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Therefore, when concreting at cold temperature cannot be avoided, it is essential to have a minimum curing time at a temperature sufficiently above the freezing point of the concrete pore water, so that the early strength of concrete is high enough to resist the inner tensile stress caused by water freezing. [5]
If the surface of the concrete pour is insulated from the outside temperatures, the heat of hydration will prevent freezing. The American Concrete Institute (ACI) definition of cold weather placement, ACI 306, [129] is: A period when for more than three successive days the average daily air temperature drops below 40 °F (~ 4.5 °C), and
Frost weathering is a collective term for several mechanical weathering processes induced by stresses created by the freezing of water into ice. The term serves as an umbrella term for a variety of processes, such as frost shattering, frost wedging, and cryofracturing.
Photograph taken 21 March 2010 in Norwich, Vermont. Frost heaving (or a frost heave) is an upwards swelling of soil during freezing conditions caused by an increasing presence of ice as it grows towards the surface, upwards from the depth in the soil where freezing temperatures have penetrated into the soil (the freezing front or freezing boundary).
The tremie concrete placement method uses a vertical or nearly vertical pipe, through which concrete is placed by gravity feed below water level. [4]The lower end of the pipe is kept immersed in fresh concrete so that concrete rising from the bottom displaces the water above it, thus limiting washing out of the cement content of the fresh concrete at the exposed upper surface.
Polymers in Concrete. CRC Press. pp. 40–42. ISBN 9780849348150. J. Marchand; Michel Pigeon; M. Setzer (1997). Freeze–thaw Durability of Concrete. Proceedings of the International Workshop in the Resistance of Concrete to Scaling Due to Freezing in the Presence of De-icing Salts, Sainte-Foy, Québec, Canada. Taylor & Francis. ISBN 9780419200000
Weather Underground / HeavyWeather Uploader, commonly WUHU, is a free software package for Microsoft Windows which allows users with Personal Weather Stations to contribute weather data to one of several networks, including: Weather Underground (wunderground.com) Citizen Weather Observer Program (also known as CWOP) [1] WeatherBug [2] YoWindow [3]
For Post and Lintel System ICFs, the concrete has a horizontal member, called a lintel, only at the top of the wall (Horizontal concrete at the bottom of the wall is often present in the form of the building's footer or the lintel of the wall below.) and vertical members, called posts, between the lintel and the surface on which the wall is ...