| 摘要 |
<p>A method of reducing plastic shrinkage cracking in concrete compositions that includes a) combining 3 -40 volume percent cement, 5 - 50 volume percent fine aggregate, 5 - 50 volume percent coarse aggregate, and 10 - 22 volume percent water to form a concrete mixture; b) during or after (a), adding 1.5 - 40 volume percent of prepuff particles to the concrete mixture to form a concrete composition; c) placing the concrete composition in a form; and d) allowing the concrete to set and harden to form a hardened concrete article substantially free of plastic shrinkage cracking. 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 concrete composition has a density of from about 40 to about 135 lb./ft3.</p> |
