Characterization of Hydrated Cement Treated Crushed Rock Base (HCTCRB) as a Road Base Material in Western Australia P. Jitsangiam, 1 H. R. Nikraz 2 , and K.Siripun 3 1 Lecturer, Department of Civil Engineering, Curtin University of Technology, P.O. Box U1987, Perth, WA, Australia 9845; PH (61) 8 9266-4527; FAX (61) 9266-2681; e-mail: p.jitsangiam@curtin.edu.au ; 2 Professor, Department of Civil Engineering, Curtin University of Technology, P.O. Box U1987, Perth, WA, Australia 9845; PH (61) 8 9266-7609; FAX (61) 9266-2681; e-mail: h.nikraz@curtin.edu.au ; 3 PhD candidate, Department of Civil Engineering, Curtin University of Technology, P.O. Box U1987, Perth, WA, Australia 9845; e-mail: komsun.siripun@postgrad.curtin.edu.au ABSTRACT Hydrated Cement Treated Crushed Rock Base (HCTCRB) is widely used as a base course material for Western Australian roads. HCTCRB has been designed and used based on an empirical approach and practical experience, respectively, but those are not capable of explaining behavior of HCTCRB. Presently, a mechanistic approach becomes more reliable in pavement design and analysis and behavior of pavements can be more understood. Consequently, characterization of HCTCRB following the mechanistic approach is necessary. This study aimed to analyze the results of laboratory testing so as to assess the mechanical characteristics of HCTCRB. Conventional triaxial tests and repeated load triaxial tests (RLT tests) were performed. Factors, which would affect the performance of HCTCRB such as hydration periods and the amount of water added, were also investigated. INTRODUCTION Crushed rock with the addition of 2% General Purpose (GP) Portland Cement, known as Hydrated Cemented Treated Crushed Rock Base (HCTCRB), is commonly used as a base course material for Western Australian roads. Understanding HCTCRB with respect to shear strength, resilient modulus, and permanent characteristics is important because if these characteristics are well- understood, pavement analysis and design can be done more precisely than in the past. In practice, a large volume of HCTCRB is usually produced daily and then, kept in stockpiles waiting for an appropriate hydration period. It is difficult to maintain the same hydration period and to fix the appropriate amount of water added to produce HCTCRB. Furthermore, there are some doubts about the effect of hydration periods and amount of water added on the material’s performance. Both factors need to be investigated to obtain more effective use of HCTCRB. link to the published version; http://dx.doi.org/10.1061/41043(350)1