Recently, a method of using blast furnace slag to reduce the amount of cement which generates a large amount of carbon dioxide during the manufacturing process has been studied. Blast furnace slag is a latent hydraulic property material and requires the use of alkali activator. However, alkali activator is expensive and have problems in use. Therefore, in this study, an alkali aqueous solution was used instead of an alkali activator. The alkaline aqueous solution used in this study was obtained by electrolysis of pure water and has strong alkalinity of pH12. As a result, we found that the use of alkali aqueous solution is effective in improving the reactivity of blast furnace slag.

The purpose of this study was to evaluate flowability of engineered cemetitious composite(ECC) Using blast furnace slag and fly ash as a binder in mixture. From the test result, flowability value of all ECC mixtures show good flowability and self compacting performance.

In general, polymer cement mortars that is made from organic polymer dispersion and cement have good workability compared with ordinary cement due to ball-bearing acting of polymer particles in cement mortar. The purpose of this study is to evaluate the workability of cement mortar according to adding of admixtures such as polymer dispersions, blast-furnace slag and fly ash. From the test results, the flow of polymer-modified mortars is increased with increasing polymer-cement ratio, and also is a little improved according to adding of fly ash compared to blast-furnace slag.

In this study, it was developed geopolymer concrete of alkali-activated using the mixed fly ash and blast furnace slag. and it was developed the interlocking block using the developed geopolymer concrete. In addition, the bending strength and water absorption rate of the interlocking block was tested by KS standard. The test results were as follows. The water adsorption ratio of the BSF4 specimen was under 10%, and the flexural strength of that was over 5MPa

In this study, blast resistant performance of steel plate concrete (SC) and RC wall against blast load is compared. In order to quickly and easily perform the sensitivity analysis of blast response to explosion design variables, an equivalent single degree of freedom (SDOF) dynamic analysis program was developed. By analyzing more than 800 design variables, we could understand the effect of variables on blast resistant performance.

The effect of loading on chloride penetration into concrete is evaluated in this study. It is found that the chloride pene- tration rates for OPC concrete and blast furnace slag BFS concrete under the tensile stress were increased by 29% and 77%, respectively. The diffusion coefficient of FA and BFS concrete was lower than that of conventional concrete without BFS, no loads and stress states. Under tensile stress, the diffusion coefficient for FA and BFS, plain concrete showed higher values with increasing stress. The influence of specific surface area on the diffusion coefficient was investigated. As a result, the larger the specific surface areas of BFS are the lower diffusion coefficients. This tendency was more pronounced under the high stress conditions. The chloride penetration depth was distributed uni- formly when no stress was applied. However, in the case of tensile loading, the diffusion depth was not distributed uni- formly, and showed prominent characteristics. This result indicates that analysis using average values of chloride pene- tration depth is not proper under load conditions.

The purpose of this study was to evaluate flowability of engineered cemetitious composite(ECC) Using blast furnace slag and fly ash as a binder in mixture. From the test result, flowability value of all ECC mixtures show good flowability and self compacting performance.

In general, polymer cement mortars that is made from organic polymer dispersion and cement have good workability compared with ordinary cement due to ball-bearing acting of polymer particles in cement mortar. The purpose of this study is to evaluate the workability of cement mortar according to adding of admixtures such as polymer dispersions, blast-furnace slag and fly ash. From the test results, the flow of polymer-modified mortars is increased with increasing polymer-cement ratio, and also is a little improved according to adding of fly ash compared to blast-furnace slag.

In this study, it was developed geopolymer concrete of alkali-activated using the mixed fly ash and blast furnace slag. and it was developed the interlocking block using the developed geopolymer concrete. In addition, the bending strength and water absorption rate of the interlocking block was tested by KS standard. The test results were as follows. The water adsorption ratio of the BSF4 specimen was under 10%, and the flexural strength of that was over 5MPa.

Rice blast, caused by a fungus Magnaporthe oryzae, is one of the most devastating diseases of rice worldwide. Analyzing the valuable genetic resources is important in making progress towards blast resistance. Molecular screening of major rice blast resistance (R) genes was determined in 2,509 accessions of rice germplasm from different geographic regions of Asia and Europe using PCR based markers which showed linkage to twelve major blast R genes, Pik-p, Pi39, Pit, Pik-m, Pi-d(t)2, Pii, Pib, Pik, Pita, Pita/Pita-2, Pi5, and Piz-t. Out of 2,509 accessions, only two accessions had maximum nine blast resistance genes followed by eighteen accessions each with eight R genes. The polygenic combination of three genes was possessed by maximum number of accessions (824), while among others 48 accessions possessed seven genes, 119 accessions had six genes, 267 accessions had five genes, 487 accessions had four genes, 646 accessions had two genes, and 98 accessions had single R gene. The Pik-p gene appeared to be omnipresent and was detected in all germplasm. Furthermore, principal component analysis (PCA) indicated that Pita, Pita/Pita-2, Pi-d(t)2, Pib and Pit were the major genes responsible for resistance in the germplasm. The present investigation revealed that a set of 68 elite germplasm accessions would have a competitive edge over the current resistance donors being utilized in the breeding programs. Overall, these results might be useful to identify and incorporate the resistance genes from germplasm into elite cultivars through marker assisted selection in rice breeding.

Blast resistance of 29 rice cultivars confirmed as a durable resistance in the evaluation of sequential planting from 2004 to 2006 was evaluated to nursery screening in 14 test sites during 11 years in Korea. The average disease severity (ADS) of 29 rice varieties against rice blast showed 3.5 degree; however, the difference of disease severity among the varieties was from 1.9 to 4.8. The 29 varieties were grouped into resistance less than 3.0 ADS degree including 12 varieties and moderate resistance over 3.1 ADS degree including 17 varieties. Among the 12 rice cultivars presented low ADS, 4 rice cultivars, Ungwang, Pungmi 1, Sinunbong 1, and Dasan 1 were constantly appeared high resistant reaction during 11 years in all test sites and the others were showed various diseases severity across the test years and the test sites. Twenty-one rice cultivars including Gopum were more variable among the test sites while the others were higher variable among the test years. These results indicated that durable resistance test against rice blast using sequential planting is a very efficient screening method to predict durability and nursery test for long periods and also useful method to predict indirectly durable resistance of rice cultivars.

The purpose of the present study is to investigate some effects of concrete according to addition of blast furnace slag and sulfuric alkali-activator. Blast furnace slag was used at 30~80% replacement by weight of cement, and liquid sulfur having NaOH additives was chosen as the alkaline activator. In order to evaluate characteristics of blast furnace slag concrete with sulfuric alkali activators, compressive strength test, carbonation test were performed.

In this study, sensitivity analyses on the blast response of the steel-plate concrete(SC) walls subjected to explosive blast loads were carried out. In order to evaluate various cases effectively we set up the blast response evaluation procedure of SC walls, and developed the blast response evaluation program of SC walls using equivalent SDOF method. Finally, the effects of the various design parameters on the blast response of SC walls were investigated using the developed program.

본 연구에서는 경량기포 콘크리트를 이용한 육성용 토양골재의 적용성을 평가하기 위해서 고로슬래그 기반 기포콘크리트의 총 8 배합과 인공토양골재를 제조하였다. 고로슬래그 기반 기포콘크리트 배합의 주요변수는 단위결합재량으로서 100에서 800 kg/m3으로 변화하 였다. 경량기포콘크리트는 플로우, 슬러리 및 절건 밀도와 재령별 압축강도를 측정하였으며, 파쇄된 인공토양골재는 pH, 입도분포, 투수계수, 양이온치환용량(CEC), 유기물함유량(C/N비)을 측정하였다. 측정결과 경량기포콘크리트의 플로우, 슬러리 및 절건밀도와 재령별 압축강도는 단위결합재량이 증가함에 따라 증가하였다. 경량기포콘크리트의 단위결합재량이 500 kg/m3 이상인 배합의 28일 압축강도는 4 MPa 이상이었 다. 인공토양골재에 3일 이상의 15% 희석된 제1인산암모늄의 수용액침지는 pH를 저감시키는데 효과적이었다. 또한 제조된 인공토양골재는 양이온 치환용량(CEC) 측면에서 상급으로 평가되었지만 C/N비 측면에서는 조경시방서를 만족시키지 못하였다.

Even though high performance concrete was developed according to becoming bigger and higher of reinforced concrete building, the rheological evaluation is not enough to use as input data to accomplish the numerical analysis of construction design. Consistency curves were measured by the viscometer as hydration reaction time passed. There are a sudden change of viscosity and yield stress around initial setting in case of low W/B. The increase of workability by the change of free water in cement paste was offset by the coating effect of impermeable layer in case of W/B 40%.

In this study, a study on the structural safety evaluation method of steel-plate concrete(SC) walls subjected to explosive blast loads were carried out. Various approaches to assess the blast response were reviewed, such as static method, equivalent SDOF method, explicit FE method, and computational fluid-dynamic method. Finally, preliminary blast response evaluation of SC walls were performed using equivalent SDOF method.

This study evaluates the material performance of slump value and compressive strength of the concrete which was made by recycled sand and blast furnace slag powder(BFSP). The main variables are replacement ratio of BFSP. As a result, it was evaluated that more detailed evaluation is needed in long-term strength development and the compensation of slump value to the replacement ratio of BFSP.

The study is compressive strength of 110MPa PHC pile using ground granulated blast furnace slag to NAC, AC curing method. In the result, 20% of ground granulated blast furnace slag could be substituted for cement in PHC pile concrete.

This paper presents the results of an experimental test conducted subjected to blast loading of steel plates. An experimental results were compared with the simulation result derived in AUTODYN to validate the simulation method used in this study.

In experimental results, the prediction equation for 28 day-strength of GGBF slag concrete could be produced through the linear regression analysis of early strength and 28 day-strength. In order to acquire the reliability, all mixture were repeated as 3 times and each mixture order was carried out by random sampling. The prediction equation for 28 day-strength of GGBF slag concrete by 1 day strength won the good reliability.