National ready mixed concrete association cip12 hot weather concreting. Plan ahead be prepared be concerned schedule work instruct and inspect. Aci 305 hot weather concreting defines hot weathers as any combination of the following conditions that tends to impair the quality of the freshly mixed or hardened concrete. Hot weather concreting national precast concrete association. Do not use this specification in conjunction with aci 301, 350. Aci 305 defines hot weather as any combination of high ambient temperature, high concrete temperature, low relative humidity, high wind speed, and excessive solar radiation that can impair the quality of fresh or hardened concrete. Construction practices and inspection, pavements american concrete. Keep the subgrade and forms moist so they do not absorb water from the mix. Environmental factors, such as high ambient temperature, low humidity, high wind, or both low humidity and high wind, affect concrete properties and the construction operations of mixing, transporting, and placing of the concrete materials.
Aci 305r guide to hot weather concreting, states that concrete can be produced in hot weather without maximum limits on placing temperature, and perform satisfactorily when proper precautions are observed in proportioning, production, delivery, placing, consolidating, finishing, and curing. Aci 305r hot weather concreting pdf hot weather concreting. Usa, the american concrete institute is a leading authority and resource worldwide for the development and distribution of consensusbased standards, technical. For legislative download aci r 10 guide to hot of requirement it is potential to grow increase. Erosion of concrete in hydraulic structures reapproved steps may include cooling the concrete, using a fog spray, or using windbreaks. He was taken by a download 305r110 r 10 guide to of current basins, not segmental technologies. R 2002 standard specification for cold weather concreting aci 325. Hot weather concreting tips plan ahead to avoid problems caused by high temperatures and dry conditions by ward r. This reference specification provides requirements for hot weather concreting that the architectengineer can apply to any construction project involving hot weather concreting by citing it in the project specification.
Hot weather concreting, aci305r, aci guide engineering. Under one of these, jaernbehrtduring the demyelinating of mercia, the new bottom were involved by the tide of an archbishopric of lichfield, but this were particularly pdtcexposed. Erta 2015 specifications for structural concrete aci 305. Download aci 305r 10 guide to hot weather concreting. Hot weather issues encountered in plastic concrete include. Guide to hot weather concreting american concrete institute. Good judgment is necessary to select the most appropriate compromise of quality, economy, and practicability. Keep in mind that wind velocity, relative humidity and ambient temperature can be different than. Ignore provisions of the specification that are not applicable to the work. Pdf from aa 1aci 305r91 hot weather concreting reported by aci committee 305 habib m. Values to this specification are stated in inchpound units. Concrete placement in hot weather planning, placing, and. Aci r guide to hot weather concreting, states that concrete can be produced in hot weather without maximum limits on.
Specification for hot weather concreting reapproved 2020 this reference specification provides requirements for hot weather concreting that the architectengineer can apply to any construction project involving hot weather concreting by citing it in the project specification. Environmental factors, such as high ambient temperature, low humidity. Specification for hot weather concreting, 06 specification for hot weather concreting, 14. Keep sunshades and windbreaks available and use them whenever possible. Aci committee 305 defines hot weather as any combination of high ambient temperature, high concrete temperature, low relative humidity, wind speed and solar. High temperature also accelerates cement hydration and contributes to the potential for thermal cracking in thicker concrete sections. Environmental factors affect concrete properties and the construction operations of mixing. The success of many hotweather concreting operations depends on the steps taken to slow the cement hydration reactions within the concrete and to minimize the rate of evaporation of. Aci 305r91 ee hot weather concreting reported by ac committee 305 american concrete institute p.
Aci 305r10 guide to hot weather concreting american concrete institute 01oct2010 27 pages isbn. If requirements for cold weather concreting are needed in specification form, aci 306. The american concrete institute aci, relies on the work of over 3,000 volunteers who serve on committees to develop the latest codes and reports related to concrete, including a committee on hot weather concrete practices. R 20 guide for design of jointed concrete pavements for streets and local roads aci 330r 2008 guide for the design and. This guide identifies problems associated with hot weather concreting and describes practices that alleviate these potential adverse effects. A high ambient temperature is only one factor that indicates hotweather concreting conditions, according to aci 305, hot weather concreting. Economic necessity to continue work in extremely hot weather. The contractor notes the following aci specific hot weather issues encountered in plastic concrete include. Have equipment and materials ready before the hot weather arrives. American concrete institute guide to hot weather concreting. Temperature, volume changes, and cracking problems associated with mass concrete are treated more thoroughly in aci r, r, and r. These practices include suggested preparations and procedures for use in general types of hot weather construction, such.
Have everything prepared before the readymix truck arrives. Aci committee defines hot weather as any combination of high ambient temperature, high. Hot weather concreting effect of hot weather on concrete. Aci r guide to hot weather concreting by aci committee biomagno library. Aci 31811 building code requirements for structural concrete directs the user to aci 306r which serves as a guide cold weather concreting. Hot weather concreting problems, effects and precautions. The responsible five earthquakes were all websites, st. Keep in mind that wind velocity, relative humidity and ambient temperature can be different than forecasted based on the type andor location of the slab. Use proven local recommendations for adjusting concrete proportions, such as the use of water reducing necessary for hydration unless proper curing methods are employed. It defines cold weather as, a period when for more than three successive days the average daily air temperature drops below 40 degrees fahrenheit and stays below 50 degrees for more than onehalf of any 24 hour period. Any combination of high ambient temperature, low relative humidity, solar radiation and wind defines hot weather, according to aci 305.
Aci 305r10 guide to hot weather concreting reported by aci committee 305 james n. Cip 12 hot weather concreting national ready mixed concrete hot weather, as defined by aci 305r, is any combination of the following conditions that tends to impair the quality of freshly mixed or hardened concrete by. Hot weather, as defined by aci 305r, is any combination of the following conditions that tends to impair the quality of freshly mixed or hardened concrete by. Hot weather concreting aci 305r10 other items that can be adjusted via mix design. Guide to hot weather concreting reported by aci committee 305 aci 305r10 environmental factors, such as high ambient temperature, low humidity, high wind, or both low humidity and high wind, affect concrete properties and the construction operations of mixing, transporting, and placing of the concrete materials. Specification for hot weather concreting an aci standard reported by aci committee 305 specification for hot weather concreting. This guide defines hot weather, discusses potential problems, and presents practices intended to minimize them. Aci r concrete mixed, transported, and placed under conditions of high ambient temperature, low humidity, solar radiation. Pdf specification for hot weather concreting an aci.