Precautions for bonding expansion joint sealant


(1) The sealant should be selected to have poor bonding performance with the concrete component substrate or corresponding supporting accessories.

(2) The bonding surface of prefabricated components should be cleaned to ensure good adhesion between the sealant and the substrate.
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  a. Use the matching primer according to the product requirements, apply adhesive during the effective period of the primer, and strengthen the interface bonding for a more firm bond.

  b. Set the backing material or backing material, press it tightly, and ensure sufficient support from the back of the adhesive to ensure good contact between the sealant and the interface.

  c. Ensure that the bonding surface of the substrate is free from moisture, impurities such as isolation agents, dust, and particles, and that the base surface is repaired and leveled to ensure good interface bonding.

(3) The adhesive application process for prefabricated component joints should be standardized, and this construction should be embedded and compacted tightly; The climate and environmental conditions for adhesive construction should meet the requirements to make the bonding more firm.
 
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  Instructions for using expansion joint sealant

(1) Choose sealant with appropriate material and performance. Before applying sealant, several types of sealant materials can be selected for compatibility testing.


(2) Two component sealant should use matching primer, while single component sealant is recommended to use primer. The gluing operation should be carried out 30 minutes after the bottom coat is applied and before the surface drying time. The surface drying time of the bottom coat liquid is generally 8-10 hours, and the surface of the bottom coat liquid must be free of floating ash and floating slag. Non stick backing materials, such as PE rods, should be used to prevent three sided bonding of colloids. The density of PE rod material is required to be no less than 37kg/m³, The diameter size shall not be less than 1.5 times the width of the seam. When applying adhesive to the joint, it should be ensured that the base material of the joint bonding surface is in a dry state, and the surface should be free of impurities such as floating ash and floating slag that affect the bonding.

During construction, the sealant should be pressed and scraped flat to ensure sufficient bonding between the sealant and the substrate. The temperature of the adhesive working environment should not be lower than 5 ℃ and should not exceed 35 ℃. The experiment should be conducted after the colloid has completely solidified. For two-component adhesives, it is generally not less than 1 day, and for single component adhesives, it is generally not less than 7 days.
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