1、1CraCks in a repairKeywords: cracking; cracks; durability; repair.QuestionShould cracks in a repair be of concern?AnswerIrrespective of their cause (for example, shrinkage, temperature, loads, reflection), cracks are of concern in repairs. nullirst, cracking provides direct avenues for the ingress o
2、f nullater and aggressive agents into the repair; therefore, cracking is alnullays a concern from a durability point of vienull. nullracks may also adversely affect the perfornullmance of repairs designed to carry load. nullinally, cracking may be of concern from an aesthetic point of vienull.Discus
3、sionnulloncrete repairs can be broadly classinulled into structural and nonstructural. Structural repairs are designed to participate in carrying load and to protect the underlying concrete and embedded reinforcing steel from deterionullration and corrosion. nullonstructural repairs are repairs desi
4、gned for protection andnullor aesthetic purposes only. nullhe presence of cracks may adversely affect the loadnullcarrying behavior of the repaired structure. nullhus, cracks in repaired portions of the structure may not be acceptable. In such cases, the effect of cracking on structural performance
5、of the repaired structure should be evaluated by the licensed design professional.nulloth types of repairs are intended to mitigate the ingress of potentially deleterious elements, such as nullater, chlorides, carbon dioxide, and sulfates, into the repair as nullell as into the existing concrete (nu
6、llig. null). nullracking is probably the biggest single factor in the overall durability of the repair, especially in harsh environments. nullrom a durability point of vienull, an ideal repair nullould have no cracks; honullever; in practice, the goal should be to miniminulle the amount and nullidth
7、 of the cracks.nulluidance on tolerable crack nullidths in concrete structures is presented in reports from nullnullI nullommittee nullnullnull, nullracking.nullnullnull nullhile these documents nullere developed for cracking in nenull concrete structures, the recommendations can be applied to concr
8、ete repairs. nulluidance on achieving cracknullresistant repairs can be found in documents prepared by the nullmerican nulloncrete Institute,nullInternational nulloncrete nullepair Institutenull,nulland null.S. nullrmy nullorps of nullngineers.nullSummarynullracking in a repaired portion of a concre
9、te structure may affect the repair ability to perform its intended function and may reduce the service life of the repaired structure. nullhe outcome largely depends on the extent, depth, and nullidth of cracks.Referencesnull. nullnullI nullommittee nullnullnull, nullnullontrol of nullracking in nul
10、loncrete Structures (nullnullI nullnullnullnullnullnullnull),nullnullmerican nulloncrete Insti nulltute, nullarmington nullills, nullI, nullnullnullnull, nullnullpp.null. nullnullI nullommittee nullnullnull, nullnullauses, nullvaluation, and nullepair of nullracks in nulloncrete Structures (nullnull
11、I nullnullnull.nullnullnullnullnullnullnulleapproved nullnullnullnull),nullnullmerican nulloncrete Institute, nullarmington nullills, nullI, nullnullnullnull, nullnullpp.null. nullnullI nullommittee nullnullnull, nullnullints in nulloncrete nullonstruction (nullnullI nullnullnull.nullnullnullnullnul
12、l nullnulleapproved nullnullnullnullnull),null nullmerican nulloncrete Institute, nullarmington nullills, nullI, nullnullnullnull, nullnullpp.null. nullnullI nullommittee nullnullnull, nullnulluide for the Selection of nullaterials for the nullepair of nulloncrete (nullnullI nullnullnull.nullnullnul
13、lnullnull),nullnullmerican nulloncrete Institute, nullarmington nullills, nullI, nullnullnullnull, nullnullpp.null. InullnullI, nullnulluidelines for Surface nullreparation for the nullepair of nulleteriorated nulloncrete nullesulting from nulleinforcing Steel nullorrosion (InullnullI nullnullnull.n
14、ullnullnull nullnull),nullInternational nulloncrete nullepair Institute, nullosemont, Inull, nullnullnullnull, nullpp.null. InullnullI, nullnulluidelines for Selecting and Specifying nulloncrete nullepair nullaterials (InullnullI nullnullnull.nullnullnull nullnull),null International nulloncrete nul
15、lepair Institute, nullosemont, Inull, nullnullnullnull, nullnullpp.ACI 364.9T-03(11)TechNoteAmerican Concrete Institute Copyrighted Materianullnullnull.concrete.org2 CRACKS IN A REPAIR (ACI 364.9T-03)null. nullaysburd, null. null.; nullmmons, null. null.; nullcnullonald, null. null.; nulloston, null
16、. null.; and nullesner, null. null., nullnullerformance nullriteria for nulloncrete nullepair nullaterials Summary nulleport,null Technical Report, nullnullnullnullnullnullSnullnullnull, null.S. nullrmy nullorps of nullngineers, nullicksburg, nullS, nullnullnullnull.Fig. 1: Concrete repair cracking-
17、failure interaction model (courtesy of Vaycon Consulting).CRACKS IN A REPAIR (ACI 364.9T-03) 3American Concrete Institute Copyrighted Materianullnullnull.concrete.orgReported by ACI Committee 364nulled null nullodnullnnullairnullnullrie null nullynchSecretarynullndall null nullardnullnoit nullssonne
18、ttenullristopher null nullonullnulluglas nullrkenullyan nullexander nullrrisnulluce null nullllinsnullian nulle nullpenullris nullagunskynullter null nullmonsnullul null nulludettenullimothy null null. nullllespienullreh null nullegoriannullnulln null nullptanullmes null nullnullnaldnullilliam null
19、nullshnully null nullulnull nullm Shiunullomas null Spencernullhn null nullannernullalery nullokarnullvid null nullannullkernullexander null nullaysburdnullrt null. von nullynullmes nullarnernullvid null. nullitmorenullhn null nullusfeldnulln nullffronnullbert null nullnrynulll null nullndonullarles
20、 null nullokhamnullhok null nullkadenullmes null nullspernullory null nullmpnullith null nullsnernullick null nullrsonnullhn S. nullndnullitpal S. nullngatSurendra null nullnnullekarConsulting memnullersnullbert null. nullveckerStephen null nullhansonnullnullrd null nullnullon null.nulleilan Songnul
21、lla nullarmabalanullbert nullracynullilliam null. nullescottnullnullI nullechnullotes are intended for reference for the design and construction of concrete structures. nullhis document is intended for the use of individuals nullho are competent to evaluate the significance and limitations of its co
22、ntent and nullho nullill accept responsibility for the application of the information it contains. nullhe nullmerican nulloncrete Institute disclaims any and all responsibility for the accuracy of the content and shall not be liable for any loss or damage arising therefrom. nulleference to this docu
23、ment shall not be made in contract documents.nullI nullnullnullnullnullnulls adopted and published nullly nullnull.nullpyright nullnullnull, nullerican nullncrete Institute.nullll rights reserved including the rights of reproduction and use in any form or by any means, including the making of copies
24、 by any photo process, or by electronic or mechanical device, printed, nullitten, or oral, or recording for sound or visual reproduction or for use in any knonulledge or retrieval system or device, unless permission in nulliting is obtained from the copyright proprietors.For additional copies, please contact: American Concrete Institute, 38800 Country Club Drive, Farmington Hills, MI 4833null nullone: null8null48nullnull0, Fanull 348null48nullnullnull nullnullnullconcretenullorg
