A lightweight ready-mix concrete composition that contains (8 -20) volume percent cement, (11 — 50) volume percent sand, (10 — 31) volume percent prepuff particles, (9 — 40) volume percent coarse aggregate, and (10 — 22) volume percent water, where the sum of components used does not exceed (100) volume percent;. The prepuff particles have an average particle diameter of from 0.2 mm to 8 mm, a bulk density of from 0.02 g/cc to 0.64 g/cc, an aspect ratio of from 1 to 3. The slump value of the composition measured according to ASTM C 143 is from 2 to 8 inches. After the lightweight ready-mix concrete composition is set for 28 days, it has a compressive strength of at least 1400 psi as tested according to ASTM C39.