Improving Long-Term Performance of Cement-Treated Aggregate Base Materials

摘要

Recent research projects at the Texas Transportation Institute (TTI) have focused on methods of improving the long-term performance of cement-treated bases. These methods primarily address proper selection of optimum cement contents through laboratory testing and innovative construction techniques in the field. Researchers performed a literature review to document the development of current specifications for selecting cement contents for stabilizing aggregate base materials. They also investigated the availability of additional tests for assessing other properties of cement-stabilized aggregates that could be used to more accurately predict field performance and more appropriately select optimum cement contents. Construction methods for mitigating shrinkage cracking were also identified in the literature search. Based on this review, researchers designed a laboratory test sequence to evaluate the consequences of reduced cement contents on the performance of two aggregates, limestone and recycled concrete, typically used in the Texas Department of Transportation (TxDOT) Houston District. Researchers determined the mineralogy of each material, and the performance of the aggregates in their untreated conditions was documented to study the impacts of three levels of cement stabilization.