Winter concreting, 2.24

Haddad, J.G. (1975). Conditions for the Production, Placing, and Curing of Winter Concrete, ACI Chapter Meeting, Ottawa. 

The water-reducing-accelerating admixtures may be used in winter concreting as they permit early form removal and enable concrete to be available for service earlier. The addition of these admixtures should result in an initial set one hour earlier, with a maximum at 3 A hours earlier. The compressive strength requirement is 125% of control mix at 3 days and 110% at 28 days. 

Figure 1.2. The names of the elements and thus the notation of the chemical equation is international. The figure shows a section of a page in a Japanese textbook on winter concreting.

Figure 2.41. Winter concreting requires a number of special measures to protect the esh and hardening concrete against freezing. Typical winter measures are the use of hot concrete and provision of heat insulation of concrete structures during hardening.

Danish Building Research Institute Winter Concreting, SBI Instruction 125, 1982. In Danish Statens Byggeforskningsinstitut Vinterstpbning af baton, SBI-anvisning 125, Statens Byggeforskningsinstitut 1982. 

The bitumen in the Athabasca deposit, which has a gravity on the API scale of 8°, is heavier than water and very viscous. Tar sand is a dense, soHd material, but it can be readily dug in the summer months during the winter months when the temperatures plunge to —45° C, tar sand assumes the consistency of concrete. To maintain acceptable digging rates in winter, mining must proceed faster than the rate of frost penetration if not, supplemental measures such as blasting are required. 

Floor Bare soil for planting with concrete walkway (floor area was covered with aluminum film at horizontal height of 3.5 m at winter nights) 756... 

There has been controversy over the use of calcium chloride in concrete containing embedded metal in view of the possibility of corrosion, particularly where the concrete is of a porous nature. Many countries have made provision in the relevant codes of practice to prevent or limit its use where steel reinforcement is present. This has renewed interest in chloride-free accelerators as replacements for calcium chloride in reinforced concrete. However, calcium chloride remains a most effective material for use in unreinforced concrete for economic production under winter conditions and its effects on concrete, whether beneficial or undesirable, are well researched and quantified. In some areas the newer non-chloride materials, although shown to reduce the likelihood of reinforcement corrosion, have not been widely studied and their other effects on concrete are less known. 

In the area of tidal concreting for sea defense work, e.g. between tides, the concrete is required to develop strength rapidly even under winter conditions. The advent of viscosity-enhancing admixtures (VEAs) which... 

In the winter months, significant benefits are derived from the use of concretes that contain cold-weather accelerating (CWA) admixtures with antifreeze properties. The economic benefits are derived from their ability... 

Partially roofed concrete tank containing chemical feed for unattended winter operation of pilot plant. 

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