308.1-98 Standard Specification for Curing Concrete

1 ACI became effective April 1, 1998, American Concrete rights reserved including rights of reproduction and use in any form or by anymeans, including the making of copies by any photo process, or by electronic ormechanical device, printed, written, or oral, or recording for sound or visual reproduc-tion or for use in any knowledge or retrieval system or device, unless permission inwriting is obtained from the copyright proprietors. : This Specification provides requirements for alternative methodsfor Curing Concrete . These alternative methods are not necessarily equal ineffectiveness, cost, effect on project schedule, or impact on other aspects ofthe project. To use this Specification , the Architect/Engineer must not onlyinclude this document by reference in the project specifications, but mustalso identify the Concrete elements that are to be cured, and must choosethe method to be used to cure those elements.

2 This Specification hasinstalled default settings that may or may not be applicable to a specificproject. The Architect/Engineer is to use the Checklists included in thisspecification to customize the Specification to a specific project. Checklistsare provided in this document to guide the Architect/Engineer throughthese selection processes, and the selections must be included in the projectspecification. Alternatively, the Architect/Engineer may allow the contrac-tor the option of using one or more of a number of permissible Curing meth-ods, subject to review and approval. Further, the Architect/Engineer mustdetermine whether deliberate Curing efforts must or may terminate after apredetermined time has elapsed, or only after specified Concrete proper-ties have developed.

3 When deliberate efforts to cure the Concrete are to beterminated only when specified Concrete properties have developed, theArchitect/Engineer must also select the test method used to measure : cold-weather construction; Concrete ; Concrete construction; Curing ; Curing films and sheets; hot weather construction; insulating con-crete; insulation; membrane- Curing compounds; moist Curing ; moistureretention; sealers; water This foreword is included for explanatory purposesonly; it is not a part of Standard Specification ACI Standard Specification ACI is a Reference Stan-dard which the Architect/Engineer may cite in the ProjectSpecifications for any building project, together with supple-mentary requirements for the specific Each technical section of Standard Specification is written in the Three-Part Section Format of the Con-struction Specifications Institute, as adapted by ACI andmodified to ACI requirements.

4 The language is generallyimperative and Checklists do not form a part of Standard SpecificationACI Checklists are to assist the Architect/Engineer inproperly choosing and specifying the necessary mandatoryrequirements for the Project TO SPECIFICATIONS CHECKLISTP1. Standard Specification ACI is intended to beused by reference or incorporation in its entirety in theProject Specifications. Individual sections, articles, or para-graphs shall not be copied into the Project Specifications,since taking them out of context may change their Specificationfor Curing Concrete (ACI )ACI by ACI Committee 308 Kenneth C. Hover Chairman*Don Brogna*Samuel B. HelmsBryant Mather*Joseph CabreraEdward Peter Holub*David McDonald*James N. Cornell, II *Doug Hooton H.

5 Celik OzyildirimRonald L. DillyCecil L. JonesWilliam S. Phelan *Jerome H. FordFrank A. KozeliskiLuke M. SnellSteven H. Gebler*Richard W. Kriner*Joel TuckerGilbert J. HaddadJames A. Lee*John B. Wojakowski With assistance from Aimee Pergalsky and Bob Truitt* Members of Subcommittee contributing to this OF Concrete PRACTICEThe Specification is written to allow each method of curingto be a stand-alone Specification . The specifier is to deter-mine the desired results of the Curing and select the appropri-ate section or sections to achieve those results. Section 1shall be included with the selected sections. The specifier isto use ACI 308-92 Standard Practice for Curing Concrete ascommentary for making decisions within the checklists. Thealternative methods described in each section of this Stan-dard Specification are not necessarily equal in effectiveness,cost, effect on project schedule, or impact on other aspects ofthe project.

6 To use this Specification , the Architect/Engineermust not only include this document by reference in theProject Specifications, but must also review and respond tothe checklists. It is imperative that the Architect/Engineercustomize this Specification to meet the project requirementsthrough the checklists. The Architect/Engineer must identifythe Concrete elements that are to be cured, and must choosethe method to be used to cure them. Further, the Architect/Engineer must determine whether deliberate Curing effortsmust or may terminate after a predetermined time haselapsed, or only after particular levels of Concrete propertieshave developed. When deliberate efforts to cure the concreteare to be terminated only when particular Concrete propertieshave developed, the Architect/Engineer must also select thetest method used to measure those properties.

7 Checklists areprovided in this document to guide the Architect/Engineerthrough these selection processes, and the selections must beincluded in the Project of ACI to the Architect/Engineer shall review the referenced standards to ensure thepublished dates are applicable to the specific and the work that is to be cured as required by this Specification , or alter-nately, describe that work that is not to be cured in accordance with this spec-ification. Specify the elements for which this Specification does not Curing efforts may be terminated when either a predetermined timeperiod has elapsed, or when specific levels of Concrete properties have devel-oped in the Concrete in the field or in representative samples in the Architect/Engineer determines which of these criteria are to be employedin Paragraphs , , and the Architect/Engineer requires otherwise in the project specifications,Section will permit the use of any of the Curing methods described inSections 2 through 7 for unformed the Architect/Engineer requires otherwise in the project specifications,Section requires that for formed surfaces, absorbent forms be kept wetuntil removal.

8 Followed by the application of any of the Curing methods de-scribed in Sections 2 through 7 until duration or strength requirements are , , and Section 5 Fogging, as described in Section 5, may be specified. There may be insuffi-cient bleed water to maintain proper moisture conditions, or where little mois-ture loss can be tolerated. Concrete containing finely ground cements,expansive cement, fly ash, ground granulated blast furnace slag, silica fume,or other cementitious materials, or having a water-cementitious materials ratioless than by mass, may require fogging during the initial Curing can help to prevent plastic shrinkage MANDATORY Specification CHECKLISTP2. If sections or parts of Standard Specification are edited into project specifications or any other doc-ument, they shall not be referred to as ACI standards , sincethe Standard Specification has been Building codes set minimum requirements necessaryto protect the public.

9 This Standard Specification may stipu-late requirements more restrictive than the minimum. Ad-justments to the needs of a particular project shall be madeby the Architect/Engineer by reviewing each of the items inthe Specification Checklist and then including the Architect/Engineer s decision on each item as a mandatory require-ment in the Project These mandatory requirements designate the specificqualities, procedures, materials, and performance criteria forwhich alternatives are permitted or for which provisionswere not made in the Standard Specification . Exceptions tothe Standard Specification shall be made in the Project Spec-ifications, if A statement such as the following will serve to makeStandard Specification ACI a part of the Project Spec-ifications:Work on (Project Title) shall conform to all require-ments of ACI ( Standard Specification number withdate suffix and title) published by the American Con-crete Institute, Farmington Hills, Michigan, except asmodified by the requirements of these Contract The Standard Specification Checklists identify Archi-tect/Engineer choices and alternatives.

10 The checklists identifythe sections, parts, and articles of the Standard Specificationand the action required by the Architect/Engineer is to select the Curing period (Paragraph ) and themethod to be used to determine when deliberate Curing measures can be termi-nated (Paragraphs , , and ). Architect/Engineer must specify minimum length of time for the curingperiod under the non-tested criteria. The Architect/Engineer needs to considermixture proportions, environmental conditions, and skill levels of the contrac-tor in selecting Curing duration. The default value is 7 days. The Architect/En-gineer must determine acceptability of this value and must substitute a moreappropriate value as and the strength testing criteria, the Architect/Engineer must specify thecompressive strength that must be achieved by field-cured specimens prior totermination of deliberate Curing efforts.