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Along with simulated firefighting training, the development of virtual training systems and associated content has recently drawn attention as an alternative method for advanced firefighting training. In particular, to develop virtual training content, it is important to understand the combustion characteristics of indoor combustible materials and appropriately simulate their behavior. In this study, seven types of building fires were selected. From these types, indoor combustible materials of residential buildings were analyzed, and combustion tests were performed for each of three types of combustible materials. Furthermore, three types of indoor spaces, determined according to the combination of indoor combustible materials they contained, were divided into full-scale compartments, and a full-scale fire test was performed using this setup. Finally, the heat release rate and smoke production release of individual combustible materials and the room test were measured over time, and a fire dynamics simulation (FDS) was performed. As a result, it was confirmed that an effective evaluation of the occurrence and spread of fire indoors in buildings is possible through full-scale fire tests and FDS simulations. It is expected that simulation can be used as firefighting training content in the future by applying indoor combustible data and implementing complex and various fire development conditions.
Min-Ho Moon; Hyung-Jun Kim; Su-Gyeong Min; Sung-Chan Kim; Won-Jun Park. Simulation of Indoor Fire Dynamics of Residential Buildings with Full-Scale Fire Test. Sustainability 2021, 13, 4897 .
AMA StyleMin-Ho Moon, Hyung-Jun Kim, Su-Gyeong Min, Sung-Chan Kim, Won-Jun Park. Simulation of Indoor Fire Dynamics of Residential Buildings with Full-Scale Fire Test. Sustainability. 2021; 13 (9):4897.
Chicago/Turabian StyleMin-Ho Moon; Hyung-Jun Kim; Su-Gyeong Min; Sung-Chan Kim; Won-Jun Park. 2021. "Simulation of Indoor Fire Dynamics of Residential Buildings with Full-Scale Fire Test." Sustainability 13, no. 9: 4897.
Numerous factors affect the soil pressure distributions around buried pipes, including the shape, size, and stiffness of the pipe, burial depth, and the stiffness of the surrounding soil. Additionally, to some extent, a pipe can benefit from the soil arching effect, where the overburden and surcharge pressure at the crown can be supported by the adjacent soil. As a result, a buried pipe only needs to support the portion of the load that is not transferred to the adjacent soil. This paper presents numerical investigations of the soil pressure distributions around buried concrete pipes and crack propagation under different environmental conditions, such as loading, saturation level, and the presence of voids. To this end, a nonlinear elastoplastic model for backfill materials was implemented using finite element software and a user-defined subroutine. Three different backfill materials and two different native soils were selected to examine the material-specific behaviors of concrete pipes, including soil pressure distributions and crack propagation. For each backfill material, the effects of the loading type, groundwater, and voids were investigated. These simulation results provide helpful information regarding pressure redistribution and buried concrete pipe behavior under various environmental conditions.
Hoki Ban; Seungjun Roh; Won-Jun Park. Performance Evaluation of Buried Concrete Pipe Considering Soil Pressure and Crack Propagation Using 3D Finite Element Analysis. Applied Sciences 2021, 11, 3292 .
AMA StyleHoki Ban, Seungjun Roh, Won-Jun Park. Performance Evaluation of Buried Concrete Pipe Considering Soil Pressure and Crack Propagation Using 3D Finite Element Analysis. Applied Sciences. 2021; 11 (7):3292.
Chicago/Turabian StyleHoki Ban; Seungjun Roh; Won-Jun Park. 2021. "Performance Evaluation of Buried Concrete Pipe Considering Soil Pressure and Crack Propagation Using 3D Finite Element Analysis." Applied Sciences 11, no. 7: 3292.
This study analyzed the characteristics of the environmental impacts of apartment buildings, a typical housing type in South Korea, as part of a research project supporting the streamlined life cycle assessment (S-LCA) of buildings within the G-SEED (Green Standard for Energy and Environmental Design) framework. Three recently built apartment building complexes were chosen as study objects for the quantitative evaluation of the buildings in terms of their embodied environmental impacts (global warming potential, acidification potential, eutrophication potential, ozone layer depletion potential, photochemical oxidant creation potential, and abiotic depletion potential), using the LCA approach. Additionally, we analyzed the emission trends according to the cut-off criteria of the six environmental impact categories by performing an S-LCA with cut-off criteria 90–99% of the cumulative weight percentile. Consequently, we were able to present the cut-off criterion best suited for S-LCA and analyze the effect of the cut-off criteria on the environmental impact analysis results. A comprehensive environmental impact analysis of the characteristics of the six environmental impact categories revealed that the error rate was below 5% when the cut-off criterion of 97.5% of the cumulative weight percentile was applied, thus verifying its validity as the optimal cut-off criterion for S-LCA.
Rakhyun Kim; Myung-Kwan Lim; Seungjun Roh; Won-Jun Park. Analysis of the Characteristics of Environmental Impacts According to the Cut-Off Criteria Applicable to the Streamlined Life Cycle Assessment (S-LCA) of Apartment Buildings in South Korea. Sustainability 2021, 13, 2898 .
AMA StyleRakhyun Kim, Myung-Kwan Lim, Seungjun Roh, Won-Jun Park. Analysis of the Characteristics of Environmental Impacts According to the Cut-Off Criteria Applicable to the Streamlined Life Cycle Assessment (S-LCA) of Apartment Buildings in South Korea. Sustainability. 2021; 13 (5):2898.
Chicago/Turabian StyleRakhyun Kim; Myung-Kwan Lim; Seungjun Roh; Won-Jun Park. 2021. "Analysis of the Characteristics of Environmental Impacts According to the Cut-Off Criteria Applicable to the Streamlined Life Cycle Assessment (S-LCA) of Apartment Buildings in South Korea." Sustainability 13, no. 5: 2898.
This study aims to compare the potential environmental impact of the manufacture and production of recycled and by-product aggregates based on a life cycle assessment and to evaluate the environmental impact and cost when they are used as aggregates in concrete. To this end, the six potential environmental impacts (i.e., abiotic depletion potential, global warming potential, ozone-layer depletion potential, acidification potential, photochemical ozone creation potential, and eutrophication potential) of the manufacture and production of natural sand, natural gravel, recycled aggregate, slag aggregate, bottom ash aggregate, and waste glass aggregate were compared using information from life cycle inventory databases. Additionally, the environmental impacts and cost were evaluated when these aggregates were used to replace 30% of the fine and coarse aggregates in concrete with a design strength of 24 MPa. The environmental impact of concrete that incorporated slag aggregate as the fine aggregates or bottom ash aggregate as the coarse aggregates were lower than that of concrete that incorporated natural aggregate. However, concrete that incorporated bottom ash aggregate as the fine aggregates demonstrated relatively high environmental impacts. Based on these environmental impacts, the environmental cost was found to range from 5.88 to 8.79 USD/m3.
Seungjun Roh; Rakhyun Kim; Won-Jun Park; Hoki Ban. Environmental Evaluation of Concrete Containing Recycled and By-Product Aggregates Based on Life Cycle Assessment. Applied Sciences 2020, 10, 7503 .
AMA StyleSeungjun Roh, Rakhyun Kim, Won-Jun Park, Hoki Ban. Environmental Evaluation of Concrete Containing Recycled and By-Product Aggregates Based on Life Cycle Assessment. Applied Sciences. 2020; 10 (21):7503.
Chicago/Turabian StyleSeungjun Roh; Rakhyun Kim; Won-Jun Park; Hoki Ban. 2020. "Environmental Evaluation of Concrete Containing Recycled and By-Product Aggregates Based on Life Cycle Assessment." Applied Sciences 10, no. 21: 7503.
The purpose of this study was to identify the major wastes generated during the construction phase using a life cycle assessment. To accomplish this, the amount of waste generated in the construction phase was deduced using the loss rate and weight conversions. Major construction wastes were assessed using six comprehensive environmental impact categories, including global warming potential, abiotic depletion potential, acidification potential, eutrophication potential, ozone depletion potential, and photochemical ozone creation potential. According to the analysis results, five main construction wastes—concrete, rebar, cement, polystyrene panel, and concrete block—comprehensively satisfied the 95% cutoff criteria for all six environmental impact categories. The results of the environmental impact characterization assessment revealed that concrete, concrete block, and cement waste accounted for over 70% of the contribution level in all the environmental impact categories except resource depletion. Insulation materials accounted for 1% of the total waste generated but were identified by the environmental impact assessment to have the highest contribution level.
Won-Jun Park; Rakhyun Kim; Seungjun Roh; Hoki Ban. Identifying the Major Construction Wastes in the Building Construction Phase Based on Life Cycle Assessments. Sustainability 2020, 12, 8096 .
AMA StyleWon-Jun Park, Rakhyun Kim, Seungjun Roh, Hoki Ban. Identifying the Major Construction Wastes in the Building Construction Phase Based on Life Cycle Assessments. Sustainability. 2020; 12 (19):8096.
Chicago/Turabian StyleWon-Jun Park; Rakhyun Kim; Seungjun Roh; Hoki Ban. 2020. "Identifying the Major Construction Wastes in the Building Construction Phase Based on Life Cycle Assessments." Sustainability 12, no. 19: 8096.
Recently, artificial intelligence (AI) technologies have been employed to predict construction and demolition (C&D) waste generation. However, most studies have used machine learning models with continuous data input variables, applying algorithms, such as artificial neural networks, adaptive neuro-fuzzy inference systems, support vector machines, linear regression analysis, decision trees, and genetic algorithms. Therefore, machine learning algorithms may not perform as well when applied to categorical data. This article uses machine learning algorithms to predict C&D waste generation from a dataset, as a way to improve the accuracy of waste management in C&D facilities. These datasets include categorical (e.g., region, building structure, building use, wall material, and roofing material), and continuous data (particularly, gloss floor area), and a random forest (RF) algorithm was used. Results indicate that RF is an adequate machine learning algorithm for a small dataset consisting of categorical data, and even with a small dataset, an adequate prediction model can be developed. Despite the small dataset, the predictive performance according to the demolition waste (DW) type was R (Pearson’s correlation coefficient) = 0.691–0.871, R2 (coefficient of determination) = 0.554–0.800, showing stable prediction performance. High prediction performance was observed using three (for mortar), five (for other DW types), or six (for concrete) input variables. This study is significant because the proposed RF model can predict DW generation using a small amount of data. Additionally, it demonstrates the possibility of applying AI to multi-purpose DW management.
Gi-Wook Cha; Hyeun Jun Moon; Young-Min Kim; Won-Hwa Hong; Jung-Ha Hwang; Won-Jun Park; Young-Chan Kim. Development of a Prediction Model for Demolition Waste Generation Using a Random Forest Algorithm Based on Small DataSets. International Journal of Environmental Research and Public Health 2020, 17, 6997 .
AMA StyleGi-Wook Cha, Hyeun Jun Moon, Young-Min Kim, Won-Hwa Hong, Jung-Ha Hwang, Won-Jun Park, Young-Chan Kim. Development of a Prediction Model for Demolition Waste Generation Using a Random Forest Algorithm Based on Small DataSets. International Journal of Environmental Research and Public Health. 2020; 17 (19):6997.
Chicago/Turabian StyleGi-Wook Cha; Hyeun Jun Moon; Young-Min Kim; Won-Hwa Hong; Jung-Ha Hwang; Won-Jun Park; Young-Chan Kim. 2020. "Development of a Prediction Model for Demolition Waste Generation Using a Random Forest Algorithm Based on Small DataSets." International Journal of Environmental Research and Public Health 17, no. 19: 6997.
To address the environmental problems associated with construction materials, the construction industry has made considerable efforts to reduce carbon emissions. However, construction materials cause several other environmental problems in addition to carbon emissions and thus, a comprehensive analysis of environmental impact categories is required. This study aims to determine the major environmental impact categories for each construction material in production stage using the life cycle assessment (LCA) technique on road projects. Through the review of life cycle impact assessment (LCIA) methodologies, the abiotic depletion potential (ADP), ozone depletion potential, photochemical oxidant creation potential, acidification potential, eutrophication potential, eco-toxicity potential, human toxicity potential, as well as the global warming potential (GWP) were defined as impact categories. To define the impact categories for road construction materials, major environmental pollutants were analyzed for a number of road projects, and impact categories for 13 major construction materials were selected as mandatory impact categories. These materials contributed more than 80% to the impact categories from an LCA perspective. The impact categories to which each material contributed more than 99% were proposed as specialization impact categories to provide basic data for use in the LCIA of future road projects.
Won-Jun Park; Rakhyun Kim; Seungjun Roh; Hoki Ban. Analysis of Major Environmental Impact Categories of Road Construction Materials. Sustainability 2020, 12, 6951 .
AMA StyleWon-Jun Park, Rakhyun Kim, Seungjun Roh, Hoki Ban. Analysis of Major Environmental Impact Categories of Road Construction Materials. Sustainability. 2020; 12 (17):6951.
Chicago/Turabian StyleWon-Jun Park; Rakhyun Kim; Seungjun Roh; Hoki Ban. 2020. "Analysis of Major Environmental Impact Categories of Road Construction Materials." Sustainability 12, no. 17: 6951.
Existing deicing technologies involving chloride and heating wires have limitations such as reduced durability of roads and surrounding structures, and high labor requirements and maintenance costs. Hence, in this study, we performed indoor experiments, numerical analyses, and field tests to examine the efficiency of deicing using carbon nanotubes (CNTs) to overcome these limitations. For indoor experiments, a CNT was inserted into the center of a concrete sample and then heated to 60 °C while maintaining the ambient and internal temperatures of the sample at −10 °C using a refrigeration chamber. Numerical analysis considering thermal conductivity was performed based on the indoor experimental results. Using the calculation results, field tests were conducted, and the thermal conduction performance of the heating element was examined. Results showed that the surface temperature between the heating elements exceeded 0 °C. Moreover, we found that the effective heating distance of the heating elements should be 20–30 cm for effective thermal overlap through the indoor experiments. Additionally, the numerical analysis results indicated that the effective heating distance increased to 100 cm when the heating element temperature and experiment time were increased. Field test results showed that 62 cm-deep snow melted between the heating elements (100 cm), thus, verifying the possibility of deicing.
Hee Su Kim; Hoki Ban; Won-Jun Park. Deicing Concrete Pavements and Roads with Carbon Nanotubes (CNTs) as Heating Elements. Materials 2020, 13, 2504 .
AMA StyleHee Su Kim, Hoki Ban, Won-Jun Park. Deicing Concrete Pavements and Roads with Carbon Nanotubes (CNTs) as Heating Elements. Materials. 2020; 13 (11):2504.
Chicago/Turabian StyleHee Su Kim; Hoki Ban; Won-Jun Park. 2020. "Deicing Concrete Pavements and Roads with Carbon Nanotubes (CNTs) as Heating Elements." Materials 13, no. 11: 2504.
In multi-arch tunnels, the increased rock load on the concrete lining of the main tunnel and side walls due to the excavation of adjacent tunnels is critical and must be considered in the design stage. Therefore, this study estimates the rock load of a multi-arch tunnel using two-dimensional numerical analysis, considering rock mass classifications, overburden, and construction steps. The rock load is estimated using two criteria: the factor of safety and stress variable. The rock load is underestimated when the factor of safety is applied to rock mass class III. However, the stress variable method reveals a reasonable rock load as overburden increases. Particularly, the rock load is estimated to be equal to the overburden in shallow tunnels and approximately 0.7 times the tunnel width in deep tunnels. Additionally, the crack-induced rock load is computed using back analysis at the excavation completion stage of adjacent tunnels, yielding the relation between the rock load height and the deformation modulus of the rock mass. Therefore, an accurate estimation of the rock load of multi-arch tunnels emphasizes the importance of a more economical and realistic design and must be addressed in the process of performance-based tunnel design.
Jae Kook Lee; Hankyu Yoo; Hoki Ban; Won-Jun Park. Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method. Applied Sciences 2020, 10, 3285 .
AMA StyleJae Kook Lee, Hankyu Yoo, Hoki Ban, Won-Jun Park. Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method. Applied Sciences. 2020; 10 (9):3285.
Chicago/Turabian StyleJae Kook Lee; Hankyu Yoo; Hoki Ban; Won-Jun Park. 2020. "Estimation of Rock Load of Multi-Arch Tunnel with Cracks Using Stress Variable Method." Applied Sciences 10, no. 9: 3285.
In the case of fire, surface treatment agents used in external insulation finishing methods are substances that are vulnerable to fire. This study examined the incorporation and applicability of expandable graphite in surface preparation mortar so that heat transfer to the surface part can be suppressed even when the cementitious surface preparation mortar is thinly constructed in the external insulation method. Experimental results showed that the mechanical properties of surface preparation mortar were improved by using the fly ash and silica fume. Surface treatment materials using expanded graphite have a characteristic of expanding when a fire occurs. It was experimentally confirmed that incorporating expanded graphite can reduce the phenomenon of heat penetration to the rear surface when the surface preparation mortar is exposed to high temperatures such as a flame.
Sung-Young Song; Hwa-Sung Ryu; Sang-Heon Shin; Deuck-Mo Kim; And Won-Jun Park. Properties of External Insulation Surface Preparation Mortar Using Expandable Graphite for Fire Resistance. Sustainability 2019, 11, 6882 .
AMA StyleSung-Young Song, Hwa-Sung Ryu, Sang-Heon Shin, Deuck-Mo Kim, And Won-Jun Park. Properties of External Insulation Surface Preparation Mortar Using Expandable Graphite for Fire Resistance. Sustainability. 2019; 11 (23):6882.
Chicago/Turabian StyleSung-Young Song; Hwa-Sung Ryu; Sang-Heon Shin; Deuck-Mo Kim; And Won-Jun Park. 2019. "Properties of External Insulation Surface Preparation Mortar Using Expandable Graphite for Fire Resistance." Sustainability 11, no. 23: 6882.
The waste generation rate (WGR) is used to predict the generation of construction and demolition waste (C&DW) and has become a prevalent tool for efficient waste management systems. Many studies have focused on deriving the WGR, but most focused on demolition waste rather than construction waste (CW). Moreover, previous studies have used theoretical databases and thus were limited in showing changes in the generated CW during the construction period of actual sites. In this study, CW data were collected for recently completed apartment building sites through direct measurement, and the WGR was calculated by CW type for the construction period. The CW generation characteristics by type were analyzed, and the results were compared with those of previous studies. In this study, CW was classified into six types: Waste concrete, waste asphalt concrete, waste wood, waste synthetic resin, waste board, and mixed waste. The amount of CW generated was lowest at the beginning of the construction period. It slowly increased over time and then decreased again at the end. In particular, waste concrete and mixed waste were generated throughout the construction period, while other CWs were generated in the middle of the construction period or towards the end. The research method and results of this study are significant in that the construction period was considered, which has been neglected in previous studies on the WGR. These findings are expected to contribute to the development of efficient CW management systems.
Young-Chan Kim; Yuan-Long Zhang; Won-Jun Park; Gi-Wook Cha; Jung-Wan Kim; Won-Hwa Hong. Analysis of Waste Generation Characteristics during New Apartment Construction—Considering the Construction Phase. International Journal of Environmental Research and Public Health 2019, 16, 3485 .
AMA StyleYoung-Chan Kim, Yuan-Long Zhang, Won-Jun Park, Gi-Wook Cha, Jung-Wan Kim, Won-Hwa Hong. Analysis of Waste Generation Characteristics during New Apartment Construction—Considering the Construction Phase. International Journal of Environmental Research and Public Health. 2019; 16 (18):3485.
Chicago/Turabian StyleYoung-Chan Kim; Yuan-Long Zhang; Won-Jun Park; Gi-Wook Cha; Jung-Wan Kim; Won-Hwa Hong. 2019. "Analysis of Waste Generation Characteristics during New Apartment Construction—Considering the Construction Phase." International Journal of Environmental Research and Public Health 16, no. 18: 3485.
In this study, the porosity assessment of bonded mortar of recycled aggregates (RA) is done by backscattered electron (BSE) image analysis, for the first time. The resulting effect on concrete mechanical properties was determined as well. Different mixes of recycled aggregate concrete (RAC) were formulated. The concrete specimens were cast to determine the compressive strength at various ages. Later, after 28 – day age, the hardened concrete specimens were used to extract samples for BSE image analysis. The BSE analysis was done by using the pore segmentation method previously developed to ascertain the microstructural features of hydrated cement pastes. From the image analysis, plots of segmented area versus grey value and brightness histograms at different threshold levels were obtained. The BSE image analysis was used to determine the pore area and total area in each frame for porosity assessment. The results indicated that RA affect the resulting mechanical strength of hardened concrete due to the lower specific gravity and higher water absorption as compared to the natural aggregates (NA). Recycled coarse aggregate (RCA) has about 28% higher bonded mortar content (BMC) with porosity of bonded mortar (BM) almost double as that of recycled fine aggregate (RFA). This leads to inferior interface between aggregate and cement paste thereby affecting the overall concrete properties. It is suggested to use pre-treatment methods for surface modification of RA for efficient use in eco-friendly and sustainable construction.
Yongjae Kim; Asad Hanif; Muhammad Usman; Wonjun Park. Influence of bonded mortar of recycled concrete aggregates on interfacial characteristics – Porosity assessment based on pore segmentation from backscattered electron image analysis. Construction and Building Materials 2019, 212, 149 -163.
AMA StyleYongjae Kim, Asad Hanif, Muhammad Usman, Wonjun Park. Influence of bonded mortar of recycled concrete aggregates on interfacial characteristics – Porosity assessment based on pore segmentation from backscattered electron image analysis. Construction and Building Materials. 2019; 212 ():149-163.
Chicago/Turabian StyleYongjae Kim; Asad Hanif; Muhammad Usman; Wonjun Park. 2019. "Influence of bonded mortar of recycled concrete aggregates on interfacial characteristics – Porosity assessment based on pore segmentation from backscattered electron image analysis." Construction and Building Materials 212, no. : 149-163.
This study assessed the influence of matter discharged during the production (dry/wet) of recycled aggregate on global warming potential (GWP) and acidification potential (AP), eutrophication potential (EP), ozone depletion potential (ODP), biotic resource depletion potential (ADP), photochemical ozone creation potential (POCP) using the ISO 14044 (LCA) standard. The LCIA of dry recycled aggregate was 2.94 × 10−2 kg-CO2eq/kg, 2.93 × 10−5 kg-SO2eq/kg, 5.44 × 10−6 kg-PO43eq/kg, 4.70 × 10−10 kg-CFC11eq/kg, 1.25 × 10−5 kg-C2H4eq/kg, and 1.60 × 10−5 kg-Antimonyeq/kg, respectively. The environmental impact of recycled aggregate (wet) was up to 16~40% higher compared with recycled aggregate (dry); the amount of energy used by impact crushers while producing wet recycled aggregate was the main cause for this result. The environmental impact of using recycled aggregate was found to be up to twice as high as that of using natural aggregate, largely due to the greater simplicity of production of natural aggregate requiring less energy. However, ADP was approximately 20 times higher in the use of natural aggregate because doing so depletes natural resources, whereas recycled aggregate is recycled from existing construction waste. Among the life cycle impacts assessment of recycled aggregate, GWP was lower than for artificial light-weight aggregate but greater than for slag aggregate.
Won-Jun Park; TaeHyoung Kim; Seungjun Roh; Rakhyun Kim. Analysis of Life Cycle Environmental Impact of Recycled Aggregate. Applied Sciences 2019, 9, 1021 .
AMA StyleWon-Jun Park, TaeHyoung Kim, Seungjun Roh, Rakhyun Kim. Analysis of Life Cycle Environmental Impact of Recycled Aggregate. Applied Sciences. 2019; 9 (5):1021.
Chicago/Turabian StyleWon-Jun Park; TaeHyoung Kim; Seungjun Roh; Rakhyun Kim. 2019. "Analysis of Life Cycle Environmental Impact of Recycled Aggregate." Applied Sciences 9, no. 5: 1021.
One of the various methods of manufacturing low-carbon cement is substituting limestone powder as a raw material or admixture. Limestone sludge powder (LSSP) has the same composition as that of limestone powder. The surface characteristics of LSSP powder modified with recycled acetic acid (RAA) and the characteristics of cement using this modified LSSP as a substitute were investigated in this study. The surface of LSSP modified with RAA was converted into calcium acetate and had a large grain size. When conventional LSSP was used as a substitute for cement, the initial strength increased owing to improved pore filling; however, the strength after 28 days of aging was lower than that of non-substituted cement. In the case of modified LSSP being replaced with cement at up to 10% of the cement weight, however, the calcium acetate on its surface increased the amount of hydration products in the cement, thereby increasing both the initial and the long-term strength.
Hwa-Sung Ryu; Deuck-Mo Kim; Sang-Heon Shin; Wan-Ki Kim; Seung-Min Lim; Won-Jun Park. Properties of Cement Mortar Using Limestone Sludge Powder Modified with Recycled Acetic Acid. Sustainability 2019, 11, 879 .
AMA StyleHwa-Sung Ryu, Deuck-Mo Kim, Sang-Heon Shin, Wan-Ki Kim, Seung-Min Lim, Won-Jun Park. Properties of Cement Mortar Using Limestone Sludge Powder Modified with Recycled Acetic Acid. Sustainability. 2019; 11 (3):879.
Chicago/Turabian StyleHwa-Sung Ryu; Deuck-Mo Kim; Sang-Heon Shin; Wan-Ki Kim; Seung-Min Lim; Won-Jun Park. 2019. "Properties of Cement Mortar Using Limestone Sludge Powder Modified with Recycled Acetic Acid." Sustainability 11, no. 3: 879.
A polymer-modified cement mortar (PCM) is widely used as a repair material for reinforced concrete (RC) structures owing to its excellent strength and durability. However, considering the maintenance of the RC structures and the use period of the structures, the change in the physical properties of the PCM should be evaluated when exposed to various high-temperature environments, such as fires. In this study, the degradation of the mechanical properties (compressive strength and modulus of elasticity), thermal decomposition of the PCM in various high-temperature environments, and the change in the pore structure of the PCM after exposure to high temperatures were quantitatively investigated. A mechanical property evaluation of PCM was performed under three heating conditions: (i) heating in a compression tester, (ii) heating the specimen in an oven to a predetermined temperature and then moving it to a compression tester preheated to the same temperature, and (iii) cooling to room temperature after heating. In the experiment, a PCM specimen was prepared by changing the polymer–cement ratio (polymer content) of ethylene-vinyl acetate (EVA), the most commonly used polymer, to perform a high-temperature sectional test from 200 to 800 °C. In addition, to investigate the change in the PCM mechanical properties in the high-temperature region, in terms of the pyrolysis of EVA, the porosity change and mass change were examined using thermal analysis and mercury intrusion porosimetry. Before heating, the compressive strength of the PCM increased with the EVA content up to 10 % of the polymer–cement ratio. Under the cooling conditions after heating up to 200 °C, the mechanical performance of the PCM was restored, whereas the degradation of the mechanical properties of the PCM without cooling was more pronounced. Furthermore, the mass loss, heat flow, and the total porosity of the PCM increased as the EVA content increased, which is correlated with the degradation of the mechanical properties of the PCM.
Hyung-Jun Kim; Jae-Yeon Park; Heong-Won Suh; Beom-Yeon Cho; Won-Jun Park; Sung-Chul Bae. Mechanical Degradation and Thermal Decomposition of Ethylene-Vinyl Acetate (EVA) Polymer-Modified Cement Mortar (PCM) Exposed to High-Temperature. Sustainability 2019, 11, 500 .
AMA StyleHyung-Jun Kim, Jae-Yeon Park, Heong-Won Suh, Beom-Yeon Cho, Won-Jun Park, Sung-Chul Bae. Mechanical Degradation and Thermal Decomposition of Ethylene-Vinyl Acetate (EVA) Polymer-Modified Cement Mortar (PCM) Exposed to High-Temperature. Sustainability. 2019; 11 (2):500.
Chicago/Turabian StyleHyung-Jun Kim; Jae-Yeon Park; Heong-Won Suh; Beom-Yeon Cho; Won-Jun Park; Sung-Chul Bae. 2019. "Mechanical Degradation and Thermal Decomposition of Ethylene-Vinyl Acetate (EVA) Polymer-Modified Cement Mortar (PCM) Exposed to High-Temperature." Sustainability 11, no. 2: 500.
Ready mixed acrylic paste (RMAP) is a material used in exterior insulation systems of buildings; it consists of liquids and aggregates. However, it is considerably difficult to use an admixture to control the physical properties of the RMAP owing to problems associated with strength and workability. Thus, to improve the properties of RMAP, this study evaluates the properties of a mortar produced with RMAP as well as pozzolanic materials and atomizing slag, which is a by-product from the steelmaking industry. It was observed that if the density difference is large, a liquid RMAP may experience segregation. Through our experiments, we confirm that segregation resistance could be achieved even at 20% atomizing slag, which has a high density, by increasing the viscosity by approximately 1000 cP through the use of 10% fly ash and 3% metakaolin in the RMAP. Despite the increase in viscosity with the addition of the atomizing slag, the flow of the RMAP increased from 160 to 175 mm due to the spherical particle shape of the slag; in addition, the strength and water absorption coefficient also improved. In particular, the adhesion tension increased from 1.8 N/mm2 to 2.4 N/mm2 or higher.
Sung-Yong Song; Hwa-Sung Ryu; Sang-Heon Shin; Deuck-Mo Kim; Won-Jun Park. Properties of Ready Mixed Acrylic Paste for Exterior Insulation Using Pozzolanic Materials and Atomizing Slag. Advances in Materials Science and Engineering 2018, 2018, 1 -12.
AMA StyleSung-Yong Song, Hwa-Sung Ryu, Sang-Heon Shin, Deuck-Mo Kim, Won-Jun Park. Properties of Ready Mixed Acrylic Paste for Exterior Insulation Using Pozzolanic Materials and Atomizing Slag. Advances in Materials Science and Engineering. 2018; 2018 ():1-12.
Chicago/Turabian StyleSung-Yong Song; Hwa-Sung Ryu; Sang-Heon Shin; Deuck-Mo Kim; Won-Jun Park. 2018. "Properties of Ready Mixed Acrylic Paste for Exterior Insulation Using Pozzolanic Materials and Atomizing Slag." Advances in Materials Science and Engineering 2018, no. : 1-12.
With an increase in the number of Green Standard for Energy and Environmental Design (G-SEED)-certified apartments in South Korea, people are receiving incentives from the government to purchase them. Since 2013, many benefits for G-SEED-certified buildings have been offered, such as tax reductions and deregulation of building codes/guidelines. As beneficial incentives are granted to G-SEED-certified buildings, follow-up management of the buildings is also necessary. However, to date, there are no appropriate follow-up management systems or legal regulations for G-SEED-certified buildings. Buildings that are certified by G-SEED in Korean housing buildings account for 6.25% of Korea’s total area. In addition, G-SEED certification has been obtained for more than 20% of the total completed housing area (2014–2017). Therefore, the energy efficiency-management of G-SEED certified buildings is also very important economically for reducing greenhouse gas emissions. In this study, domestic and foreign energy efficiency follow-up management systems were analyzed, and the amount of energy that is used by apartment houses with incentives was investigated. We have identified problems with the G-SEED system by analyzing evaluation methods, evaluation items, and points of G-SEED certification in related research studies. We also compared the energy consumption of an apartment building with G-SEED certification with that of adjacent complexes, thereby applying original research methods. The results show that energy use in G-SEED-certified buildings was not efficient. Accordingly, the study confirms that continuous management after G-SEED certification by establishing a follow-up management system is needed. In this study, domestic and foreign follow-up management systems were compared, problems with the apartment housing information management system run by the government were examined, and improvement measures were suggested.
Hyemi Kim; Wonjun Park. A Study of the Energy Efficiency Management in Green Standard for Energy and Environmental Design (G-SEED)-Certified Apartments in South Korea. Sustainability 2018, 10, 3402 .
AMA StyleHyemi Kim, Wonjun Park. A Study of the Energy Efficiency Management in Green Standard for Energy and Environmental Design (G-SEED)-Certified Apartments in South Korea. Sustainability. 2018; 10 (10):3402.
Chicago/Turabian StyleHyemi Kim; Wonjun Park. 2018. "A Study of the Energy Efficiency Management in Green Standard for Energy and Environmental Design (G-SEED)-Certified Apartments in South Korea." Sustainability 10, no. 10: 3402.
Regulating energy consumption can reduce both greenhouse gas emissions and expenditures. In order to maximize efficiency, appropriate energy protocols for buildings must be devised and implemented. This study examines predicted and real energy savings, the differences between them, and the methods which might reduce these discrepancies. Analyses for 195 high-efficiency apartment units (certified based on the energy efficiency rating system in use in Korea) indicated an average difference of 23% between predicted and real energy savings. This was found to be due to the fact that predictions failed to take variables such as Heating Type, Corridor Type, and Climate into account. By accounting for these factors, an appropriate calculation formula may be established. Using the revised calculation formula to reevaluate the predicted energy savings of 13 apartment units resulted in a reduction of 7% in the aforementioned discrepancy between predicted and real energy savings. Using the proposed formula to predict energy savings in buildings could improve accuracy, thus facilitating the setting of appropriate standards for restrictions on greenhouse gas emissions of buildings.
Won-Jun Park; Hye-Mi Kim. Study on the Improvement of Expected Energy Savings and Actual Energy Savings in Apartments. Sustainability 2018, 10, 1089 .
AMA StyleWon-Jun Park, Hye-Mi Kim. Study on the Improvement of Expected Energy Savings and Actual Energy Savings in Apartments. Sustainability. 2018; 10 (4):1089.
Chicago/Turabian StyleWon-Jun Park; Hye-Mi Kim. 2018. "Study on the Improvement of Expected Energy Savings and Actual Energy Savings in Apartments." Sustainability 10, no. 4: 1089.
Recycled aggregates (RAs) production techniques are essential for the material circulation society because RAs from demolished concrete waste can sustainably be reused as a concrete material. However, RAs can bring about several performance decreases when they are used for recycled aggregate concrete (RAC) because of the low qualities (i.e., high water-absorption rate and low density) caused by the attached hydrated cement paste on the RA surface. Therefore, both the production of high-quality RAs and the surface modification of RAs are significantly important for the extension of RAC utilization. This paper focuses on the surface modification of RFA to reduce the water absorption rate and increase density. Hydrofluorosilicic acid (H2SiF6), which is one of the by-products in phosphoric acid manufacture, is used herein for the surface modification of the RFA. The physical properties and mechanical performance of mortar using RFA were evaluated after RFA modification. Consequently, the proposed method is effective in reducing water absorption rate and increasing density of RFA. The density of RFAs was slightly increased by 0.5–2.6% after modification. On the other hand, the water absorption rate decreased by 4–18% after modification. The compressive strengths of mortar at 28 days ages showed 18.1 MPa with modified RFA and 16.2 MPa with RFA.
Hwa-Sung Ryu; Deuck-Mo Kim; Sang-Heon Shin; Seung-Min Lim; Won-Jun Park. Evaluation on the Surface Modification of Recycled Fine Aggregates in Aqueous H2SiF6 Solution. International Journal of Concrete Structures and Materials 2018, 12, 19 .
AMA StyleHwa-Sung Ryu, Deuck-Mo Kim, Sang-Heon Shin, Seung-Min Lim, Won-Jun Park. Evaluation on the Surface Modification of Recycled Fine Aggregates in Aqueous H2SiF6 Solution. International Journal of Concrete Structures and Materials. 2018; 12 (1):19.
Chicago/Turabian StyleHwa-Sung Ryu; Deuck-Mo Kim; Sang-Heon Shin; Seung-Min Lim; Won-Jun Park. 2018. "Evaluation on the Surface Modification of Recycled Fine Aggregates in Aqueous H2SiF6 Solution." International Journal of Concrete Structures and Materials 12, no. 1: 19.
Calcium acetate, which can be used in concrete to shorten the construction period and to improve productivity, was manufactured using limestone sludge and acetic acid. Calcium acetate contains a carboxyl group, and it can provide anticorrosive properties by forming a complex with the steel surface. We evaluated the basic performance of a carboxylic early-strength agent produced from industrial by-products (limestone sludge and acetic acid) as a corrosion inhibitor. A comparative evaluation was performed using calcium nitrate, which is a conventional early-strength agent; the corrosion area ratio, corrosion state, and electrochemical performance of a steel plate immersed in aqueous solutions were evaluated. A steel plate immersed in calcium acetate was not substantially corroded. The electrochemical investigations showed a high corrosion potential based on the impedance characteristics. The corrosion current showed anodic values, and no corrosion occurred on the surface of the steel plate because of the adsorption of carboxyl groups. Scanning electron microscopy indicated that the steel plate was covered by a crystalline coating, which suppressed corrosion. We show that it is possible to develop an environmentally friendly recycling method as an early-strength agent and corrosion inhibitor when manufacturing calcium acetate using limestone sludge.
Hwa-Sung Ryu; Deuck-Mo Kim; Sang-Heon Shin; Won-Jun Park; Seung-Jun Kwon. Steel-Corrosion Characteristics of an Environmental Inhibitor using Limestone Sludge and Acetic Acid. International Journal of Concrete Structures and Materials 2018, 12, 13 .
AMA StyleHwa-Sung Ryu, Deuck-Mo Kim, Sang-Heon Shin, Won-Jun Park, Seung-Jun Kwon. Steel-Corrosion Characteristics of an Environmental Inhibitor using Limestone Sludge and Acetic Acid. International Journal of Concrete Structures and Materials. 2018; 12 (1):13.
Chicago/Turabian StyleHwa-Sung Ryu; Deuck-Mo Kim; Sang-Heon Shin; Won-Jun Park; Seung-Jun Kwon. 2018. "Steel-Corrosion Characteristics of an Environmental Inhibitor using Limestone Sludge and Acetic Acid." International Journal of Concrete Structures and Materials 12, no. 1: 13.