• Computers and Concrete
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• 제10권6호
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• pp.649-662
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• 2012

This paper presents the results of an investigation on the compressive strength and weight loss of mortars containing three types of fillers as cement replacements; Limestone Filler (LF), Silica Fume (SF) and Trass (TR), subjected to elevated temperatures including $400^{\circ}C$, $600^{\circ}C$, $800^{\circ}C$ and $1000^{\circ}C$. Results indicate that addition of TR to blended cements, compared to SF addition, leads to higher compressive strength and lower weight loss at elevated temperatures. In order to model the influence of the different parameters on the compressive strength and the weight loss of specimens, artificial neural networks (ANNs) were adopted. Different diagrams were plotted based on the predictions of the most accurate networks to study the effects of temperature, different fillers and cement content on the target properties. In addition to the impressive RMSE and $R^2$ values of the best networks, the data used as the input for the prediction plots were chosen within the range of the data introduced to the networks in the training phase. Therefore, the prediction plots could be considered reliable to perform the parametric study.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.413-420
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• 2000

Cheju Island has nature of typical trass through volcanic activities in many times. The soil in Cheju Island has principally sprung from basalt and partially made up of trachyte, trachyte's nature and site. Also ancient relics, plain coarse pottery's kilns and pantiles kilns are homogeneously distributed all over the Cheju Island. In this study, as a result of X-ray fluorescence spectrometer and Mossbauer spectroscopy of a sample are from plain coarse pottery and pantiles in 5 regions of Cheju Island. It is thought that these samples are partially formed from neutral volcanic rock like trachyte and Atomicity state of iron is almost Fe$\^$3+/. Also the magnetic hyperfine field length of goethite, contained these samples is less than synthetic goethite magnetic hyperfine field length and this result shows that disintegration of inner magnetic order, created by partial substitution of diamagnetic positive ion containing Fe$\^$3+/ and Al$\^$3+/ in goethite lattice.

• 대한화학회지
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• 제55권3호
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• pp.490-494
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• 2011

이산화탄소 방출을 줄이기 위해 포트랜드 시멘트 성분 일부를 시멘트 보충재를 혼합해준 시멘트의 제조에 대해 연구하였다. 이산화탄소를 0.18 kg $CO_2$/kg 정도 줄이기 위해 포트랜드 시멘트에 보충재를 20 wt% 정도 혼합하였다. 이 혼합시멘트의 압축 강도는 포트랜드 시멘트 ASTM C-150의 표준치를 초과하며, 28일간의 굳는 과정중에 37 MPa의 압축 강도를 가졌다. 혼합시멘트의 미세구조는 포트랜드 시멘트와 유사하였다.