Larry F Chappell

US Patent:

20090078161, Mar 26, 2009

Filed:

Sep 17, 2008

Appl. No.:

12/212059

Inventors:

Daniel Woolfsmith - Bridgeville PA, US
Larry Chappell - Cranberry Township PA, US
Luke Kimble - San Marcos TX, US

Assignee:

NOVA CHEMICALS INC. - Moon Township PA

International Classification:

C04B 14/38
C04B 12/00
C04B 24/26
C04B 7/02
C04B 7/32
C04B 9/00
C04B 7/14
C04B 7/12
C04B 14/10
C04B 14/22

US Classification:

106692, 106816, 524 5, 524 8, 106739, 106801, 106789, 106817, 106811, 106814, 106705

Abstract:

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./ft.