Expansion Joints and Pre-Compressed Sealants

Expansion Joints--Terms and Terminology:


Expansion Joint and Joint Sealant Glossary Index:

- Adhesion in Tension

- Blockout

- Compression Set

- Continuity of Seal

Expansion Joint

- Nosing Material

- Non-Invasive Anchoring

- Split Slab

- Sound Transmission Class (STC)

- Thermal Shock

Compression set is the permanent loss of the ability to self-expand that results after a material is subject to normal compression cycles.  Compression set is made worse by simultaneous exposure of certain materials to heat. 

Impregnated, open-cell, foam is used as the backing for precompressed sealants because it features very low compression set.

Closed-cell foams suffer on average 25% permanent compression set under movement and temperature cycles typical in construction applications.



NOTE: The definitions of terms and terminology herein are rooted in the context of use in the field of construction-related joint sealing in EMSEAL's experience.  They are provided with the intent of offering a fuller understanding of the context of their usage. Any suggestions or questions regarding interpretation are welcome and should be directed to content@emseal.com. Thank you.

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Last Modified: January 26, 2015

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