In the process of the foundation pit slope protection of shotcrete machine must pay attention to protect the concrete layer of engineering support by rockbolt and shotcrete machine, spray concrete layer after layer because of the reason of the low temperature will cause the concrete solidification, cracking and other series of bad influence, could not reach the requirements of national standards. So, let's look at the winter together shotcrete machine finish gush of foundation pit slope protection engineering:
Shotcrete machine supporting engineering in winter concrete layer maintenance methods:
1. after finishing homework, or concrete curing immediately after initial setting;
2. when fulfilling the specified form removal after curing time, it is best to its surface cladding insulation layer;
3. curing time, and the component project, cement type and presence of doped with relevant, the five kinds of common cement should be minimum of 7 days is temperature condition;
4. or mixed with admixture impermeability, resistance to the requirements of the winter project, should be minimum of 14 days and spray touch maintenance;
Priority water storage curing method, continuous curing. In 1 ~ 2 days after the concrete casting, should guarantee the concrete in a full wet state, and shall strictly observe the national standard curing age; For the board class engineering of large area, with curing agent is more practical and convenient maintenance. Black film which is formed by the curing agent can fully absorb sunlight, increase the heat absorption, inhibit the rise of temperature of the concrete. As a result, some black paint can be mixed in the curing agent. Winter casting temperature of concrete, the surface temperature of concrete to prevent storehouse send out too quickly, must be in the process of casting, to cover new pouring concrete and pouring stage heat preservation.
Warehouse surface heat preservation material generally choose heat preservation, thermal insulation used two layer 1 cm thick polyethylene insulation coil coat color plastic woven cloth, convenient for field use, insulation is generally made 1.5 m by 2.0 m. When using step casting construction, open casting requirements before each warehouse equipped with not less than 50% warehouse surface area of heat preservation was, casting is of fine ofnon-vibrating concrete cover immediately, when to uncover insulation cover new concrete is, after the vibrating cover again, until the initial set of concrete or warehouse so far, on the part of the temperature control is not very strict can until there is no strong sunshine.
DaDaiJi transmission capacity satisfy the unwinding casting, warehouse surface thermal insulation are preparation area of not less than two-thirds of the warehouse area, each casting layer vibrating area should be covered immediately, until it started cloth can uncover insulation is the upper concrete. Pouring the concrete temperature control parts of the period of don't require the use of heat preservation was in a timely manner.