Different additives (cementitious, bituminous, chemical, mechanical, biological, and proprietary blends) are routinely used to improve material properties of poor soils and aggregates ranging from highly expansive clays to more granular materials. Whereas the benefits of some of these additives are accounted for in pavement design and lifecycle processes; the benefits of Calcium Chloride (CaCl2) – a common chemical soil stabilizer is not considered.
The hygroscopic properties of CaCl2 effectively stabilizes soils through the attraction of moisture and subsequent evaporation resistance, improving compaction during construction which in turn ensures a strong and durable base material. An additional benefit of CaCl2 particularly in cold regions, is its ability to decrease the freezing point of water consequently providing enhanced resistance to frost heaving. Leaning on the successes and challenges of calcium chloride stabilized road base in Canada, this on-going Township of Woolwich study investigates the effectiveness of a 35% CaCl2 road base application for improving the short and long-term performance of an asphalt surfaced roadway and reducing the overall life-cycle costs. This study employs a monitoring program of Falling Weight Deflectometer (FWD) testing – prior to and after base stabilization, after paving and after one winter cycle – to characterize the short and long-term benefits by comparing the performance of the CaCl2 stabilized and non-stabilized (control) road base sections exhibiting good and poor drainage conditions. This paper presents the short-term findings of using CaCl2 for base stabilization. The economic benefits of incorporating CaCl2 in road base applications is evaluated, and a case for considering the benefits of a CaCl2 stabilized road base during design is further assessed.
KEY WORDS: CaCl2, Stabilization, FWD, Strength and Performance Characterization, Design Criteria, and Economic Benefits.