We all know that the temperature in winter is relatively low, especially at night, the temperature is below -10 degrees. If you choose to carry out road construction in winter, the problem of permeable concrete freezing will occur, increasing the difficulty of construction. The construction temperature of permeable concrete should be between 15 ℃ -25 ℃, the temperature in summer is higher than 35 ℃, and the temperature in winter is lower than 5 ℃. It is not suitable to construct. If there is a need to perform permeable concrete construction in winter, what are the issues that need attention? ?
Pay attention to the following issues in the construction of permeable concrete in winter:
1. The proportion of materials must be strictly adhered to. The proportion of reinforcing agents, aggregates and powders must be in accordance with the standards, and the proportion of additives must be adjusted according to the site's climate temperature to shorten the curing time of the permeable layer.
2. Pay attention to the maintenance during the construction process and after the construction is completed. You can arrange personnel to be on site or set up a no-go reminder. The permeable layer solidifies slowly in winter. It is recommended not to walk around within 3 days.
3. After the construction of the permeable concrete is completed, the construction pavement should be completely covered with plastic film. The normal edge part should be covered by 20 cm more, the more rigid the better. Since the temperature is relatively low in winter, it is recommended to cover it with a layer of geotextile.
4. If the foundation is a water stable layer or a cement pavement, it must be a drainage pipe network or find a way to drain rainwater to the designated place. The most worrying thing is that the winter freezes, because the rain can't be effectively discharged, the effects of thermal expansion and contraction will cause the phenomenon of emptying. The best solution is to use graded crushed stones on the bottom layer, and rainwater can penetrate the soil through the graded crushed stones, so that no hollowing occurs.
5. If the temperature throughout the day is lower than 5 ℃, do not carry out large-scale construction, and wait for the weather temperature to rise before laying.
6. Due to the large number of construction and construction projects nowadays, many roads are backfilled and the pavement is not solid. If water-pervious roads are used in this case, the pavement must be compacted with a compaction degree of> 93% and graded crushing placed on After the stone is compacted, a permeable layer can be laid on the graded crushed stone.
If you need to carry out permeable concrete construction in winter, you must pay attention to the above points, so as to ensure that the probability of pavement quality damage is small. Permeable concrete is also afraid of cold in winter, and frozen blocks or other impurities in aggregate should be prevented during winter construction. And according to the characteristics of the project added antifreeze, early strength agent and so on. Properly extend the mixing time of the permeable concrete. The permeable concrete should be covered with heat-insulating material when the transportation distance is long. After the construction of the permeable concrete floor, the heat-resistant material should be covered with anti-freezing measures according to the temperature. phenomenon.
