Civil Engineering Reference
In-Depth Information
in plastic jugs or bags. Powdered admixtures, such as cer-
tain plasticizers, or a barrel of admixture may be stored at
the project site.
Dispenser tanks at concrete plants should be properly
labeled for specific admixtures to avoid contamination
and avoid dosing the wrong admixture. Most liquid
chemical admixtures should not be allowed to freeze;
therefore, they should be stored in heated environments.
Consult the admixture manufacturer for proper storage
temperatures. Powdered admixtures are usually less
sensitive to temperature restrictions, but may be sensitive
to moisture.
Liquid chemical admixtures are usually dispensed
individually in the batch water by volumetric means (Fig.
6-20). Liquid and powdered admixtures can be measured
by mass, but powdered admixtures should not be meas-
ured by volume. Care should be taken to not combine
certain admixtures prior to their dispensing into the batch
as some combinations may neutralize the desired effect of
the admixtures. Consult the admixture manufacturer con-
cerning compatible admixture combinations or perform
laboratory tests to document performance.
REFERENCES
AASHTO, “Portland Cement Concrete Resistant to
Excessive Expansion Caused by Alkali-Silica Reaction,”
Section 56X,
Guide Specification For Highway Construction,
http://leadstates.tamu.edu/ASR/library/gspec.stm
, Ameri-
can Association of State Highway and Transportation
Officials, Washington, D.C., 2001.
Abrams, Duff A.,
Calcium Chloride as an Admixture in
Concrete,
Bulletin 13 (PCA
LS013
), Structural Materials
Research Laboratory, Lewis Institute, Chicago,
http://
www.portcement.org/pdf_files/LS013.pdf
, 1924.
ACI Committee 212,
Chemical Admixtures for Concrete,
ACI
212.3R-91, American Concrete Institute, Farmington Hills,
Michigan, 1991.
ACI Committee 212,
Guide for the Use of High-Range Water-
Reducing Admixtures (Superplasticizers) in Concrete,
ACI
212.4R-93 (Reapproved 1998), American Concrete Insti-
tute, Farmington Hills, Michigan, 1998.
ACI Committee 222,
Corrosion of Metals in Concrete,
ACI
222R-96, American Concrete Institute, Farmington Hills,
Michigan, 1996.
ACI Committee 318,
Building Code Requirements for
Structural Concrete and Commentary,
ACI 318-02, American
Concrete Institute, Farmington Hills, Michigan, 2002.
ACI E4,
Chemical and Air-Entraining Admixtures for Concrete,
ACI Education Bulletin No. E4-96, American Concrete
Institute, Farmington Hills, Michigan, 1999, 16 pages.
Aldred, James M., “HPI Concrete,”
Concrete International,
American Concrete Institute, Farmington Hills, Michigan,
November 1988.
Berke, N. S., and Weil, T. G., “World Wide Review of
Corrosion Inhibitors in Concrete,”
Advances in Concrete
Technology
, CANMET, Ottawa, 1994, pages 891 to 914.
Chou, Gee Kin, “Cathodic Protection: An Emerging
Solution to the Rebar Corrosion Problem,”
Concrete Con-
struction,
Addison, Illinois, June 1984.
Fig. 6-20. Liquid admixture dispenser at a ready mix plant
provides accurate volumetric measurement of admixtures.
(44220)
Gajda, John,
Development of a Cement to Inhibit Alkali-Silica
Reactivity,
Research and Development Bulletin
RD115
,
Portland Cement Association, 1996, 58 pages.
Gaynor, Richard D., “Calculating Chloride Percentages,”
Concrete Technology Today,
PL983
, Portland Cement Associ-
ation,
http://www.portcement.org/pdf_files/PL983.pdf
,
1998, pages 4 to 5.
Gebler, S. H.,
The Effects of High-Range Water Reducers on the
Properties of Freshly Mixed and Hardened Flowing Concrete,
Research and Development Bulletin
RD081
, Portland
Cement Association,
http://www.portcement.org/pdf_
files/RD081.pdf
, 1982.
