FRESH AND HARDENED PROPERTIES OF CONTROLLED LOW-STRENGTH MATERIAL MADE FROM LIME KILN DUST AND BOTTOM ASH AS A BINDER

This article studies the fresh and hardened properties controlled low-strength material made from lime kiln dust (LKD) and bottom ash (BA) as a binder. LKD used in this study was divided into 2 types which were the soft burning at temperature 900 °C (SLD) and hard burning at temperature 1,300 °C (HLD). The binary ratios of BA:SLD and BA:HLD were set at 85:15, 70:30, and 55:45 by weight. Additionally, the ternary binder ratios of BA:SLD:HLD at 55:15:30, 55:30:15, and 70:15:15 by weight were also used in this study. A binder to sand ratio was set at 1:2.75 by weight. The water to binder ratio was constant at a 0.7 and the flow of controlled low-strength material was controlled between 200-250 mm. The fresh density, setting time, unconfined compressive strength, and elastic modulus of controlled low-strength material were investigated. The results revealed that the increase of LKD content resulted in increasing the fresh density and decreasing the setting times of the controlled low-strength material. The controlled low-strength material with a ratio of BA:SLD at 55:45 by weight had the highest unconfined compressive strength which was 7,750 kPa at 28 days. Additionally, the elastic modulus of controlled low-strength material tended to increase with the increase of unconfined compressive strength. This result was suggested that the use of LKD mixed with BA could produce the controlled low-strength material.