Quality Assurance and Quality Control Requirements for Lime and Cement Subgrade Stabilization

摘要

Presented herein are the results of a pilot in-situ and laboratory testing program aimed at identifying the key quality assurance and quality control measures for proper construction of lime and cement subgrade stabilization. Dynamic cone penetrometer (DCP) and Clegg impact hammer (CIH) tests were performed on the stabilized subgrade at various times upon completion of stabilization. In addition, undisturbed samples were taken and subjected to unconfined compressive strength (UCS) and resilient modulus (M_R) tests following a laboratory curing process. The test results illustrate the importance of proper mixing and compaction of the subgrade on the strength gain with time—the higher the compaction the higher the strength gain. This work also provided insights into the advantages and limitations of various field and laboratory testing techniques and offered a means for verifying target M_R and UCS values in the field using Clegg hammer and dynamic cone testing as well as in the laboratory using retrieved stabilized subgrade samples.