Rationale

Working Group to revise definition of Fiber as it applies to fiber-reinforced cement in Standard ASTM C1154 ________________________________________ Establish a working group to review and revise the current definition of fiber as it applies to fiber-reinforced cement within ASTM C1154 Specifically, the proposal recommends modifying the existing aspect ratio from: fiber size ratio of 1:10 to: fiber size ratio of 1:5 fiber, n—in fiber-reinforced cement, any material in a form such that it has an aspect ratio of at least 5 and a typical transverse dimension less than 2 mm. ________________________________________ The current language defining fiber, n—in fiber-reinforced cement, was developed during a period when the market was dominated by traditional fiber geometries and manufacturing technologies. Since that time, substantial advancements have occurred in: • fiber engineering, • composite material science, • manufacturing processes, • product performance testing, and • exterior cladding system design. Established fiber-reinforced cement products currently in the market use reinforcing fibers with aspect ratios closer to 1:5. These products have a long history of proven performance and have demonstrated compliance with durability, strength, weather resistance, dimensional stability, and service-life expectations.