Astm C 920 -

ASTM C920 is the go-to specification for architects, specifiers, and engineers because it . A sealant that meets C920 Class 50 has been proven to survive thousands of simulated movement cycles without losing adhesion or cohesion.

: Ability to maintain adhesion and cohesion during repeated expansion and contraction. Adhesion-in-Peel : Strength of the bond to the substrate.

| Spec Code | Translation | Common Application | | :--- | :--- | :--- | | | Stretchy, Non-Sag, No Traffic | Standard vertical wall expansion joints, window perimeters. | | Class 25, Grade P, Use T | Stretchy, Self-Leveling, Traffic | Parking garage floor joints, sidewalks. | | Class 12.5 | Low Movement | Small gaps, static joints (less common in modern high-performance specs). | | Type M | Multi-Component | Large projects (like airports/malls) where fast cure and high durability are needed. | | Type S | Single-Component | General construction, smaller jobs, easy repair work. | astm c 920

: Testing for sag or flow (for Grade NS).

The primary goal of the standard is to provide a comprehensive framework for classifying sealants so that architects and contractors can select the right product for specific environmental and structural demands. ASTM C920 is the go-to specification for architects,

Class is perhaps the most critical metric, indicating the percentage of joint movement a sealant can handle relative to its original width. ASTM C920 Joint Sealant: Type, Grade, Class & Use

Detailed technical documents and test reports can be found through resources like Euclid Chemical , Soudal , and Scribd . Adhesion-in-Peel : Strength of the bond to the substrate

Consists of two or more parts that must be mixed before application to initiate curing. Grade: Flow Characteristics