Lime-Fly Ash/Rice Husk Ash에 의한 해성 퇴적토의 강도특성 개선

Abstract

본 연구에서는 울산광역시 남구 삼산동 일원의 지표 하 7m 지점에서 채취한 시료에 대하여 생석회 처리 후 FA(fly ash)와 RHA(rice husk ash)를 혼합하여 강도특성을 분석하였다. 연구방법으로는 채취한 시료와 혼합토에 대하여 기본물성시험과 일축압축강도 시험 및 C.B.R 시험을 실시하였다. 그리고 첨가재의 혼합에 따른 입자구조를 분석하기 위하여 주사전자현미경(SEM)을 이용하여 비교 · 검토하였으며, 첨가재의 화학적 구성성분을 X-선 형광분석(XRF)을 통하여 조사하였다. 화학성분 분석결과, FA의 주 구성성분은 Al2O3, Fe2O3가 약 50%, RHA의 경우는 SiO2가 약 91%를 차지하는 것으로 나타났다. 일축압축강도 시험결과, FA와 RHA가 각각 10% 첨가시 가장 큰 강도를 나타내었으며, 10% 이상 첨가시 강도가 저하되는 경향을 나타내었다. FA와 RHA가 각각 10% 첨가된 시료에 대한 C.B.R 시험결과에서 전자의 경우 118%, 후자의 경우 100%를 나타내었으며, 소성지수(PI)가 각각 9.4%, 9.1%값을 나타내어 소성지수 저감 후 보조기층, 기층재로써 사용이 가능할것으로 판단되었다.

In this paper, a laboratory investigation was carried out to estimate the strength improvement of quicklime mixture with fly ash and rice husk ash for the effective use of surplus soils, and the shear strength with curing time was estimated at lime 10 percent with the change of fly ash and rice husk ash content. The effect of strength improvement has been established through the change of fly ash and rice husk ash content from the samples taken at Samsan region, Ulsan. The change in the microstructure of materials was investigated by using the scanning electron microscope(SEM). The chemical composition of materials was investigated by using the X-ray fluorescence spectrometer(XRF).

The result of XRF analysis indicate that Al2O3 and Fe2O3 contents of fly ash is about 50%, SiO2 content of RHA is about 91%. The results of another tests indicated that the presence of lime with fly ash and rice husk ash encouraged the stabilization efficiency of lime with fly ash and rice husk ash, and increased shear strength. Furthermore, it is necessary for inquiring into the relationship between the characteristics of strength and the chemical components.

Key words : fly ash, rice husk ash, quick1ime, surplus soils, SEM, XRF

In this paper, a laboratory investigation was carried out to estimate the strength improvement of quicklime mixture with fly ash and rice husk ash for the effective use of surplus soils, and the shear strength with curing time was estimated at lime 10 percent with the change of fly ash and rice husk ash content. The effect of strength improvement has been established through the change of fly ash and rice husk ash content from the samples taken at Samsan region, Ulsan. The change in the microstructure of materials was investigated by using the scanning electron microscope(SEM). The chemical composition of materials was investigated by using the X-ray fluorescence spectrometer(XRF).

The result of XRF analysis indicate that Al2O3 and Fe2O3 contents of fly ash is about 50%, SiO2 content of RHA is about 91%. The results of another tests indicated that the presence of lime with fly ash and rice husk ash encouraged the stabilization efficiency of lime with fly ash and rice husk ash, and increased shear strength. Furthermore, it is necessary for inquiring into the relationship between the characteristics of strength and the chemical components.

Key words : fly ash, rice husk ash, quick1ime, surplus soils, SEM, XRF