Evaluating Impact Resonance Testing as a Tool for Predicting Hydraulic Conductivity and Strength Changes in Cement-Stabilized Soils

Abstract

In this paper the impact resonance (IR) test method is used as a nondestructive tool to examine the curing progression, freeze/thaw (f/t) resistance, and healing potential of cement-stabilized soils. Resonant frequency (RF) measurements on specimens moist cured for up to 241 days indicate that the main portion of the hydration process is completed after about 60 days. Results of RF measurements on immature (i.e., cured for 16 days) and mature (i.e., cured for over 110 days) specimens exposed to 12 cycles of f/t indicate that the initial f/t exposure had a significant effect on the degradation of the structure. After the initial f/t cycle, some specimens exhibited continued reductions in RF values to as low as 10% of the initial measurements, while several specimens showed signs of recovery leading to minor increases in the RF values. Changes in RF values are compared with the hydraulic conductivity changes measured on the same specimens reported in a previous publication by the authors. Based on the results, a prescreening scheme is proposed that can significantly reduce the time required for f/t studies of cement-stabilized soils. Also, RF measurements after 120 days of a post-exposure healing period show a significant potential for recovery in RF values for f/t exposed specimens. However, the recoveries in RF values are not proportional to the hydraulic conductivity recovery of the specimens.