• 한국도로학회논문집
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• 제18권2호
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• pp.61-71
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• 2016

PURPOSES: The objective of this study was to determine the optimum ratio of mix design, for a reclaimed asphalt pavement (RAP) content of 100%, for spray injection application. METHODS: A literature review revealed that spray injection is an efficient and cost-effective application for fixing small defective regions of an asphalt pavement. Rapid-setting polymer-modified asphalt mixtures prepared from two types of rapid-setting polymer asphalt emulsion were subjected to Marshall stability and wet track abrasion tests, in order to identify the optimum mix designs. RESULTS and CONCLUSIONS : Different mix designs of type A and type B emulsions were prepared using RAP and virgin aggregates, in order to compare the performance and determine the optimum mix design. The performance of mixtures prepared with RAP was superior to that of mixtures containing virgin aggregates. Moreover, for optimum ratio of the design, the binder content prepared from RAP was set to 1~2% lower than that consisting of virgin aggregates. Compared to their Type A counterparts, type B mixtures consisting of a reactive emulsion performed better in the Marshall stability and wet track abrasion tests. The initial results confirmed the advantages associated with using RAP for spray injection applications. Further studies will be performed to verify the difference in the optimum mix design and performance obtained in the lab-scale test and tests conducted at the job site by using the spray injection machine.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.356-361
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• 1998

Permeable polymer cement concrete in this study is one of the invironment conscious concretes that can be applied at roads, side walks, parking lots, interlocking block and river embankment, etc. In this study, permeable polymer cement concretes using polymer dispersion(St/Ac) with water-cement ratios of 25, 30, 35 and 40%, polymer-cement ratios of 0, 5, 10, 15 and 20%, and a ratio of cement to aggregate (by weight), 1 : 3.5(about 415kg/㎥), 1 : 4.0(about 375 kg/㎥), and 1 : 4.5(about 345kg/㎥) are prepared, and tested for compressive, flexural and tensile strength, and permeability. From the test results, increase in the strengths of permeable polymer cement concrete are clearly observed with increasing polymer-cement ratio, we can obtain the maximum strengths at water-cement ratio of 35%. The optimum permeable polymer cement concrete according to application and location of work can be selected in various mix proportions.

• Advances in materials Research
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• 제4권3호
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• pp.179-192
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• 2015

The study presents a preliminary investigation on the applicability of Shirasu (a pyroclastic flow deposit characterized by high percentage of volcanic glass) in geopolymer. Comparative study on compressive strength and internal pore structure has been done between geopolymers with alkali activated Shirasu and fly ash as aluminosilicates. Mortar mix proportions are selected based on variations in ratio of alkaline activators to aluminosilicate and also on silica to alkali hydroxide ratio. From the experimental study, Shirasu geopolymer exhibited fairly good compressive strength. Mix proportion based on silica to alkali hydroxide ratio is observed to have profound effect on strength development.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.270-271
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• 2014

In this study, a replacement ratio of blast furnace slag coarse aggregate and a water binder ratio by an optimum combination of PHC file was investigated. As a results, the target strength 78.5MPa was altogether satisfied in a mix proportion 28-G100-SG0 and W/B ratio 26 %. The surface rupture was generated in 28-G0-SG100 combination after curing with the autoclave. According to the result of measuring the ingredient, the majority were the MgOH2 hydrate.

• 콘크리트학회논문집
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• 제12권6호
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• pp.91-98
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• 2000

Porous concrete having continuous voids is gaining more interest as an ecological material. It has several useful functions such as water and air permeability, sound absorption, etc. Its strengths are considerably lower than those of conventional concrete due to the large and continuous voids in it. This study has been carried out to investigate the influence of mix factors and mixture proportion of aggregate on the strengths and water permeability of porous concrete. And it has been carried out to investigate the evaluation of void of porous concrete by the ultra-sonic pulse velocity. The results f this study are as follows: 1) The theoretical void ratio has greater influence than any other factor on the strengths and water permeability of porous concrete. And it is a little affected by the replacement proportion of silica-fume and mixture proportion of aggregate. 2) Because the coefficients of correlation between the void ratio and ultra-sonic pulse velocity were relatively high, it will be possible that the void ratio is predicted by the ultra-sonic pulse velocity.

• Asian-Australasian Journal of Animal Sciences
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• 제16권9호
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• pp.1374-1383
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• 2003

The effect of applying edible coating and addition of antioxidants (butylated hydroxyanisole (BHA) plus butylated hydroxytoluene (BHT) in a 1:1 ratio) on pork patties were investigated prior to achieve desired physico-chemical, microbiological and sensory qualities. For this, five treatments were conducted as (i) control (neither coated nor antioxidants treated); (ii) coated without antioxidants treated; (iii) coated and antioxidants added in the batter mix only (100 ppm); (iv) coated and antioxidants added in meat mix (100 ppm) only; and (v) coated and antioxidants added both in the batter mix (50 ppm) and the meat mix (50 ppm). Addition of antioxidants both in the batter mix and the meat mix significantly (p<0.05) reduced the microbial loads and thiobarbituric acid (TBA) values. The TBA values significantly (p<0.05) increased up to day 14 and then progressively increased with the advancement of each interval of storage days up to 28 days. Total plate count significantly (p<0.05) increased with the increase in storage days.Coliform and Staphylococcus aureus were absent throughout the storage days in all samples. Staphylococcus aureus however, were present in the control group at day 14 and in enrobed (coated) patties (without antioxidants treated) at 28th day. Addition of antioxidants to batter mix and meat mix did not substantially enhance bacteriostatic activity. Application of coatings and antioxidants retarded the loss of firmness, flavor, changes in appearance and color, and also other sensory attributes. Control patties were better with respect to microbial quality and TBA values but had poorer sensory quality than coated patties.

• KCI Concrete Journal
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• 제14권4호
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• pp.151-159
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• 2002

This study investigates experimentally the optimum mix proportion and design factors of the stabilizing liquid used for excavation of the massive and deep slurry wall in LNG in-ground tank before pouring concrete. Considering those site conditions, the stabilizing liquid used for excavation of slurry wall has to be satisfied with some requirements including specific gravity, fluid loss, cake thickness, funnel viscosity and sand content in order to construct the safe and qualified slurry wall. For this purpose, we select materials including bentonite, polymer and dispersion agent. After performing many tests for materials and mix design process, we propose the optimum mix proportion that the upper limit ratio of bentonite is $2.0\%$, polymer is $0.1\%$ considering the funnel viscosity and dispersion agent is $0.05\%$considering the fluid loss of the stabilizing liquid. Also, we select all materials which are consisted of GTC4 as bentonite, KSTP as polymer and Bentocryl 86 as dispersion agent. Based on the results of this study, the optimum mix proportion of the stabilizing liquid is applicable to excavate the deep and massive slurry wall in LNG in-ground tank successfully.

• 콘크리트학회지
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• 제6권4호
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• pp.131-140
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• 1994

최근들어 고속도로, 고속철도, 지하철 등의 건설이 급격히 증가함에 따라 터널의 건설이 늘어나고 있다. 이러한 터널등의 건설에서 필수적으로 따르는 것이 shotcrete의 시공이며 이러한 shotcrete의 시공은 앞으로 더욱 증가할 추세에 있다. 그러나 shotctete의 광범위한 시공에도 불고하고 현재 여러 가지 문제점을 내포하고 있는 것이 사실이다. 따라서, 본 연구에서는 우리나라 현행 shotcrete의 현황과 문제점을 알아보고, 실내실험 및 현장 모형실험의 광범위한 실험을 통해 최적배합으로 도축하였다. 이 때 적정의 소요강도를 발현하면서 리바운드율이 최소인 배합을 최적배합으로 하였다. 결국 본 연구에서 도출된 최적배합은 앞으로 우리나라에서 성능이 우수하고 고품질의 shotcrete시공을 위한 중요한 토대를 제공하게 될 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1897-1902
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• 2018

Objective: This study was conducted to evaluate the effect of homo or hetero fermentative inoculants on fermentation quality and aerobic stability of sweet potato vine (SPV) silage containing Italian ryegrass hay as moisture absorbent. Methods: The SPV was harvested at 15% dry matter, mixed with Italian ryegrass hay at 1:1 ratio on a fresh weight basis, and chopped to 3 to 5 cm length. After then, the chopped forage mixture was ensiled into 20-L mini silos in quadruplicate for 7, 48, and 100 days after application of microbial inoculants at $1.2{\times}10^5$ colony forming units (cfu)/g of forage following: no inoculant (CON), Lactobacillus plantarum as a homo fermentative (LP), Lactobacillus buchneri as a hetero fermentative (LB), and mixture of LP and LB at 1:1 ratio as a combo fermentative (MIX). Results: The LP and MIX silages had lowest pH (p<0.001) on 7 and 48 days, while MIX and CON silages had greatest lactate concentrations (p<0.05) on 7 and 48 days, respectively. Acetate concentrations were highest (p<0.01) in LB and MIX silages on 7 days, and in LB silage on 48 days, while lactate to acetate ratios were lowest (p<0.001) in LB silages. The chemical compositions and nutrient digestibility of silage ensiled for 100 days was not affected by inoculants. On 100 days of ensiling, LB silage had lowest (p<0.01) lactate concentration and lactate to acetate ratio, but highest acetate concentration. Aerobic stability was highest (p<0.001) in LB silage followed in MIX silage. On contrast, LB silage had lowest (p<0.05) lactic acid bacteria and mold. Conclusion: The results indicated that application of LB solely had a better effect on aerobic stability than not only LP, but also MIX. However, LP application did not show beneficial effects from the viewpoints of fermentation quality and aerobic stability compared to CON.

• 한국건축시공학회지
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• 제5권1호
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• pp.63-68
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• 2005

Generally, aggregate may limit the workability, strength and durability of concrete, and good concrete cannot be made with aggregate of bad property including low strength, bad shape and grading. But recently, it has been insufficient in quantity to collect good natural aggregate because of exhaustion of aggregate resources. In case of Korea, the using ratio of crushed stone occupies about 97 percent of total coarse aggregate, and ratio of crushed sand occupies about 18.3 percent of total fine aggregate. This is an experimental study to compare and analyze the properties of crushed sand for concrete in capital region and concrete according to the replacement ratio of crushed sand to improve quality and mix design of concrete using crushed sand. According to test results, it was found that nearly all the properties of crushed sand satisfied with the value recommended by KS. And it is recommended that FM of crushed sand should be lowered by improvement of manufacture system or grading adjustment should be used because FM of crushed sand was a bit higher.