• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2002년도 학술논문발표회
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• pp.69-74
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• 2002

The following results are achieved from a mortar flow test depending on stainless steel slag fineness, replacement ratio, and a research on material age compressive strength, strength activity index. 1. Flow is proportional to the stainless steel slag fineness within the limits of 4000~8000$\textrm{cm}^2$/g, but in the case of fineness 20000$\textrm{cm}^2$/g flow decreases at all conditions except the case of replacement ratio 10%. 2. As stainless steel slag replacement ratio increases, Mortar of flow somewhat decreases. 3. As stainless steel slag blends, compressive strength decreases, but in proportion to the increase of age, compressive strength increases. 4. As stainless steel slag replacement ratio, compressive strength decreases. 5. In the case of stainless steel slag fineness 6000$\textrm{cm}^2$/g and 20.000$\textrm{cm}^2$/g, compressive strength of revelation ratio has the maximum value when it's replacement ratio is 10%.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.947-952
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• 2001

The prediction model is proposed to estimate the variation of compressive strength of fly ash concrete with aging. After analyzing the experimental result with the model, the regression results are presented according to fly ash replacement content and water/cement ratio. Based on the regression results, the influence of fly ash replacement content and water/cement ratio on apparent activation energy was investigated. According to the analysis, the model provides a good estimate of compressive strength development of fly ash concrete with aging. As the fly ash replacement content increases, the limiting relative compressive strength and initial apparent activation energy become greater. The concrete with water/cement ratio smaller than 0.40 shows that the limiting relative compressive strength and apparent activation energy are nearly constant according to water/cement ratio. But, the concrete with water/cement ratio greater than 0.40 has the increasing limiting relative compressive strength and apparent activation energy with increasing water/cement ratio.

• 한국공간구조학회논문집
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• 제17권3호
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• pp.83-90
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• 2017

Preservation of wooden structure due to deterioration and corrosion is based on preservation of original form, and wooden member should not be arbitrarily replaced or damaged. Accordingly, preservation processing method with synthetic resins is embossed. But it has an adverse effect because there is no exact standard for the reinforcement ratio with the synthetic. This paper experimental study for reinforcement ratio of wooden compressive member with synthetic resins, Reinforced ratio on section area of compressive member and direction. As a result, synthetic resin reinforcement selected as experimental variables by proper ratio enhanced compressive capacity of reinforced wooden member, than new wooden member.

• Structural Engineering and Mechanics
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• 제70권4호
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• pp.499-511
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• 2019

In this study, the axial compressive behavior of novel quadruple C-channel built-up cold-formed steel columns with different slenderness ratio was investigated, using the experimental and numerical analysis. The axial compressive capacity and failure modes of the columns were obtained and analyzed. The finite element models considering the geometry, material and contact nonlinearity were developed to simulate and analyze the structural behavior of the columns further. There was a great correlation between the numerical analyses and test results, which indicated that the finite element model was reasonable and accurate. Then influence of, slenderness ratio, flange width-to-thickness ratio and screw spacing on the mechanical behavior of the columns were studied, respectively. The tests and numerical results show that due to small slenderness ratio, the failure modes of the specimens are generally local buckling and distortional buckling. The axial compressive strength and stiffness of the quadruple C-channel built-up cold-formed steel columns decrease with the increase of maximum slenderness ratio. When the screw spacing is ranging from 150mm to 450mm, the axial compressive strength and stiffness of the quadruple C-channel built-up cold-formed steel columns change little. The axial compressive capacity of quadruple C-channel built-up cold-formed steel columns increases with the decrease of flange width-thickness ratio. A modified effective length factor is proposed to quantify the axial compressive capacity of the quadruple C-channel built-up cold-formed steel columns with U-shaped track in the ends.

• 콘크리트학회논문집
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• 제26권5호
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• pp.591-598
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• 2014

본 연구에서는 감수율에 따른 압축강도와 물-시멘트비의 관계를 평가하였으며, 감수율 3수준(0%, 8% 및 16%) 및 물-시멘트비 3수준(40%, 45% 및 50%)에 따른 콘크리트 배합을 제조하였다. 또한, 신뢰성 확보를 위하여 콘크리트 배합은 3회 반복실험을 실시하였다. 실험결과, 감수율에 따른 압축강도는 약 20% 이상의 강도차이가 발생하였으며, 감수율이 압축강도에 물-시멘트비 이상의 영향을 미치는 것으로 나타났다. 따라서 감수율의 영향을 반영한 새로운 압축강도와 물-시멘트비 관계식을 도출하였으며, 80% 이상의 높은 상관성이 있는 것으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.168-169
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• 2019

This study examined the effect of foam volume ratio and curing temperature the air dry density and compressive strength of lightweight concrete using bottom ash. Test results showed that the lightweight concrete possessed the compressive strength of 3.4~22.7 MPa at the air dry density of 1,041~1,583 kg/m3.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.26-27
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• 2015

The purpose of this study was to investigate the compressive strength property into concrete using rice straw ash.. In an effort to evaluate the effects of rice straw ash as mineral admixture, rice straw ash was mixed with cement at the mixture ratio of 0, 5, 10 and 15% relative to the cement weight. When the mixture ratio of rice straw ash was 10%, the highest compressive strength was observed, while the strength tended to decrease when the mixture ratio of rice straw ash was 15% even if it exhibited higher compressive strength than the plain. And it was observed that compressive strength of concrete containing rice husk ash was a similar a compressive strength of concrete containing silica fume.

• 한국안전학회지
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• 제19권2호
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• pp.104-111
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• 2004

The aim of this study was to investigate the influence of inorganic pigments on the physical properties of cement mortar. For this purpose, the compressive strength and absorption test were carried out on cement mortar imxed with inorganic pigments by changing the proportion of cement mortar, water-cement ratio, and ratio of pigment. The result of this study can be summarized as follows: the compressive strength of colored mortar rapidely increased in red and yellow mortar, as the mix ratio of pigment increased. In case of green and black mortar, however, the compressive strength decresed as the mix ratio incresed. In case of red and yellow mortar, the absorption of colored mortar increased as the mixing ratio increased, if the mean particle diameter of the pigment is small. In case of green and black mortar, the absorption ratio decreased as the mix ratio increased. After investigating the overall physical properties of colored mortar, it was confirmed that the proper mix ratio of pigment securing the properties of colored mortar was below 6% of the weight of the cement to be used.

• 한국농공학회논문집
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• 제57권2호
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• pp.67-73
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• 2015

This study evaluated the effects of fibers on the void ratio, compressive strength and repeated freezing and thawing resistance of porous vegetation concrete with binder type (non-sintering inorganic binder and blast furnace slag cement) and natural jute fiber volume fraction (0.0 %, 0.1 % and 0.2 %). The natural jute fiber volume fraction affected the void ratio, compressive strength and repeated freezing and thawing resistance. Added of natural jute fiber resulted in improved properties of the void ratio, compressive strength and freezing and thawing resistance. Also, the both compressive strength and freezing and thawing resistance increased with natural jute fiber volume fraction up to 0.1 % and then decreased with fiber volume fraction at 0.2 %.

• Geomechanics and Engineering
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• 제33권3호
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• pp.261-269
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• 2023

In this study, the compressive strength of cement stabilized soil was predicted using the electrical resistivity measurement. The effects of the water to cement (w/c) ratio and recovered Carbon Black (rCB) contents were examined. A series of electrical resistivity and compressive strength tests were conducted on two types of stabilized soil after 28 days of curing. Multiple nonlinear regression (MNLR) analysis was used to evaluate the relationship between the compressive strength and the electrical resistivity in terms of the rCB, C_u (uniformity coefficient), and w/c ratio. The results showed that the w/c ratio and C_u have a strong influence on the compressive strength and electrical resistivity of the cement stabilized soil compared to the rCB content. The use of a small amount of rCB led to a decrease in the void space in the specimen and was attributed to the increase strength and decrease electrical resistivity. A high w/c ratio also induced a low electrical resistivity and compressive strength, whereas 3% rCB in the cemented soil provided the optimum strength for all w/c ratios. Finally, a prediction equation for the compressive strength using the electrical resistivity measurement was suggested based on its reliability, time effectiveness, non-destructiveness, and cost-effectiveness.