• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.307-312
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• 1998

Recently the study on high flowing concrete which has high workability and Self-compacting is being proceeded actively in the university and corporative laboratory. There are some cases that has been applied to the field. This high flowing concrete has higher fluidity and segregation resistance than Plain of flowing concrete. And it is being focused as a remarkable know-how which can make high-quality concrete and reduction effect of labor force. This properties of high flowing concrete are influenced by the relationship of several factors; binder content, water binder ratio and unit water content. It is the aim of this study to propose reference data at mix design of high flowing concrete, after comparing and analyzing the fluidity and strength properties of high flowing concrete according to water binder content ratio and unit water content.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.129-153
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• 1996

In aqueous slurry processing of silicon nitride, the interaction of dispersant and binder on the surface of particles was studied to identify the effect of these additives on ceramic powder processing. Polymethacrylic acid (PMAA) and polyvinyl alcohol (PVA) were used as dispersant and binder, respectively. the adsorption isotherms of PMAA and PVA for the silicon nitride suspension were determined, while the adsorption of PMAA was differentiated in the mixed additive system by ultraviolet spectroscopy. These experiments were done in order to investigate the effect of these organic additives on the physicochemical properties of silicon nitride suspensions. The electrokinetic behavior of silicon nitride was subsequently measured by electrokinetic sonic amplitude (ESA). As PMAA adsorbed onto silicon nitride, the isoelectric point (pHicp) shifted from pH=6.7 to acidic pH, depending on the surface coverage of PMAA. However, adsorption of PVA did not change the pHicp of suspensions, but did decrease the surface potential of silicon nitride moderately. The rheological behavior of silicon nitride suspensions was measured to assess the stability of particles in aqueous media, and was correlated with the electrokinetic behavior and adsorption isotherm data for silicon nitride.

• Journal of the Korea Institute of Building Construction
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• v.3 no.4
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• pp.79-86
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• 2003

The purpose of study is to offer base data for high fluid concrete mix property, as grasp effect of aggregate to reach much more effect for producing high fluid concrete. For this study, there are three types of combined aggregates, river sand + river aggregate(type A), river sand + crusted aggregate(type B), washed sea sand + crushed aggregate(type C) and take a factor, water-contents, water-binder ratio and S/a. And so, we had following conclusion, resulting application-ability of high fluid mortar by K-slump tester to use a handy consistency measuring instrument. And so, we had following conclusion, resulting application-ability of high fluid concrete by K-slump tester to use a handy consistency measuring instrument. 1) In cafe of regular water binder ratio, high fluid concrete suffered much effect of combined aggregates and water binder ratio. Range of water binder ratio by combined aggregates is w/b 0.4 downward(type A and B), w/b 0.35 downward(type C). 2) Water contents to need for producing high fluid concrete is minimum 170kg/$\textrm{m}^3$ without regard to combined aggregates. 3) The effect of S/a on high fluid concrete by combined aggregates is approximately S/a 50% (type A and B), s/a 50-55% (type C). 4) Consistency measuring of high fluid concrete by K-slump tester is possible and first indication value, high fluid concrete can be produced, is 6~10.5cm.

• Computers and Concrete
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• v.6 no.2
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• pp.155-165
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• 2009

Splitting tensile strength (STS) of high-performance concrete (HPC) is one of the important mechanical properties for structural design. This property is related to compressive strength (CS), water/binder (W/B) ratio and concrete age. This paper presents a clustering-based fuzzy model for the prediction of STS based on the CS and (W/B) at a fixed age (28 days). The data driven fuzzy model consists of three main steps: fuzzy clustering, inference system, and prediction. The system can be analyzed directly by the model from measured data. The performance evaluations showed that the fuzzy model is more accurate than the other prediction models concerned.

• Computers and Concrete
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• v.31 no.6
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• pp.545-559
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• 2023

In this study, an experimental investigation was conducted to assess the influence of ground granulated blast furnace slag (GGBS) and silica fume (SF) on the fresh and hardened properties of grout specimens and preplaced aggregate concrete (PAC). Grout proportions were optimized statistically using a factorial design and were applied to 10 mm and 20 mm coarse aggregates to produce PAC. The results demonstrate that GGBS has a more significant effect on the compressive strength of grout compared to SF, with a small increase or decrease in the GGBS content having a greater influence on the compressive strength of grout than SF. The water to binder ratio had the most significant effect on the compressive strength of PAC, followed by the coarse aggregate size and sand to binder ratio. An empirical relationship to predict the compressive strength of PAC was proposed through an experimentally derived factorial design along with a statistical analysis of collectively obtained data and a deep literature review. The results predicted by the empirical relationship were in good agreement with those of PAC produced for verification.

• Computers and Concrete
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• v.24 no.2
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• pp.137-150
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• 2019

In this paper, surrogate models such as multivariate adaptive regression splines (MARS) and M5P model tree (M5P MT) methods have been investigated in order to propose a new formulation for the 28-days compressive strength of self-compacting concrete (SCC) incorporating metakaolin as a supplementary cementitious materials. A database comprising experimental data has been assembled from several published papers in the literature and the data have been used for training and testing. In particular, the data are arranged in a format of seven input parameters covering contents of cement, coarse aggregate to fine aggregate ratio, water, metakaolin, super plasticizer, largest maximum size and binder as well as one output parameter, which is the 28-days compressive strength. The efficiency of the proposed techniques has been demonstrated by means of certain statistical criteria. The findings have been compared to experimental results and their comparisons shows that the MARS and M5P MT approaches predict the compressive strength of SCC incorporating metakaolin with great precision. The performed sensitivity analysis to assign effective parameters on 28-days compressive strength indicates that cementitious binder content is the most effective variable in the mixture.

• International Journal of Highway Engineering
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• v.7 no.1 s.23
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• pp.63-71
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• 2005

Asphalt binder grading is to specify quality of asphalt binders relating to pavement performance in orderly manner, and provides the necessary information in selecting the appropriate asphalt binder for the hot mix design. For this purpose, United States has developed the PG-grading in 1995 and is implementing in practice. Recently, this American PG-grading system has been accepted as the domestic binder grading specification. However, the Asian (including Japan and China) and the most European countries are still use the traditional penetration and viscosity specification. The goal of this study lies in analysing the American PG-grading for its justification. As the result, the serious errors are found, and thus, to eliminate the errors, the more precise binder grading equation is introduced, Credibility of this study is checked by predicting the literature rut data with the equations mentioned. The prediction result are validating the claimes made in this study.

• International Journal of Highway Engineering
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• v.7 no.2 s.24
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• pp.57-67
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• 2005

Almost most of literatures treat behaviors of asphalt binders as a homogeneous single-phase fluid, but this generalization turns out to be a serious mistake. This study introduces all the characteristic equations for asphalt binders, which are modified or unmodified. Especially, characteristic equations for a unhomogeneous multi-phase fluid for modified asphalts is first time proposed. Characteristics of each equations introduced are explained by employing dynamic shear testing data actually measured for specific asphalt binders. Differences of moving behaviors and characteristic equations between a homogeneous single-phase and a unhomogeneous multi-phase fluid are emphasized. These differences help us understand which characteristic equations must be used for a given asphalt fluid and what kinds of properties must be investigated for analysis of a specific asphalt binder. Results of this study provide how to analyse modified and unmodified asphalts, and informations necessary for binder grading.

• Composites Research
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• v.35 no.2
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• pp.69-74
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• 2022

In this study, the conductive paste used in a wide range such as wiring in the electronic packaging field, the automobile industry, and electronic products is manufactured under various process conditions due to the simplicity of the process, and then the thermal, mechanical, and electrical characteristics are analyzed and simulation studies are conducted to optimize the process. to establish the conditions of the conductive paste manufacturing process. First, a conductive paste was prepared by setting various types of binder resin, an essential component of the conductive paste, and characteristics such as thermal conductivity, tensile strength, and elongation were analyzed. Among the binder resins, the conductive paste applied with a flexible epoxy material had the best physical properties, and a simulation study was conducted based on the physical property data base of the conductive face. As a result of the simulation, the best physical properties were exhibited when the Ag flake volume fraction was 60%.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.705-710
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• 2002

Recently, there has been for a number of reasons growing interest in the use of porous concrete, and it is used as an ecological material. But, because the valuation methods of the quality on the fresh porous concrete aren't established up till now, it is difficult that the harden porous concrete is made sure of its required quality. This study is to present the measurement method of the void ratio on the fresh porous concrete and to analyze the influence of water-cement ratio and vibrating time on the binder content covered a coarse aggregate. Results of this study were shown as follows; The measurement methods of the void ratio and aggregate-binder weight ratio on the fresh porous concrete can be useful as data for the quality control of fresh porous concrete.