Alkali Silica Reaction Mitigation and Prevention Measures for Arkansas Local Aggregates

The objective of this research is to mitigate and prevent
the alkali silica reactivity (ASR) in highway construction projects.
ASR is a deleterious reaction initiated when the silica content of the
aggregate reacts with alkali hydroxides in cement in the presence of
relatively high moisture content. The ASR results in the formation of
an expansive white colored gel-like material which forms the
destructive tensile stresses inside hardened concrete. In this research, different types of local aggregates available in the
State of Arkansas were mixed and mortar bars were poured according
to the ASTM specifications. Mortar bars expansion was measured
versus time and aggregates with potential ASR problems were
detected. Different types of supplementary cementitious materials
(SCMs) were used in remixing mortar bars with highly reactive
aggregates. Length changes for remixed bars proved that different
types of SCMs can be successfully used in reducing the expansive
effect of ASR. SCMs percentage by weight is highly dependent on
the SCM type. The result of this study will help avoiding future
losses due to ASR cracking in construction project and reduce the
maintenance, repair, and replacement budgets required for highways
network.

Authors:

• Amin Kamal Akhnoukh
• Lois Zaki Kamel
• Magued Mourad Barsoum

Keywords:

• Alkali Silica Reaction
• Aggregates
• Moisture
• Cracks
• Mortar Bar Test supplementary cementitious materials.

References:

[1] Stanton, T.E., “Expansion of Concrete through Reaction between
Cement and Aggregates,” Proceedings, American Society of Civil
Engineers, Vol. 66, New York, 1940, pp. 1781-1811
[2] Stark, D., “Handbook for the Identification of Alkali-Silica Reactivity in
Highway Structures,” SHRP-C/FR-91-101, TRB National Research
Council, 49p., 1991.
[3] Kammer, H. A. and Carlson, R. W. (1941). Investigation of causes of
delayed expansions of concrete in buck hydroelectric plant. Journal of
the American Concrete Institute, 3 7, 665-671.
[4] Fournier, B., Berube, M., Folliard, K, and Thomas, M., “Report on the
diagnosis Prognosis and Mitigation of Alkali-Silica Reaction (ASR) in
Transportation Structure, FHWA-HIF-09-004, 2010
[5] Oberholster, R.E., and Davies, G., “An Accelerated Method for Testing
the Potential Alkali Reactivity of Siliceous Aggregates,” Cement and
Concrete Research, Vol. 16, 1986, pages 181-189