Concrete mixing in winter construction of aluminum formwork

  1、concrete mixing with the aggregate must be clean, and shall not contain ice and frozen blocks, as well as the material easy Donglie. In mixed with potassium, sodium ion additive, may not use the active aggregate. When conditions. Sand washing should grab the temperature at zero time, and with plastic paper, cloth cover.

  2、mixing admixture of concrete admixtures, such as powder, according to the requirements of content directly and input at the same time in the cement and cement admixture. As for the above liquid, should be used to prepare a specified concentration solution, and then according to the requirement, using the specified concentration solution prepared in aqueous solution. The solution to the container construction in marked, not confusion. Each class using a mixed solution should be additive. 

  3、when the construction period is about 0 degrees Celsius, can add Earlystrength agent in concrete, admixture shall comply with the requirements and regulations, and should be paid attention to in addition should be prepared before the experiment, to verify the relevant technical measures for a limited period; removal of concrete requirements, should also be appropriate to improve design level of concrete.

  4、the use of antifreeze in concrete, strictly prohibit the use of high alumina cement.   

  5、Strictly control the water cement ratio of concrete, the moisture from aggregate and the water in admixture solution should be deducted from mixing water.

  6、When mixing concrete with admixture, the mixing time should be 1.5 times of the mixing time at normal temperature.  

  7、the concrete mixer temperature should not be lower than 10 degrees, the mold temperature shall not be less than 5 degrees