Abstract—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. Keywords—Alkali Silica Reaction, Aggregates, Moisture, Cracks, Mortar Bar Test supplementary cementitious materials. I. INTRODUCTION AND LITERATURE REVIEW SR destructive effect to hardened concrete and the premature failure of a concrete structure was first explained in the USA in the 1940 [1] Based on Stanton discovery, several deteriorated concrete structures were investigated and ASR was found responsible for the premature deterioration of hardened concrete. A notable example for ASR destructive effect was reported in Virginia where a hydroelectric plant had a severe premature deterioration for its hardened concrete [2] According to multiple research programs, the ASR reactions start when specific reactive aggregate types are mixed with cement. The white gel formed as a byproduct of the ASR expands when it reacts with moisture within the concrete. ASR components are shown in Fig. 1. ASR expansive gel, shown in Fig. 2, adds outward tensile stress on the hardened concrete. Concrete deterioration starts when the tensile stress formed overcome the restraint imposed by hardened concrete [3]. The expansive gel starts as a small accumulation of ASR byproduct. During the aging process of concrete, gel accumulations reacts with moisture infiltrating Amin Kamal Akhnoukh, Lois Zaki Kamel, and Magued Mourad Barsoum are with University of Arkansas at Little Rock, Little Rock, AR., USA (e- mail: akakhnoukh@ualr.edu, lxkamel@ualr.edu, mmbarsoum@ualr.edu). the hardened concrete to result in concrete hair cracks. Concrete hair cracks increase in number and unite to form a smaller number of larger cracks, which result in concrete degradation. Fig. 1 Components required for ASR reaction Fig. 2 ASR gel formation in hardened concrete In recent studies, more detailed explanations for the ASR were presented. During concrete mixing, the aggregate content including gravel, sand, or crushed rocks and granites is encapsulated with the cement paste, which has a high alkaline content (pH value may reach 13.5). When cement hydration process is concluded and the concrete mix hardens, the remaining (unused) mixing water and moisture dissipating through hardened concrete air voids represents a strong alkaline solution which is capable of dissolving particular siliceous particles of the aggregates resulting in the ASR gel, which expands when additional moisture is added to form the ASR damaging effect on hardened concrete. A similar damaging effect is produced when the high alkaline content of the cement paste causes chemical changes in a particular carbonate content of some aggregate types. This damaging reaction is known as alkali-carbonate reaction (ACR). Both ASR and ACR are deleterious reactions, and results in a significant premature deterioration of concrete structures. ASR and ACR damages are similar to other types of deterioration due to weathering or freeze-thaw cycles. In order to differentiate between ASR and other causes of Alkali Silica Reaction Mitigation and Prevention Measures for Arkansas Local Aggregates Amin Kamal Akhnoukh, Lois Zaki Kamel, Magued Mourad Barsoum A World Academy of Science, Engineering and Technology International Journal of Civil and Environmental Engineering Vol:10, No:2, 2016 95 International Scholarly and Scientific Research & Innovation 10(2) 2016 ISNI:0000000091950263 Open Science Index, Civil and Environmental Engineering Vol:10, No:2, 2016 publications.waset.org/10003505/pdf