ACI 345.1R-2016 Guide to Maintenance of Concrete Bridge Members.pdf

1、Guide to Maintenance of Concrete Bridge MembersReported by ACI Committee 345ACI 345.1R-16First PrintingSeptember 2016ISBN: 978-1-945487-21-7Guide to Maintenance of Concrete Bridge MembersCopyright by the American Concrete Institute, Farmington Hills, MI. All rights reserved. This material may not be

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10、tandards that it develops.Order information: ACI documents are available in print, by download, on CD-ROM, through electronic subscription, or reprint and may be obtained by contacting ACI.Most ACI standards and committee reports are gathered together in the annually revised ACI Manual of Concrete P

11、ractice (MCP).American Concrete Institute38800 Country Club DriveFarmington Hills, MI 48331Phone: +1.248.848.3700Fax: +1.248.848.3701www.concrete.orgThis guide addresses typical problems and cost-effective main-tenance techniques for highway bridges and their members, providing guidance to engineers

12、 and maintenance staff. Mainte-nance is crucial to a bridges lifespan and continued functionality, as well as to the public safety. Continuous and systematic mainte-nance of a bridge will extend its service life and reduce its overall operating cost.Concrete bridge maintenance is defined as those ac

13、tivities that are relatively inexpensive and repeatable, performed when a concrete member is still in good to fair condition, and are intended to prevent or minimize deterioration of the concrete. These activi-ties include sealing, washing, caulking, crack repair, and other minor repairs intended to

14、 prolong functionality of bridge members.This guide does not cover major rehabilitation, reconstruction, or bridge inspection. Detailed methods of repairing and inspecting bridges are referenced wherever necessary throughout the guide relative to the subject matter.Keywords: bridges; cementitious; c

15、oating; maintenance; placement; polymer; sealant.CONTENTSCHAPTER 1INTRODUCTION AND SCOPE, p. 21.1Introduction, p. 21.2Scope, p. 2CHAPTER 2DEFINITIONS, p. 2CHAPTER 3MAINTENANCE OF BRIDGES, p. 23.1Bridge maintenance, p. 23.2Limitations, p. 33.3Timing of maintenance, p. 3CHAPTER 4DETERIORATION OF BRIDG

16、ES, p. 34.1Deterioration indicators, p. 34.2Causes, p. 34.3Contributing factors, p. 4CHAPTER 5CONSIDERATIONS IN BRIDGE DESIGN, p. 65.1General, p. 65.2Decks and curbs, p. 65.3Deck joints, p. 75.4Superstructure, p. 85.5Substructures, p. 9CHAPTER 6DRAINAGE AND WASHING, p. 106.1General, p. 10Yail Jimmy

17、Kim, Chair Chris Carroll, SecretaryACI 345.1R-16Guide to Maintenance of Concrete Bridge MembersReported by ACI Committee 345Jesse L. BeaverMichael C. BrownAndrew J. FodenOliver K. GepraegsAlan B. Matejowsky*Rita K. OglesbyHarold R. SandbergJohan L. SilfwerbrandMichael M. SprinkelPaul J. St JohnRonal

18、d E. VaughnRichard E. WeyersMark Erik Williams*DeceasedConsulting MembersJames C. AndersonByron T. DanleyFouad H. FouadAllan C. HarwoodYash Paul VirmaniJeffrey P. WoutersACI Committee Reports, Guides, and Commentaries are intended for guidance in planning, designing, executing, and inspecting constr

19、uction. This document is intended for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations and who will accept responsibility for the application of the material it contains. The American Concrete Institute disclaims any and all res

20、ponsibility for the stated principles. The Institute shall not be liable for any loss or damage arising therefrom.Reference to this document shall not be made in contract documents. If items found in this document are desired by the Architect/Engineer to be a part of the contract documents, they sha

21、ll be restated in mandatory language for incorporation by the Architect/Engineer.ACI 345.1R-16 supersedes ACI 345.1R-06 and was adopted and published September 2016.Copyright 2016, American Concrete Institute.All rights reserved including rights of reproduction and use in any form or by any means, i

22、ncluding the making of copies by any photo process, or by electronic or mechanical device, printed, 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.16.2D

23、eck drainage, p. 106.3Washing exposed surfaces, p. 106.4Maintenance of deck drains, p. 106.5Other drain considerations, p. 11CHAPTER 7SEALING, p. 117.1General, p. 117.2Purpose, p. 117.3Sealing materials, p. 127.4Suggested areas for sealing, p. 127.5Recommended practice, p. 137.6Product selection, p.

24、 13CHAPTER 8MAINTENANCE PATCHING, p. 138.1General, p. 138.2Purpose, p. 148.3Selecting durable patching materials, p. 148.4Recommended patching procedures, p. 16CHAPTER 9JOINTS AND CRACKS, p. 169.1General, p. 169.2Maintenance of joints, p. 179.3Cracks, p. 179.4Crack repair, p. 179.5Joint caulking, p.

25、 19CHAPTER 10NOTABLE TECHNIQUES FOR BRIDGE MAINTENANCE, p. 1910.1General, p. 1910.2Corrosion inhibitors for use in maintenance, p. 1910.3Galvanic cathodic protection using sprayed zinc, p. 1910.4Discrete or spot anodes, p. 20CHAPTER 11SUMMARY, p. 20CHAPTER 12REFERENCES, p. 20Authored documents, p. 2

26、1CHAPTER 1INTRODUCTION AND SCOPE1.1IntroductionBridges represent a substantial investment of public funds and are expected to provide satisfactory performance and remain in service for many years. The longevity of constructed concrete bridges can be expected to be 75 to 100 years if proper maintenan

27、ce action is executed in a timely manner. Structural concrete members that deteriorate over time and eventually lose functionality could become life-threatening to the public. Aggressive environmental condi-tions for bridges involve cycles of freezing and thawing and wetting and drying with or witho

28、ut the presence of chloride. Corrosion of reinforcing steel will usually result in spalling of concrete cover and reduction of the cross-sectional area of the reinforcing steel, which reduces the strength of the member. The time required for deterioration to occur varies considerably, depending on s

29、everity of the exposure condi-tions and characteristics of structural concrete and rein-forcing steel. Traffic fatigue loading may become more dominant over time. Continuous and systematic mainte-nance of a bridge will extend its service life and reduce its overall operating cost. This guide present

30、s various technical aspects related to bridge maintenance, including the sources of deterioration and technical action that can improve the performance of existing bridge members.1.2ScopeThe contents discussed in this guide are classified into two categories: 1) deterioration of constructed bridges;

31、 and 2) maintenance activities to address potential problems asso-ciated with such bridges. The first category is dedicated to various distressful attributes influencing the performance of existing bridge members and their consequences, whereas the second category is concerned with timely preventive

32、 or corrective maintenance actions with an emphasis on drainage, sealing, patching, joint repair, and other relevant topics. The following is outside the scope of the present report: major rehabilitation, reconstruction, inspection, condition evaluation, and load rating.CHAPTER 2DEFINITIONSACI provi

33、des a comprehensive list of definitions through an online resource, https:/www.concrete.org/store/product-detail.aspx?ItemID=CT16. Definitions provided herein complement that source.bridge deckstructural concrete slab or other structure that is supported on the bridge superstructure and serves as th

34、e roadway or other traveled surface.damagevarious forms of disruption to a member (cracking, spalling, delamination, scaling, dissolution, and permanent deformation), such as result from environmental (freezing and thawing, erosion), chemical (alkali-silica reac-tion, sulfate attack), and physical (

35、impact, overload, fatigue) stresses that disrupt its intended condition and function.groutmixture of cementitious materials and water, or other binding medium such as magnesium phosphate or epoxy, often mixed with fine aggregate to form a thin, coarse mortar that can be poured into narrow cavities t

36、o fill them and consolidate the adjoining objects into a solid massoverlaylayer of hydraulic-cement concrete, mortar, or asphalt, seldom thinner than 1 in. (25 mm), placed on and usually bonded onto the worn or cracked surface of a concrete slab to either restore or improve the functionality of the

37、previous surface, also a layer of polymeric concrete usually less than 0.4 in. (10 mm) thick.superstructurepart of a bridge providing the horizontal span.CHAPTER 3MAINTENANCE OF BRIDGES3.1Bridge maintenanceInitial bridge deterioration occurs slowly and, therefore, is often overlooked. In later stage

38、s of deterioration, however, sudden catastrophic events could occur, demanding imme-diate action. Progressive deterioration can be slowed, and sometimes avoided, if proper systematic preventive mainte-American Concrete Institute Copyrighted Material www.concrete.org2 GUIDE TO MAINTENANCE OF CONCRETE

39、 BRIDGE MEMBERS (ACI 345.1R-16)nance is practiced (Carter and Kaufman 1990). Maintenance activities are often more cost-effective when the concrete is in relatively good condition (for example, structural members are sound with minor cracking or spalling). Main-tenance should focus on those parts of

40、 a structure that face the most severe exposure conditions and on those whose deterioration may have the greatest impact on the function-ality of the structure or the condition of adjacent members. Preventive maintenance focuses on the causes (as opposed to treatment) of potential deterioration and

41、its effects. For example, sealing the deck surface reduces the infiltration of chloride. Refer to ACI 546R for technical details for sealing procedures. Proper preventive maintenance activities can reduce the rate of deterioration, extend service life, and reduce future repair costs (Carter 1989a).

42、Responsive main-tenance activities such as treatments to existing deck prob-lems help to keep bridges operating safely and efficiently. These are treatments to existing deck problems.Concrete bridge maintenance involves relatively inexpen-sive, repetitive activities that either: 1) prevent or minimi

43、ze the deterioration of bridge members; or 2) extend the service of structural concrete members. Concrete bridge mainte-nance should be performed when the structural concrete member is still in excellent to fair condition, that is, has a condition appraisal rating of 5 (Federal Highway Admin-istrati

44、on 1995), including minor section loss, cracking, spalling, or scour, according to the nine-scale evaluation criteria of the National Bridge Inventory (Federal Highway Administration 1995). Maintenance can be subdivided into two categories: preventive and reactive.3.1.1 Preventive maintenanceProcedu

45、res performed before significant deterioration is noticed and the structural concrete member is still in good condition are called preven-tive maintenance. These procedures, which may be planned at a design stage, include washing, sealing, caulking, and minor crack repair.3.1.2 Reactive maintenanceP

46、rocedures performed in the early stages of the visible deterioration cycle, which are usually more extensive than preventive maintenance, are called responsive maintenance. These may include minor repairs, establishment of positive deck drainage systems, maintenance of deck joints, and similar activ

47、ities that extend the service life of structural concrete members in bridges. Responsive maintenance can also apply to nonstructural members.3.2LimitationsMaintenance is not effective when applied to improperly designed and constructed concrete bridge members. Exam-ples include inadequate or shallow

48、 concrete cover depths, and poor drainage characteristics that cause ponding.3.3Timing of maintenanceWhereas maintenance activities performed in a timely manner can be extremely cost-effective, the same activi-ties conducted after extensive damage has occurred could become a poor investment. The obj

49、ective of maintenance is to extend the service life of constructed concrete structures by controlling the extent of damage nucleation and propa-gation. Knowledge of concrete deterioration mechanisms is crucial to foresee structural damage before it occurs, at a time when the concrete is still repairable. Damage, such as scaling, reinforcing steel corrosion, or spalling is easy to observe after it has occurred. Foresight involves the ability to identify the signs and symptoms that precede the devel-opment of damage. For