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Cement is the core ingredient in concrete, the most widely used building material in the world. It plays an integral role in infrastructure such as buildings, bridges and roadways by providing strength, durability and resiliency. NIST’s well-characterized cement reference samples ensure the integrity of structures around the globe.

artsy photo of a concrete wall at Bronx Comunity College
Credit: By Carlyncarlyn [CC BY-SA 4.0 (], from Wikimedia Commons

The strength and reliability of buildings, bridges and roadways can be traced to the performance of cement—a fine powder of limestone, clay, sand and gypsum. When mixed with water, it creates a paste that can bind sand and rock together and harden into concrete. Manufacturers strive for uniformly reliable cement, relying on standard test methods developed and validated by the American Society for Testing and Materials (ASTM) International.

NIST offers more than 20 types of cement standard reference materials (SRM®) that support these standard test methods to ensure quality cement products.

To support the industry adoption of new sustainability practices, NIST recently developed two new cement SRMs: one that contains slag, a byproduct of iron production, and one that contains fly ash, a byproduct of burning coal for power generation. Previously considered waste byproducts, recent research indicates that slag and fly ash can be used to create improved cement that requires less water to mix into concrete, sets faster, flows more easily through pumps, and creates a stronger and less permeable concrete. The new fly ash and slag cement SRMs are examples of how NIST continues to respond to the evolving needs of the $1 trillion global cement industry.