimental study on stub specimen .......................................................................... 17 2.3.3 Study of full-size specimens ........................................................................................ 19 2.3.4 Finite element study using ANSYS ............................................................................. 21 2.3.5 Conclusions made from the study ................................................................................ 21 2.4 Eldhose Stephen Thesis (2006), University of Cincinnati, OH .......................................... 22 2.5 NYSDOT Bridge Deck Task Force Evaluation of Bridge Deck Cracking on NYSDOT Bridges (Curtis 2007) ................................................................................................................ 24 2.6 Behavior of pre-stressed concrete bridge girders due to time dependent and temperature effects (Debbarma and Saha 2011) ........................................................................................... 27 2.7 Field monitoring of positive moment continuity detail in a skewed prestressed concrete bulb-tee girder bridge (Okeil et al. 2013) ................................................................................. 31 Chapter 3. Finite Element Modeling and Analysis ....................................................................... 34 3.1 Use of consistent units ........................................................................................................ 35 3.2 Modeling of geometry in the parts module ......................................................................... 35 3.3 Defining and assigning material properties to different parts of the structure ................... 38 3.3.1 Steel .............................................................................................................................. 39 3.3.1.1 Reinforcement and strand steel ............................................................................. 39 3.3.2 Concrete ....................................................................................................................... 39 iv 3.3.2.1 Concrete material model ....................................................................................... 39 3.3.2.2 Girder concrete...................................................................................................... 43 3.3.2.3 Deck concrete........................................................................................................ 44 3.4 Assembly ............................................................................................................................ 44 3.5 Defining steps and loadings ................................................................................................ 48 3.5.1 Steps ............................................................................................................................. 49 3.5.2 Dead load ..................................................................................................................... 50 3.5.3 Creep and shrinkage ..................................................................................................... 50 3.5.3.1 ACI – 209 Report .................................................................................................. 51 3.5.3.1.1 Correction factor for creep and shrinkage coefficient for girder and deck .... 53 3.5.3.2 User subroutine to calculate creep and shrinkage strain ....................................... 56 3.5.4 Live load ...................................................................................................................... 57 3.6 Field output requests ........................................................................................................... 57 3.7 Submission of job for analysis ............................................................................................ 57 3.8 Post processing in ABAQUS using the visualization module ............................................ 58 Chapter 4. Analysis approach ....................................................................................................... 60 4.1 Nonlinearity and Convergence ........................................................................................... 60 4.1.1 Newton-Raphson Method in ABAQUS (Hibbitt et al. 2011a) .................................... 61 4.2 Convergence issues in the model ........................................................................................ 66 4.3 Solution to the convergence issues ..................................................................................... 69 Chapter 5. Results and Discussion ................................................................................................ 71 5.1 Effect of girder age on prestressing force in the strands ..................................................... 87 Chapter 6. Conclusions and Future Research ............................................................................... 92 6.1 Future research .................................................................................................................... 93 References or Bibliography .......................................................................................................... 95 Appendix A. Validation model for creep and shrinkage subroutine ............................................ 97 Appendix B. Volume to surface ratio for the girder and the deck .............................................. 100 Appendix C. FORTRAN subroutine........................................................................................... 102 Appendix D. Script file for submission of job to the supercomputer ......................................... 104 v Appendix E. MS Excel Macro to create plots............................................................................. 107 vi List of Figures Figure 1.1 Percentage of bridges built annually with three major construction materials