• Advances in concrete construction
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• v.11 no.3
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• pp.239-253
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• 2021

The behavior of concrete containing waste glass as a replacement of cement or aggregate was studied previously in the most of researches, but the present investigation focuses on the recycling of waste glass powder as a substitute for silica fume in high strength concrete (HSC). This endeavor deals with the efficiency of using waste glass powder, as an alternative for silica fume, in the flexural capacity of HSC beam. Thirteen members with dimensions of 0.3 m width, 0.15 m depth and 0.9 m span length were utilized in this work. A comparison study was performed considering HSC members and hybrid beams fabricated by HSC and conventional normal concrete (CC). In addition to the experiments on the influence of glass powder on flexural behavior, numerical analysis was implemented using nonlinear finite element approach to simulate the structural performance of the beams. Same constitutive relationships were selected to model the behavior of HSC with waste glass powder or silica fume to show the matching between the modeling outputs for beams made with these powders. The results showed that the loading capacity and ductility index of the HSC beams with waste glass powder demonstrated enhancing ultimate load and ductility compared with those of HSC specimens with silica fume. The study deduced that the recycled waste glass powder is a good alternative to the pozzolanic powder of silica fume.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.120-121
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• 2015

In this research, to evaluate the influence of using non-KS aggregate on concrete performance, the engineering properties of normal strength concrete were assessed depending on the KS aggregate and non-KS aggregate from various sources in mid-Korea. From the experiment, when the non-KS aggregate was used, low compressive strength was achieved with increased water-to-cement ratio caused by increased unit water due to high absorption rate of the non-KS aggregate.

• Journal of the Korean Ceramic Society
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• v.45 no.9
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• pp.497-506
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• 2008

The long time of twenty years has passed since Diesel Particulate Filter (DPF) was proposed before the practical use. The main factors that DPF has been put to practical use in this time, are the same time proposal of the evaluation method of SiC porous materials linked to he performance on the vehicle, and that the nature of thermal shock required for the soot regeneration (combustion of soot) in the DPF is different from the conventional requirement for the rather rapid thermal shock. For the requirements, these includ demonstrating utmost the characteristic of SiC's high thermal conductivity, and overcoming the difficulty of thermal expansion of SiC-DPF by dividing the filter into segments binding with the cement of lower Young's modulus, and the innovation of technology around the diesel exhaust system such as Common-Rail system. As the results of these, the cumulative shipments of SiC-DPF have reached about 5 million, and it goes at no claim in the market.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.81-84
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• 2005

Due to increased demands for durable and high-performance concrete structures, the use of admixtures has become essential. In this paper, material properties, and durability of concrete mixed with natural inorganic minerals(R-1) are obtained from test results. Through the comparisons with OPC(Ordinary Portland Cement) concrete, the R-1 concrete shows improved compressive strength and durability.

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.98-103
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• 2004

Shotcrete needs the enough durability without deterioration for life time. But shotcrete is being deteriorated according to aging like concrete by internal causes whithin itself and by external causes which can be physical, chemical, or mechanical. Durable shotcrete can be made by incresing the cement content, adding chemical and mineral admixtures and so on. So, in this study, chloride ion penetration test, freeze and thaw test, neutralization test were conducted to examine the durability characteristice of shotcrete with mineral admixtures such as silica fume, blast-furnace slag and fly ash. These results indicate that shotcrete with silica fume is durable. Therefore, the present study provides a firm base to make high performance shtcrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.139-144
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• 1998

This study is intended to devolop the self waterproof agents for high performance concrete by analyzing the properties of fresh and hardened mortar with various addition ratios of the inorganic admixture and zinc stearate. As the results of the test, the flow and air content increase with the addition of expansive additives. When the replacement rate of silica fume increases, the flow decreases for the increased viscidity. And the flow and sir content decrease with the addition of zinc stearate. At hardened state, the compressive strength, tensile strength and flexual strength decrease with the addition of expansive additives and zinc stearate. With the increase of silica fume's replacement, they show a little decrease at early age and then increase gradually. Also, absorption and permeability show a steep decrease when zinc stearate is added, and a slack decrease with the replacement of silica fume.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.04a
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• pp.29-32
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• 1991

This is the study on the performance of workability and engneering properties of flowing concrete using the superplasticizers, which are being used for control of the consistency of fresh concrete without modifying the properties of the hardened concrete and for production of high quality concrete at a low water-cement ratio. It is the aim of this study to analyze and investigate workability and engineering properties of flowing concrete according to the addition rate in poor and rich mix proportions of base concrete. Base on this fundamental investigation for the development of flowing concrete mix design, it could be drawn that the workability and engineering properties of flowing concreteare influenced greatly by mix proportion and dosage of superplasticizers.

• Computers and Concrete
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• v.10 no.6
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• pp.587-607
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• 2012

The purpose of this research is to propose a design technique of concrete mix proportions satisfying service life through genetic algorithm (GA) and neural network (NN). For this, thirty mix proportions and the related diffusion coefficients in high performance concrete are analyzed and fitness function for diffusion coefficient is obtained considering mix components like w/b (water to binder ratio), cement content, mineral admixture (slag, flay ash and silica fume) content, sand and coarse aggregate content. Through averaging the results of 10 times GA simulations, relative errors to the previous data decrease lower than 5.0% and the simulated mix proportions are verified with the experimental results. Assuming the durability design parameters, intended diffusion coefficient for intended service life is derived and mix proportions satisfying the service life are obtained. Among the mix proportions, the most optimized case which satisfies required concrete strength and the lowest cost is selected through GA algorithm. The proposed technique would be improved with the enhancement of comprehensive data set including wider the range of diffusion coefficients.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.571-574
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• 2000

When fresh concrete is exposed to low temperature, the concrete may suffer from the frost damage at early ages and the strength development may be delayed. To solve such problems of cold weather concreting admixtures called agent for enduring cold climate are developed to prevent the fresh concrete from being frozen at early ages. In this study, the experiments are carried out on several kinds of agent for enduring cold climate to present their performance. According to experimental results, most kinds of agent for enduring cold climate show the strength development in the range $-5^{\circ}C$ of curing temperature, it tends to be delayed at long term maturity without agents for enduring cold climate. while it gains high strength maturity when agents for enduring cold climate is applied.

• KCI Concrete Journal
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• v.13 no.1
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• pp.35-41
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• 2001

This paper investigated rheological properties of binder pastes for self-compacting high performance concrete. Six mixtures of self-compacting concrete were initially prepared and tested to estimate self-compacting property. Then, the binder pastes used in self-compacting concrete were tested for rheological properties using a rotary type rheometer. Binder pastes with different water-binder ratios arid flow values were also examined to evaluate their rheological characteristics. The binders were composed of ordinary Portland cement, fly ash, two types of pulverized blast-furnace slag, and limestone powder. The flow curves of binder pastes were obtained by a rotary type rheometer with shear rate control. Slump flow, O-funnel time, box, and L-flow teats were carried out to estimate self-compacting property of concrete. The flow curves of binder pastes for self-compacting concrete had negligible yield stresses and showed an approximately linear behavior at higher shear rates beyond a certain limit. Test results also indicated that the binders incorporating fly ash are more appropriate than the other types of binders in quality control of self-compacting concrete.