ACI R Cold Weather Concreting. Reported by ACI Committee Nicholas J. Carino, Chairman*. Fred A. Anderson*. Peter Antonich. George R. U. Burg. distribution and storage media, without the written consent of ACI. . ACI R- 10 supersedes ACI R and was adopted and published October ACI R: Guide to Cold Weather Concreting. or performed as applicable only by individuals holding the appropriate ACI Certifications or equivalent.
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Corners and edges are particularly vulnerable during cold weather. Research on Placement and Early-Age Behavior.
Hydronic Heat Now in ACI Specification | Wacker Neuson
These times are only approximate, and spe- cific values should axi obtained for he concrete used on the job. A copy of the tempera- surface will have a lower strength and may be prone to ture readings should be included in the permanent job dusting and subsequent freeze-thaw damage if exposed. Iowa State University Press, Detroit, pp. This recommendation applies particularly to tion, it is usually not necessary to provide measures to mass concrete.
Hydronic Heat Now in ACI 306 Specification
If the discretion in deciding what is adequate for each partic- concrete is air entrained and properly cured, the ulti- ular circumstance. Concrete placed and surface temperature maintained at 50 F 10 C for 3 days on ground at 35 F 2 306 Table 7. For example, in-place testing elimi- and quantity of admixture, and the range of the curing nates the difficulty of trying to prepare test specimens temperature.
Heaters and ducts should be posi- Wood fiber, soft woods 3. Concrete that is placed at low sulting from the use of salamanders or other combus- temperatures [40 to 55 F 5 to 13 C ] afi protected tion heaters that exhaust flue gases into an enclosed against freezing and receives long-time curing, thus de- area, may be damaged by carbonation of the concrete. Carbon monoxide, which can expedite finishing in cold weather, but it will impair result from partial combustion, and high levels of car- long-term concrete properties.
Therefore, if concrete has during the presetting period and to minimize heat dis- been saturated during the protection period, it should sipation from surfaces where coils are not used. See Chapters 5 mum values should be made well before 306d tem- and 6.
However, water curing is not recommended and the entire recommended protection period. The protection that is provided should be 4. They also may have electric wires embedded 360r figures should be used.
If the coarse aggregate is dry 3. Concrete can be damaged The actual temperature at the concrete surface deter- by fire at any age.
Thus, tough, moistureproof cover material because wetting for all practical purposes, the effects of wind speed may will impair its insulating value. Wenzel The general requirements for producing satisfactory concrete during Chapter 3 – Temperature of concrete adi mixed cold weather are discussed, and methods for satisfying these require- and placed and heating of materials, p.
These tables and figures can also be 306g to deter- 7. See During periods not defined as cold weather, such as Chapter 9.
Cold Weather Concreting Reported by ACI Committee | Rajarondahaim Rajarondahaim –
On paulins should be arranged so that heated air can cir- the other hand, exposed horizontal surfaces, particu- culate freely on both the top and, where exposed, the larly finished floors, are prone to rapid drying in a bottom of the slab. There will be no early-age strength require- resulting in a weak dusty surface.
In to determine the level of strength development.
Concrete placed tended serviceability of the structure. For example, drying will be excessive used accelerating admixture that reduces sci setting if concrete at 50 F 20 C is exposed to air having 3066r time and increases the rate of early-age strength devel- temperature of 50 F 10 C and a relative humidity less opment.
The appropriate value for the datum and they offer advantages compared with testing field- temperature T O depends on the type of cement, the type cured specimens.
Several factors affect this time period, including ambient temperature, the type of concrete, size of the pour and how soon the 036r will be exposed to load conditions. One should take advantage of not be permitted to heat or to dry the concrete locally. Layers of insulating material placed heated enclosure.
The mixing temperature be substantially higher than air temperature during au- should not be more than 15 F 8 C above the recom- tumn, while the reverse may occur during spring.
Blanket 3006r live steam heating provides an ideal curing Mineral fiber, fibrous form environment, it offers less than ideal working condi- processed from rock, slag, cr glass 3. The protection periods given in Table 5. The fore being surrounded by fresh concrete at a tempera- air temperature is 20 F and the concrete at delivery ture of at least 55 F xci C.
Guide Updates and Field Applications. Concrete placed and surface temperature maintained at 50 F 10 C for 7 days Table 7. In addition, strict fire prevention measures should be enforced. To prevent packing at the end of the mixer, therefore, lower minimum placement temperatures are coarse aggregate 30r be added first.
For protection periods between 3 and 7 pliable blankets of foamed vinyl with an extruded vinyl days, interpolation between the values in the tables or backing.