http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Investigation of Coal Ash in Roadway Backfill Material
Tri Ho Minh Le,Dae-Wook Park,Jung-Woo Seo,Jun Kim 한국도로학회 2018 한국도로학회 학술대회 발표논문 초록집 Vol.2018 No.05
This research evaluates the applicability of ponded ash in the production of backfill material. From various ponded ash/sand ratios, cement, and air foam conditions, test specimens were developed to investigate many engineer properties of backfill material. Then, the falling weight deflectometer and excavation tests were carried out to determine the behavior of the material in the actual testbed. The test results suggested that all mixtures achieved optimal flowability performance with acceptable stiffening time. It is indicated that the compressive strength increased as ponded ash and cement contents increased, but the strength decreased with an increase in air-foam content or number of freeze-thaw cycles. From the testbed results, it was found that utilizing 100% ponded ash in the production of backfill material is very promising for sustainable development purpose.
Le, Tri Ho Minh,Park, Dae-Wook,Seo, Jung-Woo Elsevier 2019 Construction and Building Materials Vol.206 No.-
<P><B>Abstract</B></P> <P>A new cement asphalt mortar (CAM) stabilized ballast method is expected to reinforce the ballast layer by improving the ballast structural durability with short construction time. In this work, the effect of quick-hardening admixture (QA), and sand on the mechanical performance of CAM are mainly discussed. The test results verified that sand particles behave as an interlayer between the cement particles and asphalt droplets which enhances the mixing stability remarkably. Adding QA not only eliminated the bleeding problem, controlled the workability of the mixture but also contributed to the fast strength development of the mixture.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sand behaves as an interlayer that improves the mixing stability of asphalt emulsion. </LI> <LI> Quick-hardening admixture provides fast strength gain with no sign of bleeding. </LI> <LI> The increase in asphalt emulsion leads to a significant drop in compressive strength. </LI> <LI> All cement asphalt mortar shows ductile behavior after reaching the peak stress. </LI> </UL> </P>
LE, Thai Thanh Dat,HO, Thi Thanh Ngan,LE, Nguyen Truc Quyen,HUYNH, Thi Khanh Tuyen,NGUYEN, Minh Tri,LUU, Thi Mai Anh,HOANG, Thi Phuong Thao,NGUYEN, Trong Luan Korea Distribution Science Association 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.6
The purpose of the study is to analyze the significant impacts of expectations, performance, complaints, and fairness that affect consumer satisfaction. The methodology involves reviewing and referencing relevant literature carefully, then proposing a model for customer satisfaction. This study is empirically based on a survey with 50 respondents who work in the field of import and export in the region stretching from the north to the south of Vietnam. The sampling method used in this study is the in-depth interview method. The results show that: (1) expectation has a specific impact on customer satisfaction, (2) performance has a positive impact on customer satisfaction, and (3) complaint which is an intermediary factor between expectation, performance, and fairness has an impact on satisfaction, (4) fairness has a positive effect on satisfaction, in addition, fairness is an extremely important feature when customers choose an import-export service. Research implies that increasing expectations, performance, and fairness results in an improved customer experience and satisfaction when they use the service. It is suggested that the complaint factor continue to be studied and looked into because it still has some effect on satisfaction and is an intermediate variable that changes how the other factors relate to each other.
Effect of Steel Slag on Self-healing Performance of Asphalt Concrete Using Microwave Technique
Tam Minh Phan,Dae-Wook Park,Tri Ho Minh Le,Namyu Kim,Allistair Bliss Tam 한국도로학회 2018 한국도로학회 학술대회 발표논문 초록집 Vol.2018 No.05
This paper evaluates the affection of steel slag in the asphalt mixtures for the self-healing purpose through microwave heating technique. Four different contents of steel wool fibers (SWF) were developed in hot mix asphalt and two types of aggregate were used: steel slag aggregate and normal aggregate. By using the infrared camera, the thermal distribution, as well as the optimum healing time of test samples, were recorded. All mixtures were evaluated their healing performance throughout 8 cycles. The substitution of about 30% normal coarse aggregate by steel slag is prominent due to its effect not only produces better healing performance but also enhances the whole mixture improve load-displacement trend with higher ductile behavior. The application of steel slag in HMA is a promising method which contributes toward the sustainable roadway development.