International Concrete Abstracts Portal

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


Document: 

SP108-07

Date: 

August 1, 1988

Author(s):

B. Mobasher and T. M. Mitchell

Publication:

Symposium Papers

Volume:

108

Abstract:

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.

DOI:

10.14359/3621


Document: 

SP108-08

Date: 

August 1, 1988

Author(s):

D. J. Janssen

Publication:

Symposium Papers

Volume:

108

Abstract:

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.

DOI:

10.14359/3633


Document: 

SP108-09

Date: 

August 1, 1988

Author(s):

B. R. Sullivan

Publication:

Symposium Papers

Volume:

108

Abstract:

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.

DOI:

10.14359/3660


Document: 

SP108-04

Date: 

August 1, 1988

Author(s):

D. Perraton, P.C. Aiticin, and D. Vezina

Publication:

Symposium Papers

Volume:

108

Abstract:

Water, chloride-ion, and air permeability of two series of silica fume and non-silica fume concretes having water-cementitious ratios of 0.4 and 0.5 were studied as well as that of a 0.24 water-cementitious ratio silica fume concrete. Silica fume dosage varied from 5 to 20 percent by weight of cement. The water permeability of concrete samples having water-cementitious ratios lower than 0.5 is so low that they can be considered impervious whether they contain silica fume or not. The chloride-ion impermeability provided by silica fume rivals that of latex for water-cementitious ratios of 0.4 to 0.5 and polymer-impregnated concrete with a 0.24 w/c ratio. The two drying methods used in this research yielded a positive correlation between silica fume dosage and air permeability. Equal variations were observed for values of up to 10 percent, whereas at twenty percent, the increase was markedly sharper. The characterization of concrete permeability is not as simple as it appears. Sample preparation and fluid type can significantly affect the interpretation of the effect of an admixture such as silica fume.

DOI:

10.14359/2167


123

Results Per Page 




Edit Module Settings to define Page Content Reviewer