306.1R-90 Standard Specification for Cold Weather Concreting

1 This document has been approved for use by agen-cies of the Department of Defense and for listing in DoD Index of Specifications and Standards.(Reapproved 2002) Standard Specification for Cold Weather Concreting ( )Reported by ACI Committee 306 Nicholas J. Carino, Chairman*Fred Anderson*Peter AntonichGeorge R. U. BurgOleh B. CiukDouglas J. Haavik*Gilbert HaddadJules HoudeDavid A. HuntRobert A. KelseyAlbert W. KnottCharles J. KorhonenWilliam Perenchio*John M. ScanlonMichael ShydlowskiBruce A. SuprenantJ. Derle ThorpeValery TokarLewis H. Tuthill*Harold B. WenzelArthur T. WintersThis Standard Specification gives requirements for cold Weather con-creting. It includes cold Weather requirements for preparations priorto placement of concrete, and protection of : accelerating admixtures; cold Weather ; compressive strength; con-struction; curing; formwork; freezing; heating; insulation; maturity; protec-tion; This foreword is included for explanatory pur-poses only.

2 It does not form a part of the StandardSpecification ACI Standard Specifications ACI is a ReferenceStandard which the Architect/Engineer may cite in theProject Specifications for any building project, to-gether with supplementary requirements for the spe-cific Each technical section of Standard SpecificationACI is written in the Three-Part Section Formatof the Construction Specifications Institute, as adaptedby ACI and modified to ACI requirements. The lan-guage is generally imperative and Checklists do not form a part of Standard Spec-ification ACI Checklists are to assist the Archi-tect/Engineer in properly choosing and specifying anynecessary requirements for the Project TO Specification CHECKLISTPl.

3 Standard Specification ACI is intended tobe used by reference or incorporation in its entirety inthe Project Specifications. Individual sections, articles,or paragraphs shall not be copied into the ProjectSpecifications, since taking them out of context maychange their meaning.*Task force for ACI Revised by the Expedited Standardization Proce-dure, effective July 1, 1990. In 1990, the format was revised. The Foreword,Preface, and Specification Checklist were revised. Reference Standards wereupdated and the sections on Materials and Execution were rewritten and If sections or parts of Standard SpecificationACI are edited into project specifications or anyother document, they shall not be referred to as ACIS tandards, since the Standard Specification has Building codes set minimum requirements neces-sary to protect the public.

4 This Standard Specifica-tion may stipulate requirements more restrictive thanthe minimum. Adjustments to the needs of a particularproject shall be made by the Architect/Engineer by re-viewing each of the items in the Specification Check-list and then including the Architect/Engineer s deci-sion on each item as a mandatory requirement in theProject These mandatory requirements designate thespecific qualities, procedures, materials, and perfor-mance criteria for which alternatives are permitted orfor which provisions were not made in the StandardSpecification. Exceptions to the Standard Specifica-tion shall be made in the Project Specifications, if A statement such as the following will serve tomake Standard Specification ACI a part of theProject on shall conformto all requirements of ACI , Standard Spec-ification for Cold Weather Concreting , publishedby the American Concrete Institute, Detroit,Michigan, except as modified by the requirementsof these Contract The Standard Specification Checklist identifiesArchitect/Engineer choices and alternatives.

5 Thechecklist identifies the sections, parts, and articles ofthe Standard Specification and the action required bythe 100 2002, American Concrete Institute. All rights reserved includ-ing rights of reproduction and use in any form or by any means, including themaking of copies by any photo process or by any electronic or mechanical de-vice, printed or written or oral, or recording for sound or visual reproductionor for use in any knowledge or retrieval system or device, unless permission inwriting is obtained from the copyright ACI STANDARDSPECIFICATION CHECKLISTM. MANDATORY REQUIREMENTSS ection/Part/Article ofACI Notes to the Reference standardsReview applicability of the cited references and take exception if Preparation before concretingIf the temperature of massive embedments, such as heavy steel guide rails or channels and steel grate framesor ducts, is lower than 32 F, concrete cast around them will be damaged by freezing.

6 Identify in the ContractDocuments massive embedments which must be at a temperature above freezing prior to placement of frozen subgrade can lead to freezing of newly-placed concrete or foundation settlement upon subsequentthawing of the subgrade. Specify in the Contract Documents the depth to which frozen subgrade should bethawed prior to placement of concrete. Specify procedure to verify that subgrade has been thawed to Protection temperatureSpecify the frequency for recording the temperature but do not use a frequency lower than twice per 24-hr Protection for structural safetyIndicate in the Contract Documents the concrete strength required for each structural member before form re-moval or continued construction, or OPTIONAL REQUIREMENTSS ection/Part/Article ofACI Notes to the Detailed proceduresIndicate in the Contract Documents whether submittal, review, and acceptance of procedure is required.

7 Des-ignate degree of detail required in any submittal Curing concreteStrength gain may not continue after removal of the protection because of rapid drying in regions where thereare periods of cold, dry, windy Weather . Therefore, under these conditions, consideration should be given toextending the protection period in order to facilitate moist Protection temperatureSpecify the minimum protection temperature if different than Column 2 of Table Protection against freezingl Any changes in the concrete mix proportions for reducing the duration of the protection period to preventearly freezing should be submitted for review or For certain structures, the protection period may be reduced if, after 24 hr of protection, the compressivestrength of the in-place concrete is at least 500 psi.

8 The requirements for these structures are that they do notrequire early strengths, will undergo little or no freezing and thawing during construction and in service, andhave not been exposed to an external supply of moisture during the protection The minimum protection temperature specified in Table may be reduced provided that the protectionperiod is extended until the compressive strength of the in-place concrete is at least 500 Note that a compressive strength of 500 psi is only adequate to protect the concrete against damage from onecycle of freezing and The specified minimum protection periods are based on the assumption that additional curing will be speci-fied and provided, as needed, prior to putting the structure into service.

9 Longer protection periods may bespecified to assure that desired properties are developed prior to removal of SUBMITTALSS ection/Part/Article ofACI Notes to the Submittal of proceduresIf required, indicate to whom submittals will be Detailed proceduresMinimum procedures for placement, curing and protection of the concrete may follow the recommendationsin ACI 306R, Cold Weather Concreting . The details should include, but not be limited to, the following:lProcedures for protecting the subgrade from frost and the accumulation of ice or snow on reinforcement orforms prior to for temperature protection during of covering, insulation, housing, or heating to be provided.

10 Curing methods to be used during and following the protection of strength accelerating for verification of in-place strength. Procedures for measuring and recording concrete for preventing drying during dry, windy detailed procedures for those items of concern for the Weather Concreting Specification - General, p. - - - Reference - Reference - Submittal of procedures2- Materials, p. - Scheduling protection - Concrete3- Execution, p. - Preparation before - Concrete - Curing of - Protection of This Standard Specification covers require-ments for cold Weather Concreting and protection ofconcrete from freezing during the specified The provision of this Standard Specificationshall govern unless otherwise specified in the -DefinitionsThese definitions are to assist in interpreting the pro-visions of this - Accepted by or acceptable to the Archi- -The architect, engineer, archi-tectural firm, engineering firm, or architectural and en-gineering firm issuing Project Drawings and Specifica-tions.