The recent heavy snow in winter in northern weather, the minimum temperature is below -10 degrees Celsius in general, Xinjiang, Manchuria, Inner Mongolia, Zhang North and other regions even at temperatures below -20 degrees Celsius, how do we deal with low temperature, temperature difference on the tower foundation concrete How do we do? This has been our tower construction industry, common problems, the company's technology is hereby technical notes, only the Group departments and customers and friends around the reference.

Is simply to add rapid setting concrete powder, anti-freeze and heat conservation is crucial for good.

When the temperature of 0 ℃ and the construction should be used in ordinary portland cement, calcium silicate content of not less than 50%, fineness to 4900/cm2 breakdown of the screen margin <15% of the cement. This heat of hydration reaction of cement early, so early strength increases rapidly, the general strength of three days is approximately equal to 7 days ordinary portland cement strength, the better ones; to lower water-cement ratio, in fact, reduce the free water, increasing amount of cement, the rate of increase in 50kgf/m3 about more appropriate to increase the hydration heat, reduce the strength of growth in the short age so fast; mixed early strength agent and reducing agent, to improve the early strength, but the content must be tested to determine, weight measurement based on cement, not more than 5% of cement consumption, less waste of doped neither effect, but more content will reduce the intensity of an additional gas content. Concrete, adding 4% to 6% of the gas content, you can cut off the seepage channel, to form a coherent pore closed pores with each other, thereby enhancing the compactness and durability in concrete.

A heat storage method using

Mainly applied to temperature ≥ -15 ℃ and the structure of thick large-situ concrete works on the raw materials of sand and water heating of the concrete in the mixing, transportation and placement is completed. Also has considerable reserves of energy, in order to speed up the hydration heat, and to enhance the thermal insulation of concrete to keep the temperature down to 0 ℃ before the frost has some ability. Structure using the regenerative method should be thick and large volume, the smaller the exposed area, will be less heat loss through the surface, she has had more heat. Therefore, a small amount of cooling the internal mind, and should be exposed and corners to protect against cold. This process is simple, cost less and they can have enough maintenance period.

2 external heating

Apply to the following environment temperature -15 ℃ Construction and components are not Heavy engineering. By heating the air around the construction site, maintain the concrete temperature, or directly on the component heating in the concrete under normal curing temperature is. Use a stove heat, steam, warm shed, electric and infrared and other technology.

Heating stove in the small site on the application. Method is simple but not very high temperature and relatively dry, especially the stove fire and smoke accumulation of carbon dioxide released will easily fresh concrete surface carbonation, effect smooth surface, is a more primitive way.

Steam-heated steam is used the temperature and humidity curing concrete. This method allows simple and easy to control temperature uniformity, widely used in large-scale precast plant, generally difficult to do small construction site. But it requires special equipment and facilities the boiler. Heat loss of large, high cost, poor working environment.

Erection of heating house method that is shed in the field, so that components or infrastructure construction in the shed under normal temperature. Higher cost for construction of shed and heating needs, often in some key projects.

Electric heating is reinforced as the electrode, show the electric heater attached to coagulation on the surface, so that electrical energy into heat energy, to improve the concrete temperature. This method is simple and convenient, less heat loss is also easy to control. When the component when far. Electric heating to be convenient and flexible than the steam-heated, but the large power cost more.

Freezing method 3

Current production of antifreeze can be used in -10 ℃ and below the temperature of the construction. It is the use of lower freezing point, so that in the concrete with water still in the minus temperature liquid state, so that hydration can continue to improve the pore structure, to achieve the purpose of strength growth is not affected. Antifreeze divided into early strength, frost and structure of the negative temperature and so on, used antifreeze is sodium nitrite, which lowers the freezing point, and is an excellent rust inhibitor, low cost, the size of the site can be used.

4 Consolidated Law

Simultaneously using two or more arbitrary measures of the construction insulation and frost. Structure type should be based on the characteristics of the construction team and local factors to tolerate the situation to determine the energy program, has to be complemented by an early frost regenerative heat accumulation based synthesis method, have to be complemented by heat-based antifreeze, but also to the main secondary frost to heat accumulation.

5 Conclusion

The construction of measures of winter have some shortcomings, its scope is subject to certain conditions, environmental constraints, and therefore a concrete analysis of specific situations do not ask winter to construction measures to ensure the quality of Erbu winter construction waste 20% 40% of the construction season, so that increased quantities of concrete, the quality of accidents decreased. To ensure construction quality, ensure that the construction cycle, the scientific construction of the key, so that our foundation construction easier, more secure quality.