• The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: Effect of Stress on Gas Permeability in Concrete

Author(s): Takafumi Sugiyama, Theodore W. Bremner, and Thomas A. Holm

Publication: Materials Journal

Volume: 93

Issue: 5

Appears on pages(s): 443-450

Keywords: compression tests; lightweight concretes; microcracking; per-meability; saturation; stresses.

Date: 9/1/1996

The effect of compressive stress on the permeability of concrete was experi-mentally investigated using nitrogen gas as the flowing substance. A uniaxial compressive load was applied to a cylindrical hollow concrete specimen and increased by steps until failure, while a constant nitrogen gas pressure was maintained between the walls of the hollow cylinder and the volumetric gas flow rate was measured in a steady state. Gas permeability was then calculated and compared at increasing stress levels. Structural lightweight concrete with water-cement ratios of 0.4 and 0.6 was compared with normal- weight concrete with equal water-cement ratios and at similar stress levels. The stress level at which gas permeability increased significantly (significant stress level) was 76 to 79 percent of the ultimate strength for normal-weight concrete, whereas it was 82 to 89 percent of ultimate strength for the lightweight concrete. Structural lightweight concrete had both a higher significant stress level and a higher stress level at which dila-tion due to microcracking was noted (critical stress level) compared to nor-mal- weight concrete. Furthermore, normal-weight and structural lightweight concrete with different degrees of water saturation were tested. A higher degree of saturation resulted in a higher significant stress level.


Electronic Materials Journal


Please enter this 5 digit unlock code on the web page.