Technical Questions

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

The effect of aggregate strength on concrete strength

Q. How does the strength of the aggregate particles affect the strength of the concrete?


A. The strength of concrete is affected very little by the strength of aggregate particles, except when aggregates are

of lower strength than the strength of the matrix. Just because an aggregate is low density does not mean it is low strength. Some expanded-clay, low-density aggregates are quite strong and have been used to produce concrete with strength in excess of 70 MPa (10,000 psi).


References: SP-1(02); E-1(16); ACI 221R-96; ACI 214R-11; ACI 213R-14; ACI 363R-10; ASTM C33

Topics in Concrete: Aggregate; Concrete Fundamentals; Materials; High Performance Concrete

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