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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:
SP108-06
Date:
August 1, 1988
Author(s):
K. Schonlin and H.K. Hilsorf
Publication:
Symposium Papers
Volume:
108
Abstract:
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.
DOI:
10.14359/3608
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
SP108-09
B. R. Sullivan
A testing system which can accommodate up to seven samples simultaneously with computer-controlled data acquisition, analysis, and reporting is described. The system consists of seven core holders of the Hassler type which can handle cylindrical samples ranging from 1-1/2 to 4 in. in diameter and from 4 to 11 in. in length. Confining and driving pressures can be independently varied up to 4000 psi. The test medium can be either liquid or gas including brine, since all tubing and containers are stainless steel. Flow is determined by pressure increase in a collector tank for gas and change in liquid level in a pipette column for liquid. Four pressure transducers per core holder are used to monitor all pressure levels during a test. A computer-based data acquisition system is used to scan up to seven tests simultaneously and record all data on a disc. Upon termination of a test, flow and permeability are computed and plotted against time and a report is printed for the test. The data are saved permanently on the disk and a backup copy is transferred to a floppy disk for safe storage. Sample preparation, sealing, and testing procedures are explained. Data analysis and typical results are presented on salt cores and concrete samples.
10.14359/3660
SP108-03
C. Ozyildirim and W. Halstead
The effects of two pozzolanic admixtures, fly ash and silica fume, and a ground-granulated blast furnace slag on the chloride ion intrusion of concretes prepared with low water-to-cementitious material ratios (0.35 to 0.45) were investigated. Results of the rapid permeability test (AASHTO T 277) showed that the resistance of concrete to the penetration of chloride ions increases significantly as the water-to-cementitious material ratio is decreased for the same proportions of solid ingredients. Most concretes with pozzolans or slag exhibited higher resistance to chloride ion penetration than the control concretes containing portland cement as the cementitious material. Results of the 90-day ponding test (similar to AASHTO T 259), which was conducted with 0.40 w/c concretes only, indicated minimal chloride content at depths below 3/4 in. (19 mm) for all the test concretes. Strength values for all concretes made with the pozzolans and slag at 90 days were in excess of 5000 psi (34.5 MPa), which is satisfactory.
10.14359/2158
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