This study was aimed at synthesizing and characterizing cerium-doped titania. Cerium-doped anatase titania powders were prepared by sol-gel process, with ammonium (IV) nitrate and titanium (IV) butoxide as the raw materials. The characteristics of pure TiO2 and cerium-doped TiO2 were investigated by XRD, TG/DTA, FE-SEM, and UV-vis spectroscopy. The results of this study show that anatase type of TiO2 was obtained in as-prepared and calcined TiO2 and Ce-TiO2 powder. A DTA curve was also observed as the crystallization temperature decreased with increasing cerium contents. We found that the crystallite size of the obtained anatase particles decreased from 55 nm to 25 nm and the particle size decreased with increasing cerium contents. Moreover, UV-vis spectra showed that anatase titania powders with various cerium contents effectively extend the light absorption properties to the visible region.
In this study, the seismic performance of a Low-rise Pilotis Building with Eccentric Core is investigated. Low-rise Pilotis Buildings are very popular in Korea, but regarded as very weak structure to earthquake.
In this study, the seismic performance of a Low-rise Pilotis Building with Central Core is investigated. Low-rise Pilotis Buildings are very popular in Korea, but regarded as very weak structure to earthquake.
Recently, Earthquake occurrence in korea has become frequent, and the seismic safety of low-rise piloti buildings becomes more and more important. In this study, the differences in seismic performance between before and after reinforced by concrete filled steel tube (CFT) of low-rise central core type piloti building structures were compared.
Recently, Earthquake occurrence in korea has become frequent, and the seismic safety of low-rise piloti buildings becomes more and more important. In this study, the seismic retrofit method of low-rise eccentric core type piloti building structures using concrete filled steel tube (CFT) columns was analysed and verified for seismic performance.
Recently, Earthquake occurrence in korea has become frequent, and the seismic safety of low-rise piloti buildings becomes more and more important. In this study, the differences in seismic performance between before and after reinforced by concrete filled steel tube (CFT) of low-rise central core type piloti building structures were compared.
Recently, Earthquake occurrence in korea has become frequent, and the seismic safety of low-rise piloti buildings becomes more and more important. In this study, the seismic retrofit method of low-rise eccentric core type piloti building structures using concrete filled steel tube (CFT) columns was analysed and verified for seismic performance.
우리나라는 연 강수량의 60% 이상이 여름철인 6∼9월에 집중되며 국지적 집중호우로 인해 치수에 상당한 어려움을 겪고 있다. 또한 1960년대부터 급속한 산업화와 도시화에 따라 도시 지역에서 불투수성의 도로 포장면의 비율이 증가하고 있어 방재 성능이 크게 약화되는 문제가 발생하였다. 지표 불투수로 인한 문제를 해결하기 위해 국내·외 지자체에서 사회·환경적 문제에 대한 해결방안으로 투수성 콘크리트 포장을 시행하고 있으나, 투수성능을 증진시키기 위하여 잔골재가 적게 들어가는 투수성 콘크리트 포장은 일반 콘크리트 포장에 비해 내구성이 약화되는 문제가 발생한다.
본 연구에서는 국·내외 투수성 콘크리트 배합설계 및 기준을 조사하고, 투수성능 증진을 위해 잔골재를 첨가하지 않은 콘크리트 배합을 진행하였으며, 공극률 및 시멘트 페이스트량 결정을 위해 아스팔트 마샬 배합설계법의 최적 아스팔트함량 결정방법을 착안하여 배합설계를 수행하였다. 배합별 혼합물의 투수성능 및 내구성 평가를 위해 압축강도, 실내 투수시험 등을 진행하였으며, 최종적으로 투수성능을 유지하는 고내구성의 투수성 콘크리트 배합설계(안)을 제시하는데 그 목적이 있다.