Technical Questions

ACI Committees, Membership, and Staff have answered common questions on a variety of concrete related topics.

Hardening of hydraulic cement

Q. What causes hardening of hydraulic cement (or concrete)?


A. When hydraulic cement is mixed with water to form a paste, the phases of the cement react with the water (hydration) to form a slowly developing cementitious structure that adheres to and binds together the fine-and coarse-aggregate particles to form hardened concrete. The most abundant hydration product is calcium-silicate hydrate. As long as moisture and unhydrated cement particles are present, the hydration products continue to form, increasing the strength of the concrete.


References: SP-1(02); E3-13

Topics in Concrete: Cementitious Material; Materials; Pozzolan

Other Sources for Answers

Search other resources on the ACI website for answers to technical questions