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Home > Publications > International Concrete Abstracts Portal
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.
Showing 1-5 of 12 Abstracts search results
Document:
SP108-11
Date:
August 1, 1988
Author(s):
D. Whiting
Publication:
Symposium Papers
Volume:
108
Abstract:
Study of permeability was made using six concrete mixtures ranging in water-to-cementitious material (w-c) ratio from 0.26 to 0.75. Concrete specimens were tested for permeability to water and air, permeability to chloride ions (rapid and long-term), volume of permeable voids, and porosity. Results confirm that permeability is a direct function of w-c ratio. The addition of silica fume results in even greater decreases in permeability than would be anticipated based solely on w-c ratio. A period of initial moist curing of at least seven days is essential for achieving low permeability. Results also indicate that rapid test procedures offer a reasonable alternative to more lengthy and complex conventional permeability tests.
DOI:
10.14359/2186
SP108-07
B. Mobasher and T. M. Mitchell
The new rapid chloride permeability test, in which chloride ions are driven into concrete samples electrically over a 6-hr period, is becoming widely used and has been accepted as an American Association of State and Highway Transportation Officials (AASHTO) standard, T277. This paper summarizes the results of an extensive series of laboratory tests with the new method. Results of an interlaboratory test program provide single-operator and multilaboratory coefficients of variation suitable for use in a precision statement in the standard versions of the method. Several possible revisions to the AASHTO standard procedure are examined, but further study is necessary before any can be accepted. Test results on specimens with diameters other than the standard 3.75 in. (95 mm) called for in T277 are found to be easily adjusted to allow comparisons with standard size specimens. Several fundamental properties of concrete, namely, water-cement ratio, coarse aggregate type and gradation, and air content, are shown to affect chloride permeability.
10.14359/3621
SP108-08
D. J. Janssen
Equipment and procedures for measuring actual permeability of portland cement concrete are presented. The equipment is built from readily available parts and materials and requires only standard laboratory air pressure and vacuum sources. The sample size used is 3 in. (7.5 cm) diameter x 3-1/8 in. (8 cm) long, but other sample sizes could be used. Typical measurements are presented to show repeatability and time required for permeability testing. The equipment has been used for permeabilities as low as 1 x 10-11 cm/sec. Concrete with lower permeability would require equipment modifications and/or longer measurement times.
10.14359/3633
SP108-10
A. Bisaillon and V. M. Malhotra
Paper describes the modifications made to a previously developed CANMET test method to measure the permeability of concrete and discusses test results to determine the reproducibility of the test method. Briefly, the test method consists of measuring the uniaxial water flow through cylinders (125 mm high with a diameter of 150 mm) under a pressure of 3.5 MPa. A large number of concrete specimens with water-cement ratios of 0.65 and 0.80 were tested. A limited number of test specimens having w/c of 0.22 and 0.27 were also tested. Test results show that the within-batch variation for the test method is high, and this is probably due to the heterogenous nature of the concrete. For concrete with w/c of 0.22 and 0.27, there was no outflow of water, and this technique in the present form may not be suitable for measuring the permeability of very high strength concrete.
10.14359/3671
SP108-06
K. Schonlin and H.K. Hilsorf
For the determination of the permeability on concrete discs, a rapid test method has been developed. No special devices are required to fix the test apparatus to the specimen. Air permeability of the concrete can be measured within a period of about 15 min. Laboratory experiments show a close correlation between the measured permeability coefficient and the duration of curing, type of cement, w/c ratio and the content of fly ash.
10.14359/3608
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