Discussion in this standard is limited to structural grade, lightweight aggregates, and structural lightweight-aggregate concrete. Structural lightweight-aggregate concrete is defined as concrete which: (a) is made with lightweight aggregates conforming to ASTM C 330, (b) has a compressive strength in excess of 2500 psi (17.2 MPa) at 28 days of age when tested in accordance with methods stated in ASTM C 330, and (c) has an equilibrium weight not exceeding 115 lb/ ft³ (1842 kg/m³) as determined by ASTM C 567. Concrete in which a portion of the lightweight aggregate is replaced by normalweight aggregate is within the scope of this standard. When normalweight fine aggregate is used, it should conform to the requirements of ASTM C 33. The use of pozzolanic and chemical admixtures is not covered in this standard.
Purpose
The purpose of this standard is to provide generally applicable methods for selecting and adjusting mixture proportions for structural lightweight concrete. These methods are also applicable to concrete containing a combination of lightweight and normalweight aggregate.