When the length or depth of the cold storage is greater than 50m, an expansion joint should be installed. There are many large-scale cold storages. Since there is no expansion joint on the floor of the cold storage, the ground has a large area of cracks, which will cause the floor of the cold storage to be unsightly. If it is not repaired in time, the cold storage will be damaged. The air barrier is torn, and the cold storage insulation material is damp, which reduces the performance of thermal insulation and ultimately affects the service life of the cold storage. Problems such as deformation seams should not be underestimated. The following conclusions are made for these problems:
1. The deformation joints of cold storage buildings can be divided into three types: expansion joints, settlement joints and seismic joints. When the cold storage building is too long, due to the temperature change, the cold storage structure will be damaged due to thermal expansion and contraction of the material, resulting in cracks in the outer wall and roof, affecting the use, or tearing the air barrier to make heat insulation The material deteriorates with moisture, reducing its thermal insulation properties. Therefore, according to the building structure and different materials, expansion joints should be set within a certain distance, such as one set at 55m for cast-in-place frame structure, one set at 75m for prefabricated frame structure, and one expansion joint when the length and depth of the cold storage is greater than 50m.
⒈ Settlement joint
When the height difference between adjacent buildings is large, or due to different structural types, the load is very different, and the foundation properties are significantly different, in order to avoid damage to the building due to uneven subsidence, it is necessary to set settlement joints. As far as the refrigeration engineering of cold storage is concerned, settlement joints should be set in the following parts.
(1) The junction between the cold storage and the hall with a large difference in load.
(2) The junction of different structural (or foundation) types
(3) Where the soil quality of the foundation is significantly different
(4) The junction of a multi-storey cold storage building with a large height difference and a single-storey building (freezing room, ice storage, computer room, etc.).
The method of settlement joint is generally to cut off from the roof to the foundation. Its width should be valued according to the current relevant national standards, generally 20mm~30mm, and generally do not fill any material in the joint. If the settlement joint is consistent with the expansion joint, it can also be used as an expansion joint.
⒉Seismic joint
In the ground vibration area, due to the different structures and stiffnesses of the main cold storage and the auxiliary buildings, their seismic performance is different, so the cold storage and hall of the frame structure should not be connected with the production or living room of the mixed structure. Seismic joints separate them. The width of the anti-seismic joints shall not be less than 50mm under any circumstances, and the joints should be left empty. When the height of the building exceeds 10m, the joint width will increase by 20mm for every 5m increase.
2. For the insulation treatment of the cold storage floor, the cold storage insulation prefabricated board or extruded plastic board can generally be used, but the load-bearing capacity of the ground is limited, and it is only suitable for small cold storage. The ground of large cold storage can use concrete leveling layer + sbs waterproof layer + extruded plastic board insulation + reinforced concrete + curing agent (emery), this method bears better load and is favored by many users. The practice of the cold storage floor is generally designed according to the user’s own usage and requirements, so as to reduce the unnecessary initial investment of the user.
Floor insulation for small, medium and large cold storages:
Floor Insulation of Small Cold Storage
The storage structure of a small cold storage is usually called a hexahedron, that is, the top surface, walls and ground are all made of color steel plate/stainless steel with suitable thickness of insulation materials such as polyurethane, because the loading and unloading of small cold storage is often manual handling instead of forklifts. Of course, if the height of the warehouse is high and forklifts need to be loaded and unloaded, it is not recommended to use insulation boards for ground insulation, but the ground needs to be insulated separately like the ground insulation method of medium-sized cold storage.
Floor insulation of medium-sized cold storage
The storage structure of the medium-sized cold storage is what we often call the pentahedron, that is, the top surface and the wall are made of color steel plate/stainless steel with suitable thickness of insulation materials such as polyurethane, and the ground needs to be insulated separately. At present, the common operation method on the market is: using XPS extruded board to lay the ground, laying moisture-proof and vapor-proof SPS material on the top and bottom of the extruded board, and then pouring concrete or reinforced concrete.
Floor insulation of large cold storage
We can think that the ground insulation of medium-sized cold storage is more complicated than that of small cold storage, and the ground insulation operation of large-scale cold storage with larger storage area is more complicated. The common operation method is: first laying ventilation pipes to prevent the ground freezing drum from breaking, then laying XPS extruded boards (staggered laying is required when laying extruded boards), and then laying moisture-proof vapor barrier layers on the upper and lower sides of the extruded boards, and then pouring steel bars Concrete (generally at least 15cm thick), and finally make emery floor or epoxy floor according to requirements. Among them, the XPS extruded board to be laid is also laid with the appropriate thickness according to the storage temperature. For example, a low-temperature cold storage needs to lay a 150-200mm thick XPS extruded board, while a high-temperature cold storage can lay a 100-150 mm thick XPS extruded board. plastic board.
Post time: Jan-10-2022