Early Age Thermal Measurements of Soil-Cement Mixtures for Quality Control during Paving

Abstract

Abstract Cementitiously stabilized soil (i.e., soil-cement) is popular among some state departments of transportation (DOTs) for subbase and base pavement layers, particularly, states with limited supplies of quality aggregates. When constructed properly, soil-cement has proven to be a well-performing and economically beneficial product for multiple DOTs; however, there is still a growing need to better characterize soil-cement properties in the laboratory and especially during construction. This need could partly be met with thermal profile measurements of hydrating soil-cement mixtures. The overall purpose of this article is to investigate the potential use of thermal measurements as a quality control tool for compacted soil-cement mixtures used in pavement layers. A compaction device, referred to as the Plastic Mold (PM) device, was central to the approach presented in this article to perform thermal measurement and unconfined compressive strength (UCS) testing on the same specimen. Based on data presented in this article, thermal profile measurements of soil-cement mixtures are feasible and have some merit as a quality control tool. Variability analysis under laboratory conditions showed measured thermal profile results were less variable or equally as variable as UCS measurements. Under field conditions, thermal profile testing was observed to be sensitive to initial material temperature, thermal device insulation, and surrounding environment temperatures. Implementation of thermal measurements into soil-cement quality control seems to be best suited as supporting information only for cases in which UCS measured by the PM device needs more explanation.