Development of the quick prediction method for the strength of ground improved by jet grouting

The strength of cement-stabilised soil mixed using the jet grouting method is generally evaluated by the unconfined compressive strength of core samples after 28 days of curing. If the 28-day in situ strength of the soil‒cement mixture does not meet the design criteria, disposal of the deficient mixtures and reworking of the soil improvement are required, that may affect the construction period and cost. If the 28-day in situ strength can be predicted after a few days of mixing work, additional jet grouting work can be effectively performed if necessary, thereby reducing the impact on the construction schedule. In this study, laboratory tests were performed to estimate the 28-day strength of soil‒cement mixture specimens using accelerated curing at high temperature for a few days. The effects of accelerated curing and mixture conditions on the strength properties of the soil ‒ cement mixture specimens were investigated and the results validated the applicability of the high-temperature accelerated curing method for the evaluation of the 28-day strength.