Now, closed cell foam board is used as the joint board of concrete highway expansion joint; Road and bridge joint waterstop; Expansion joint plates for dams, protection dams, stilling ridges, slope protection and retaining walls of hydraulic projects; Water stop joint plate at the bottom of hydropower, thermal power, engineering and water tower; Make the caulking plate of settlement joint and frame structure; Water sealing caulking board for water pool of domestic water plant and sewage treatment plant; Joint plate of airport runway; Joint plates of ports, wharves and concrete; Water passage joint plate of water tunnel and tunnel concrete; Concrete waterstop joint plate for subway and underpass. The following are the technical requirements for the construction of closed cell foam board.
1. Closed cell foamed plastic board adopts high-pressure polyethylene low foaming closed cell foamed plastic board, and the performance of materials interacting with sealant has no change.
2. Closed cell foam plastic board for buildings shall also meet the following indicators: density 120 ± 5 kg/m3, water absorption ≤ 4%, bending strength ≥ 2.5MPa, elastic modulus ≥ 1MPa, compression permanent deformation ≤ 2%, tensile strength ≥ 0.15 MPa, elongation ≥ 100%.
3. Polyethylene closed cell foam board shall be laid on the joint side of the pre poured block structure, and the joint part does not need to be overlapped, but the joint part shall be tightly connected.
In addition to strong waterproof function, closed cell foam board has other characteristics, such as cold resistance (high temperature without brittleness), high temperature resistance (high temperature without flowing), corrosion resistance (not afraid of hydrochloric acid alkali substances), unique bubble structure, high recovery rate and aging resistance. Its various characteristics promote the use of the caulking board more and more widely.
Foam plastics can be divided into low foaming, polyethylene closed cell foam board 2cm thick medium foaming and high foaming foam plastics according to the apparent density. The apparent density of the former is more than 100kg/m3, the latter is less than 50kg/m3, and the apparent density of medium foaming foam plastics is between the two. The expansion joint of airport concrete pavement shall be made of medium foaming or low foaming plastic. The physical and mechanical properties of foamed plastics depend on the properties and formula of the base polymer, the density of foam, the structure of the foam body, the shape and size of the foam cell, and the conditions for forming a 2cm thick polyethylene closed cell foam board.