Abstract
Soil that is generated as a byproduct of construction work but that lacks sufficient strength for use as foundation material without modification has been disposed of as industrial waste. For effective use as a resource, such soil is increasingly being modified with solidification agents and reused as an embankment material. Hokkaido is in cold, northern Japan, which means that soil modified during the winter may not begin to develop strength until the air temperature rises beyond a certain point. Unfortunately, very few studies have addressed how curing temperature affects the ultimate strength of modified soil. To determine those effects, the authors obtained strengths of modified unsuitable soil under various curing temperatures and durations. The following were found: 1) When the curing temperature is constant, the ultimate soil strength achieved by curing at 5°C or -20°C is lower than that achieved by curing at 20°C. 2) When the initial curing temperature is low, great ultimate soil strength can still be achieved if the curing temperature is subsequently raised. 3) When the initial curing temperature is -20°C, the ultimate strength will be small even if the curing temperature is raised afterwards.
