b'THE OFFICIAL NFBA MAGAZINEcontinued from page: 17finishing activities.Since water evaporates soGuides from the American Concrete Institute.quickly during hot weather concreting, crackingReferencesof the fresh concrete while the concrete is still in the plastic stage is a common problem.AddingACI 302.1 R-15; American Concrete reinforcingfiberstotheconcretemixtureInstitute.Guide to Concrete Floor and Slab generally helps reduce plastic concrete cracking. Construction 76 pages.Photo 3: The timing and equipment used forACI 305 R-10; American Concrete Institute. RESEARCH & TECHNOLOGYfinishing varies by project based on weather,Guide to Hot Weather Concreting 23 pages.concrete specifications, and desired final effects.Concrete Curing ACI 306 R-16; American Concrete Institute. Concrete gains strength via a chemical reactionGuide to Cold Weather Concreting 23 pages.calledhydration.Duringhydration,majorACI 308 R-16; American Concrete Institute. compounds in cement are chemically bonded toGuide to External Curing of Concrete 36 water molecules to form the hydration productspages.that bind aggregates in place.In the absence ofFeldmann, T and A. Schambach (2016) Design water, hydration stops and concrete no longerof Slabs on Grade, Frame Building News, gains strength.For this reason, if water is allowed to evaporate too quickly from the surface of freshJanuary issue.concrete, a lower final concrete strength will result.More information regarding the Guides from It follows that hot weather concreting can resultACI:in a weak concrete floor if concrete is not kept moist during the curing process and kept as cool asAmerican Concrete Institutepossible while it cures.Cold weather concreting has38800 Country Club Drivea different set of challenges.The cold temperatureFarmington Hills, MI 48331will significantly slow the curing process.Concrete needs to cure for 24 to 36 hours so it can reach aPhone: +1.248.848.3700500-psi strength before it is allowed to freeze.IfFax: +1.248.848.3701cold weather concreting is done inside a buildingwww.concrete.org and the building is heated to keep the concrete from freezing, water can evaporate too quickly for the concrete resulting in weak concrete due toAbout the author: Joseph Zulovich, PhD is a lack of hydration as with hot weather concreting. Commercial Agricultural Engineer and Assistant Summary Extension Professor at the University of Missouri Slab on grade floors need to be both designed andExtension.constructed properly to obtain a quality result.This article focused on construction sequencing when concrete slabs are part of post-frame building. Concrete construction during normal weather was presented with additional aspects included to address adjustments needed during cold and hot weather concreting.Much more information on concrete construction is available in the various 18 / FRAME BUILDER -OCT2020'