A Study on Appropriate Temperature Conditions and Functions in the Strength Estimation Method for Cement-Treated Soil Using Two Temperature Combination

Abstract

In this study, appropriate temperature conditions and functions were examined to obtain high estimation accuracy in a method for estimating the strength of cement-treated soil at arbitrary age using the strength of early age of the soil cured at two different temperatures. This strength estimation method utilizes an equivalent age and considers the effect of temperature during curing on the strength development of cement-treated soil. Unconfined compression tests were conducted on cement-treated soils cured under six different temperature conditions in the range of 20 to 55°C. Strength estimation was performed using three different functions for a total of 15 temperature combinations, and the estimation accuracy was evaluated. The results showed that when temperature conditions of 50°C or higher were used, the accuracy tended to be poor regardless of the estimation equation. When power functions were used, the difference from the measured values was larger than in other formulas, and there were cases where a significant decrease in estimation accuracy was observed. Under the conditions of this experiment, the evaluation index I_e of estimation accuracy was within 20% when the temperature condition was set to be between 20°C and 45°C and the temperature difference was within 20°C, and when an exponential function was used in the regression equation.