Views:12 Author:Site Editor Publish Time: 2018-08-24 Origin:Site
Summer concrete construction precautions
1. Concrete mixing and transportation
(1) In the hot season or large-volume concrete construction, the cooling device can be used to cool the mixing water, and the water pipes and water tanks can be shaded and insulated.
(2) Sunscreen treatment of cement, sand and stone storage bins and material piles in the mixing station.
(3) Plan when possible to avoid pouring concrete at the highest temperature in the day.
(4) Except for adding the mixing water according to the design amount to adjust the specified slump, no additional mixing water should be added at the construction site. If it is necessary to adjust the concrete, it must be carried out by the full-time laboratory assistant under the witness of the on-site supervision engineer.
2. Concrete pouring and trimming
(1) Detect the temperature of the concrete transported to the construction site and, if necessary, require the mixing station to adjust.
(2) During the concrete construction in summer, the vibration equipment is more likely to be damaged by heat, so the spare vibrator should be prepared.
(3) All kinds of tools, equipment and materials that have contact with concrete, such as conveyors, pump pipes, concrete pouring pipes, steel bars and trolleys, etc., do not directly expose to the sun, and if necessary, sprinkle water to cool.
(4) According to the specific climatic conditions, when it is found that the concrete has the possibility of plastic shrinkage cracking, measures (such as spraying curing agent) should be taken to reduce the evaporation rate of the concrete surface.
(5) Before pouring, the concrete temperature should not exceed 32 ℃. The following measures should be taken: 1) shading or covering and cooling of aggregates and other components; 2) using cold or buried tank method or partial mixing The crushed ice was added to the water to cool the mixed water, but after the mixing was completed, the ice was completely melted.
3. Concrete conservation
(1) Arrange for full-time staff to maintain the concrete immediately after initial setting.
(2) Priority is given to the use of sprinkler maintenance methods for continuous maintenance. The concrete should be fully wetted for 1 to 2 days after concrete is poured.
(3) After the secondary lining concrete is demoulded, special personnel shall be arranged to carry out watering and moisturizing maintenance. The time of sprinkling maintenance shall not be less than 14d, and the hole section shall be strengthened and maintained, and the concrete shall be in a wet state.