Title: Effect of Carbon Dioxide on Fresh Concrete

Author(s): J. A. Kauer and R. L. Freeman

Publication: Journal Proceedings

Volume: 52

Issue: 12

Appears on pages(s): 447-454

Keywords: no keywords

DOI: 10.14359/11608

Date: 12/1/1955

Abstract:
Fresh concrete specimens were subjected to carbon dioxide immediately after molding. These specimens were then cured in various humidities and tem-peratures in CO2 atmospheres ranging from 4.5 to 18 percent for 24 to 96 hr. Tests were then made on hardness of surface, depth of carbonation, amount of carbonation on surface as compared with unexposed specimen, and compressive strengths. These tests indicated that fresh concrete exposed to CO, resulting from the use of salamanders or other heating devices which exhaust the flue gases directly into the room, have soft surfaces of various depths depending on the concentration of CO2, the temperature at which concrete is cured, and the humidities under which it is cured. The authors found that chemically produced hardeners have no appreciable effect on the surface. Grinding the surface is the only way to restore or salvage the concrete.