1、An ACI Technical Publication SYMPOSIUM VOLUME SP-304 Sustainable Performance of Concrete Bridges and Elements Subjected to Aggressive Environments: Monitoring, Evaluation, and Rehabilitation Editors: Yail J. Kim Baolin Wan Isamu YoshitakeSustainable Performance of Concrete Bridges and Elements Subje
2、cted to Aggressive Environments: Monitoring, Evaluation, and Rehabilitation SP-304 Editors: Yail J. Kim Baolin Wan Isamu Yoshitake Discussion is welcomed for all materials published in this issue and will appear ten months from this journals date if the discussion is received within four months of t
3、he papers print publication. Discussion of material received after specified dates will be considered individually for publication or private response. ACI Standards published in ACI Journals for public comment have discussion due dates printed with the Standard. The Institute is not responsible for
4、 the statements or opinions expressed in its publications. Institute publications are not able to, nor intended to, supplant individual training, responsibility, or judgment of the user, or the supplier, of the information presented. The papers in this volume have been reviewed under Institute publi
5、cation procedures by individuals expert in the subject areas of the papers. Copyright 2015 AMERICAN CONCRETE INSTITUTE 38800 Country Club Dr. Farmington Hills, Michigan 48331 All rights reserved, including rights of reproduction and use in any form or by any means, including the making of copies by
6、any photo process, or by any electronic or mechanical device, printed or written or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device, unless permission in writing is obtained from the copyright proprietors. Printed in the United States of
7、America Editorial production: Ryan Jay ISBN-13: 978-1-942727-47-7 First printing, October 2015Preface Since the major milestones of sustainability, such as the Hannover Principle in 1991 and the Kyoto Protocol in 1997, the concept of sustainability has been broadly adopted by various disciplines. Ne
8、w construction consumes considerable amounts of energy and materials, and CO 2emission in 2020 is expected to increase by 100%, compared with that of today. Technical communities are responsible for improving the sustainability of the built-environment by using more durable and highly efficient mate
9、rials to reduce the need for replacement, maintenance, or repair. When subjected to aggressive environments, the performance of constructed concrete bridges and their elements is of interest from socioeconomic perspectives. Advances in a variety of aspects are required to achieve such a goal, includ
10、ing the durability of concrete members, performance monitoring technologies, evaluation methodologies, damage assessment, and structural rehabilitation. This Special Publication (SP) includes 10 papers selected from the three special sessions held at the ACI Fall convention in Washington, DC, Octobe
11、r 2014. Each submitted manuscript has been rigorously reviewed and evaluated by at least two experts. The editors wish to thank all contributing authors and anonymous reviewers for their endeavors. Yail J. Kim, Baolin Wan, and Isamu Yoshitake Editors University of Colorado Denver,Marquette Universit
12、y, and Yamaguchi UniversityTABLE OF CONTENTS SP-3041 Response Surface Metamodel-based Performance Reliability Reinforced for Concrete Beams Strengthened with FRP sheets 1 Authors: Junwon Seo, Yail J. Kim, and Shadi Zandyavari SP-3042 Reducing Deck Cracking in Composite Bridges by Controlling Long Te
13、rm Properties 21 Authors: Fatmir Menkulasi, Doug Nelson, Carin L. Roberts Wollmann, and Thomas E. Cousins SP-3043 Monitoring of the 205-ft long Pretensioned Precast Super Girders of the Alaskan Way Viaduct, Seattle, WA 41 Authors: Sameh S. Badie, David Chapman, Anthony Mizumori, Yu Jiang, Stephen J.
14、 Seguirant, and Bijan Khaleghi SP-3044 Using GFRP Reinforcing as a cost effective solution to extending the service life of bridge decks: A case study of the Kansas Department of Transportation I-635 Bridges over State Ave in Kansas City, KS 53 Authors: Ryan Koch and Jon Karst SP-3045 Analytical Mod
15、eling of Reinforced Concrete Beams Strengthened with Mechanically Fastened Fiber-reinforced Polymers (MF-FRP).65 Authors: Gordon Salisbury and Vicki Brown SP-3046 Use of Self-consolidating Concrete and High Volume Fly Ash Concrete in Missouri Bridge A7957 85 Authors: Eli S. Hernandez and John J. Mye
16、rs SP-3047 Managing ASR and DEF in Concrete Bridge Columns . 101 Author: Mark E. Williams SP-3048 Assessment of Early Corrosion in Prestressed Concrete Based on Open-Circuit Potential and Polarization Resistance .113 Authors: William Vlez and Fabio Matta SP-3049 The Role of Shrinkage Strains Causing
17、 Early-Age Cracking in Cast-in-Place Concrete Bridge Decks .123 Authors: Tayyebeh Mohammadi, Baolin Wan and Christopher M. Foley SP-30410 Finite Element Modeling of RC Beams Strengthened with Prestressed NSM CFRP Strips Subjected to Severe Environmental Conditions 141 Authors: Hamid Y. Omran and Raa
18、fat El-HachaSP-3041 1 Response Surface Metamodel-based Performance Reliability for Reinforced Concrete Beams Strengthened with FRP sheets Junwon Seo, Yail J. Kim, and Shadi Zandyavari Synopsis: This paper presents the performance reliability of reinforced concrete beams strengthened with fiber reinf
19、orced polymer (FRP) sheets, including structural fragility. Emphasis is placed on the development of effective strains that can represent FRP-debonding failure. The reliability predicted by a conventional standard log-normal cumulative probability density function and by the proposed response surfac
20、e metamodel (RSM) combined with Monte-Carlo simulation (MCS) is employed to assess the contribution of physical attributes to debonding failure. The models are constructed based on a large set of experimental database consisting of 230 test beams collected from published literature. Another aspect o
21、f the study encompasses the effect of various RSM parameters on the variation of effective strains, such as FRP thickness (t f ), steel reinforcement ratio ( ), concrete strength (f c ), beam height (h), beam width (w), span length (L), and shear span (a). The mutual interaction between these parame
22、ters indicates that those related to beam geometry (i.e., L, w, h, and a parameters) and the t fparameter are significant factors influencing the effective strain of FRP-strengthened beams. Keywords: debonding, effective strain, fiber reinforced polymer (FRP), fragility, performance reliability, res
23、ponse surface metamodel (RSM) Seo et al. 2 ACI member Junwon Seo is an Assistant Professor in the Department of Civil and Environmental Engineering at South Dakota State University, Brookings, SD. He is an associate member of ACI Committees 341 (Earthquake- Resistant Concrete Bridges), 343 (Concrete
24、 Bridge Design: Joint ACI-ASCE), and 345 (Concrete Bridge Construction, Maintenance, and Repair). His research interests encompass the structural behavior of irregular bridges and other structures, multi-hazard vulnerability and sustainability assessment, repair, retrofit and rehabilitation, structu
25、ral reliability and risk analysis, and structural health monitoring. He is a licensed Professional Engineer in Iowa. ACI member Yail J. Kim is an Associate Professor in the Department of Civil Engineering at the University of Colorado Denver, Denver, CO. He is the Chair of ACI Committee 345 (Concret
26、e Bridge Construction, Maintenance, and Repair) and is a member of Committees 342 (Evaluation of Concrete Bridges and Bridge Elements) and 440 (Fiber Reinforced Polymer Reinforcement). He also chairs ACI 440I (FRP-prestressed Concrete). His research interest includes the application of advanced comp
27、osite materials for structures, structural complexity, structural reliability, and science-based structural engineering, including and statistical and quantum physics. He is a licensed Professional Engineer in the Province of Ontario, Canada. ACI student member Shadi Zandyavari is a Graduate Student
28、 in the Department of Civil and Environmental Engineering at South Dakota State University, Brookings, SD. INTRODUCTION Structural fragility/reliability has been used for assessing seismic risk in constructed facilities such as highway bridges. Fragility (also known as vulnerability) is defined as a
29、 conditional probability that a structure exceeds a prescribed damage state when subjected to various levels of natural or man-made hazards. Reliability is, on the other hand, defined as the extent of achieving the given functionality of a structure exposed to distressful hazards. Previous studies h
30、ave shown that use of either empirical or analytical vulnerability functions can be regarded as one of the standard approaches for seismic fragility estimation 1-9, while analytical vulnerability functions are dominantly employed because in-situ data are limitedly available in most cases 1-6. Conven
31、tional methodologies for generating analytical vulnerability functions include the statistical extrapolation of a structures performance along with Monte Carlo simulation (MCS) 2-6. Seo et al. 5 estimated the structural fragility of steel moment- frame structures using MCS-based response surface met
32、amodels (RSM). The joint RSM-MCS method enables the efficient fragility assessments of a group of steel moment-frame structures when compared to the conventional methodologies. Ghosh et al. 6 utilized metamodels combined with MCS to evaluate existing bridges subjected to seismic load. Although the c
33、oncept of structural fragility and corresponding reliability are proven to be robust in evaluating the performance of civil structures, it has not fully been integrated into the resiliency appraisal of retrofitted structural members. Over the past couple of decades, fiber reinforced polymer (FRP) co
34、mposites have been used for enhancing the behavior of deteriorated reinforced concrete members, including several advantages such as favorable strength-to- weight ratio, non-corrosive characteristics, and reduced long-term maintenance costs 10. A number of studies on FRP-strengthening were concerned
35、 with the performance evaluation of various structural systems in static, fatigue, and seismic loadings 11. The reliability-oriented assessment of such a strengthening method was, however, rarely reported, particularly structural fragility accounting for critical failure modes such as FRP-debonding.
36、 This paper proposes a theoretical framework for examining the debonding vulnerability of reinforced concrete beams strengthened with FRP sheets. Of interest is a relationship between FRP-debonding and performance reliability. An RSM model was built using a large number of laboratory test data compi
37、led from published literature, encompassing geometric and material parameters, in order to predict the effective strain of FRP. It is worth noting that the effective strain controls the response of a strengthened beam in such a way that FRP-debonding failure takes place when the strain of the streng
38、thening system exceeds its effective strain. The experimentally validated RSM model coupled with MCS was implemented to generate the debonding fragility of FRP-strengthened beams, which was compared with a conventional fragility approach, followed by quantifying performance reliability. Response Sur
39、face Metamodel-based Performance Reliability for Reinforced Concrete Beams Strengthened with FRP sheets 3 RESPONSE SURFACE METAMODEL This section discusses the development of a prediction model for debonding strain of an FRP-strengthened beam based on a statistical approach and its validation agains
40、t experimental data. Development The RSM model proposed is a second-order polynomial function as shown in Eq. 1: 1 1 1 2 1 0 k i k i j j i ij k i i ii k i i i x x x x y (1) where y is the dependent variable representing the effective FRP strain of a strengthened beam at debonding failure; x iand x j
41、are the independent input variables dependent upon the geometric and material properties of the beam; 0 , i , ii , and ijare empirical coefficients to be determined by statistical analysis on test data; k is the number of input variables, and is the statistical bias. Such a statistical RSM model is
42、expected to generate a fragility curve for FRP- strengthened members at low computational expenses 5. A large set of database comprising 230 test beams was used to develop an RSM model, as listed in Table 1 where several parameters are presented: beam height (h), beam width (w), span length (L), she
43、ar span (a), compressive strength of concrete (f c ), thickness of FRP (t f ), and steel reinforcement ratio ( ). The effect of shear span (a) and shear-span-to-depth-ratio (a/d) on the flexure of the beams is basically identical from a fundamental mechanics standpoint. To identify the necessary sta
44、tistical coefficients of the parameterized model, the JMP software 12 was utilized for least-square analysis. Equation 2 is the refined format of the proposed RSM model (units are in mm and MPa) to predict the effective stain of an FRP-strengthened beam ( e ): 2 35 34 2 33 32 31 2 30 29 28 27 2 26 2
45、5 24 23 22 2 21 20 19 18 17 16 2 15 14 13 12 11 10 9 2 8 7 6 5 4 3 2 1 0 ave f f ave c c ave c c ave c c ave ave c c ave ave ave f f ave c c ave ave ave ave ave f f ave ave c c ave ave ave ave ave ave ave f f ave ave c c ave ave ave ave ave ave ave ave f f ave ave c c ave ave ave ave ave ave ave ave
46、 ave ave ave f f ave c c ave ave ave ave ave e t t f f f f f f a a f f a a a a t t f f a a t t h h f f h h a a h h h h h h t t w w f f w w a a w w w w h h w w w w t t L L f f L L a a L L L L h h L L w w L L L L t t f f a a h h w w L L (2) Table 2 exhibits the average properties of each RSM parameter
47、, while Table 3 summarizes the statistically determined RSM coefficients ( 0through 35 ). Validation Figure 1 shows a typical comparison between the experimental and predicted debonding strains (or effective strains) with respect to FRP thickness. With an increase in FRP thickness (t f ), the effect
48、ive strain of the strengthened beams was exponentially reduced. This observation can be explained by the fact that interfacial shear stresses along the bond-line of the beams augmented when an FRP thickness increased until the stress exceeded a critical stress that would result in FRP-debonding failure. Acceptable ag
