What aspects should be paid attention to when using cement mortar in four sides of the trough?
1. Selection of raw materials: in order to reduce the heat of hydration, 32.5 grade slag cement is used; considering the pumpability of concrete, reducing shrinkage, ensuring strength, improving durability and crack resistance of concrete, 5-31.5mm continuous diameter gravel is used; in order to reach the temperature of 28.5 degree of concrete mixture, deep well underground water is used to mix; UEA expansive agent and ultra-slow high-efficiency pumping agent are mixed in the concrete to compensate the shrinkage of concrete, delay the release of hydrate, reduce the temperature stress of the floor and improve the pumpability, and_grade fly ash is mixed in the concrete.
2. Pouring method: one-time pouring is required, no construction joints are left, and the anti-seepage ability of pool bottom and wall is strengthened. The concrete pouring adopts the pouring method of "inclined plane layering, progressive, thin layer pouring, natural flow, continuous construction, one time to the top" from bottom to top.
3. Vibration: Vibration time, interval between tamping points and insertion depth should be strictly controlled to avoid leakage of vibration at the junction of each pouring belt. Improve the bond strength between concrete and steel bar and increase the density.
4. Surface and bleeding water treatment: The cement mortar on the surface of the concrete after pouring is thicker. The design elevation should be scraped flat with a scraper to drive away the bleeding. Before initial setting, the surface should be repeatedly rolled and rubbed with a wooden eraser for 2-3 times to compel and collect water cracks.
5. Concrete maintenance: For example, in autumn, the temperature difference between noon and night is large. In order to ensure the quality of concrete construction and control the occurrence of temperature cracks, water storage maintenance is adopted. Before storing water, a layer of plastic film and a layer of straw bags should be first used for temporary moisture conservation.