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Incineration bottom ash is generated by the incineration of solid waste. Household solid waste is increasing every year and so is incineration bottom ash. This is a problem to treat the incineration bottom ash because the ash has many toxic components. Cement composites can solve this problem and there are many studies for using the bottom ash as fine aggregate. To evaluate the usage of incineration bottom ash, compressive strength, mercury intrusion porosimetry, scanning electron microscopy-backscatter electron, X-ray diffraction, and toxicity characteristic leaching processes were performed. When using incineration bottom ash up to 20% of substitution, the compressive strength in all cases was increased. This study showed how the filler effect appeared well in the cement composites through the scanning electron microscopy-backscatter electron, and mercury intrusion porosimetry. X-ray diffraction indicated the possibility of an alkali-silica reaction of the aggregate with the components of incineration bottom ash. This problem is an obstacle to applying the incineration bottom ash as a fine aggregate. In addition, the toxicity characteristic leaching process was shown to be under the threshold of the Korean standard, however, this should nuanced by the consideration of amorphity. Comprehensively, incineration bottom ash could be used as a fine aggregate of up to 20% of substitution. However, the pre-treatment would need to eliminate or reduce alkali reactive components and heavy metals.
Byeong-Hun Woo; In-Kyu Jeon; Dong-Ho Yoo; Seong-Soo Kim; Jeong-Bae Lee; Hong-Gi Kim. Utilization of Municipal Solid Waste Incineration Bottom Ash as Fine Aggregate of Cement Mortars. Sustainability 2021, 13, 8832 .
AMA StyleByeong-Hun Woo, In-Kyu Jeon, Dong-Ho Yoo, Seong-Soo Kim, Jeong-Bae Lee, Hong-Gi Kim. Utilization of Municipal Solid Waste Incineration Bottom Ash as Fine Aggregate of Cement Mortars. Sustainability. 2021; 13 (16):8832.
Chicago/Turabian StyleByeong-Hun Woo; In-Kyu Jeon; Dong-Ho Yoo; Seong-Soo Kim; Jeong-Bae Lee; Hong-Gi Kim. 2021. "Utilization of Municipal Solid Waste Incineration Bottom Ash as Fine Aggregate of Cement Mortars." Sustainability 13, no. 16: 8832.
To solve the problem of black ice, many studies are being carried out. The key in recent days is enhancing the thermal conductivity of concrete. In this study, to improve the thermal conductivity, silicon carbide was used to substitute 50% and 100% of the fine aggregate. In addition, steel fiber is not only for enhancing the mechanical properties but could enhance thermal conductive material. Hence, the arched-type steel fiber was used up to a 1% volume fraction in this study. Furthermore, graphite was used for 5% of the volume fraction for enhancing the thermal conductivity. However, thermal damage would occur due to the difference in thermal conductivity between materials. Therefore, the thermal durability must be verified first. The target application of the concrete in this study was its use as road paving material. To evaluate the thermal durability, freeze–thaw and rapid cyclic thermal attacks were performed. The thermal conductivity of the specimens was increased with the increase in thermal conductive materials. Graphite has already been reported to have a negative effect on mechanical properties, and the results showed that this was the case. However, the steel fiber compensated for the negative effect of graphite, and the silicon carbide provided a filler effect. Graphite also had a negative effect on the freeze–thaw and rapid cyclic thermal attack, but the steel fiber compensated for the reduction in thermal durability. The silicon carbide also helped to improve the thermal durability in the same way as steel fiber. Comprehensively, the steel fiber enhanced all of the properties of the tests. Using 100% silicon carbide was considered the acceptable range, but 50% of silicon carbide was the best. Graphite decreased all the properties except for the thermal conductivity. Therefore, the content of graphite or using other conductive materials used should be carefully considered in further studies.
Byeong-Hun Woo; Dong-Ho Yoo; Seong-Soo Kim; Jeong-Bae Lee; Jae-Suk Ryou; Hong-Gi Kim. Effects of Thermal Conductive Materials on the Freeze-Thaw Resistance of Concrete. Materials 2021, 14, 4063 .
AMA StyleByeong-Hun Woo, Dong-Ho Yoo, Seong-Soo Kim, Jeong-Bae Lee, Jae-Suk Ryou, Hong-Gi Kim. Effects of Thermal Conductive Materials on the Freeze-Thaw Resistance of Concrete. Materials. 2021; 14 (15):4063.
Chicago/Turabian StyleByeong-Hun Woo; Dong-Ho Yoo; Seong-Soo Kim; Jeong-Bae Lee; Jae-Suk Ryou; Hong-Gi Kim. 2021. "Effects of Thermal Conductive Materials on the Freeze-Thaw Resistance of Concrete." Materials 14, no. 15: 4063.
In this study, light-burnt dolomite powder was substituted for up to 20% of ground granulated blast-furnace slag in sodium sulfate-activated slag systems. The effects of light-burnt dolomite incorporation on compressive strength were investigated. Mineralogical analysis included XRD and FT-IR. Microstructure analysis included MIP and SEM examination. The durability properties, including carbonation depth and chloride penetration, were also investigated. The results indicate that the inclusion of LBD enhanced hydrotalcite and calcite formation and resulted in dense microstructures. All specimens with LBD had better mechanical and durability properties than did mixtures without LBD. Compared with 10% LBD incorporation, 20% LBD incorporation had fewer negative effects on mechanical and durability properties.
In Kyu Jeon; Hong Gi Kim; Sadam Hussain Jakhrani; Jae-Suk Ryou. Evaluation of the microstructure, mechanical, and durability properties of alkali-activated slag-based mortar with light-burnt dolomite powder. Journal of Materials Research and Technology 2021, 13, 2220 -2228.
AMA StyleIn Kyu Jeon, Hong Gi Kim, Sadam Hussain Jakhrani, Jae-Suk Ryou. Evaluation of the microstructure, mechanical, and durability properties of alkali-activated slag-based mortar with light-burnt dolomite powder. Journal of Materials Research and Technology. 2021; 13 ():2220-2228.
Chicago/Turabian StyleIn Kyu Jeon; Hong Gi Kim; Sadam Hussain Jakhrani; Jae-Suk Ryou. 2021. "Evaluation of the microstructure, mechanical, and durability properties of alkali-activated slag-based mortar with light-burnt dolomite powder." Journal of Materials Research and Technology 13, no. : 2220-2228.
This study conducted fundamental tests on mortars using the boron compounds recycled industrial wastes to replace uneconomic boron products. The boron compounds were three types according to the pH and the physical and neutron shielding performance of mortar mixed with boron compounds was examined. The adopted boron compounds classified as acid, slightly alkaline, and strongly alkaline with respect to the pH are acidic boric acid, alkali borax, and high alkali borax, respectively. The physical properties were evaluated by measuring the compressive strength and setting time as well as the thermal neutron shielding performance. The measured compressive strength revealed that the strengths of the specimens mixed with boron compounds were generally lower than that of the basic specimen made of control specimen. In addition, the initial and final setting times were longer than those of the control specimen. The thermal neutron shielding performances of the specimens mixed with boron compounds were higher than that of the control specimen. Consequently, the differences of the type and chemical composition of boron compounds influenced the physical properties and thermal neutron shielding performance of mortar, including its compressive strength, setting time, and neutron shielding performance. Therefore, it is important to determine the optimal amount of boron compounds in the fabrication of mortar.
Binna Lee; Byeong-Hun Woo; Jae-Suk Ryou. Basic Mechanical and Neutron Shielding Performance of Mortar Mixed with Boron Compounds with Various Alkalinity. Sustainability 2021, 13, 6252 .
AMA StyleBinna Lee, Byeong-Hun Woo, Jae-Suk Ryou. Basic Mechanical and Neutron Shielding Performance of Mortar Mixed with Boron Compounds with Various Alkalinity. Sustainability. 2021; 13 (11):6252.
Chicago/Turabian StyleBinna Lee; Byeong-Hun Woo; Jae-Suk Ryou. 2021. "Basic Mechanical and Neutron Shielding Performance of Mortar Mixed with Boron Compounds with Various Alkalinity." Sustainability 13, no. 11: 6252.
This study focused on the assessment of the ice-melting performance of cement composites using silicon carbide as fine aggregate. To assess the ice-melting performance, two mechanical and three thermal properties were measured and the results were discussed. After measuring the mechanical and thermal properties, the ice-melting test was conducted to confirm the ice-melting performance and the mechanical variation was confirmed through a splitting tensile test. The specimen that used 30% of silicon carbide as fine aggregate showed the highest compressive strength of 68.24 MPa at the 28 days of curing age and the specimens that used 100% of silicon carbide as fine aggregate were the lowest compressive strength of 38.93 MPa at the 28 days of curing age. However, the compressive strength that the case of used 100% of silicon carbide was in the acceptable range. The flexural strength increased with silicon carbide contents of up to 70%. The thermal properties including the thermal conductivity, diffusivity, and specific heat capacity showed nearly the same behaviors. These properties increased with the increase of silicon carbide content. The reason for this phenomenon was related to the volumetric occupancy of silicon carbide in the cement composite. The ice-melting test showed the decreasing of melting time with the increase of the silicon carbide content. Comprehensively, it was demonstrated that the ice-melting performance enhanced for the same reason as the thermal properties and, silicon carbide could be used as fine aggregate for improving the thermal properties.
Byeong Hun Woo; In Kyu Jeon; Dong Ho Yoo; Hong Gi Kim; Jae-Suk Ryou. Ice-melting performance assessment of cement composites using silicon carbide as fine aggregate. Applied Thermal Engineering 2021, 194, 117113 .
AMA StyleByeong Hun Woo, In Kyu Jeon, Dong Ho Yoo, Hong Gi Kim, Jae-Suk Ryou. Ice-melting performance assessment of cement composites using silicon carbide as fine aggregate. Applied Thermal Engineering. 2021; 194 ():117113.
Chicago/Turabian StyleByeong Hun Woo; In Kyu Jeon; Dong Ho Yoo; Hong Gi Kim; Jae-Suk Ryou. 2021. "Ice-melting performance assessment of cement composites using silicon carbide as fine aggregate." Applied Thermal Engineering 194, no. : 117113.
Post-tensioned anchorage zones need enough strength to resist large forces from jacking forces from prestress and need spiral reinforcement to give confinement effect. High-strength concrete (HSC) has high-strength and brings the advantage of reducing material using and simplifying reinforcing. We tested strain stabilization, load–displacement, and strain of lateral reinforcements. Specimens that used one and two lateral reinforcements without spiral reinforcement did not satisfy the strain stabilization. Load capacity also did not satisfy the condition of 1.1 times the nominal tensile strength of PS strands presented in ETAG 013. On the other hand, specimens that used three and four lateral reinforcements without spiral reinforcement satisfied the strain stabilization but did not satisfy 1.1 times the nominal tensile strength of PS strands. However, the secondary confinement effect could be confirmed from strain stabilization. In addition, the affection of HSC characteristics could be confirmed from a reinforcing level comparing other studies. The main confinement effect could be confirmed from the reinforcement strain results; there was a considerable difference between with and without spiral reinforcement at least 393 MPa. Comprehensively, main and secondary confinement effects are essential in post-tensioned anchorage zones. In addition, the performance of the anchorage zone could be increased by using HSC that the combination of high-strength and confinement effect.
Jun Lee; Byeong Woo; Jae-Suk Ryou; Jee-Sang Kim. Performance Assessment of the Post-Tensioned Anchorage Zone Using High-Strength Concrete Considering Confinement Effect. Materials 2021, 14, 1748 .
AMA StyleJun Lee, Byeong Woo, Jae-Suk Ryou, Jee-Sang Kim. Performance Assessment of the Post-Tensioned Anchorage Zone Using High-Strength Concrete Considering Confinement Effect. Materials. 2021; 14 (7):1748.
Chicago/Turabian StyleJun Lee; Byeong Woo; Jae-Suk Ryou; Jee-Sang Kim. 2021. "Performance Assessment of the Post-Tensioned Anchorage Zone Using High-Strength Concrete Considering Confinement Effect." Materials 14, no. 7: 1748.
When concrete structures are exposed to fire and high temperatures for an extended period of time, they become significantly less durable due to the decomposition of major hydration products and the evaporation of capillary water. A change in internal properties does not guarantee the stability of concrete structures and may reduce their life cycle. To preserve the durability and stability of concrete structures upon exposure to fire and high temperatures, fire-resistant mortar for exterior walls was developed in this work using zeolite, a phase change material (PCM), and magnesium hydroxide (MH). Zeolite was first coated with paraffin wax. Primary coated aggregates were then coated with MH, which was mixed with dissolved polyvinyl acetate to enhance adhesion on the surface of pre-coated aggregates. The physical and chemical properties of mortar mixed with different percentages of coated aggregates as a replacement for normal aggregates were evaluated by compressive strength tests, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Fire-resistant properties were investigated by residual compressive strength measurement tests, mass loss calculations, and mock-up tests to compare the internal temperature of mortar covered with normal and coated aggregate when heated in an electric furnace at 1000 °C. The residual compressive strength results showed a decrease in strength with a larger percentage of coated aggregates in the mortar. However, according to the mock-up test, control mortar covered with plain mortar took 5430 s (90.5 min) to reach a maximum temperature of 842 °C, while the mortar covered with 100% coated aggregate took 7170 s (119.5 min) to reach a maximum temperature of 735 °C. The obtained results indicate that the coated aggregate is a proper replacement for conventional aggregate in the development of fire-resistant mortar.
Dong Ho Yoo; In Kyu Jeon; Hong Gi Kim; Jun Suk Lee; Jae-Suk Ryou. Experimental evaluation of fire resistance performance of cement mortar with PCM/Mg(OH)2-based composite fine aggregate. Construction and Building Materials 2021, 287, 123018 .
AMA StyleDong Ho Yoo, In Kyu Jeon, Hong Gi Kim, Jun Suk Lee, Jae-Suk Ryou. Experimental evaluation of fire resistance performance of cement mortar with PCM/Mg(OH)2-based composite fine aggregate. Construction and Building Materials. 2021; 287 ():123018.
Chicago/Turabian StyleDong Ho Yoo; In Kyu Jeon; Hong Gi Kim; Jun Suk Lee; Jae-Suk Ryou. 2021. "Experimental evaluation of fire resistance performance of cement mortar with PCM/Mg(OH)2-based composite fine aggregate." Construction and Building Materials 287, no. : 123018.
In this paper, the effect of nano-SiO2 (NS) and MgO on the hydration characteristics and anti-washout resistance of non-dispersible underwater concrete (UWC) was evaluated. A slump flow test, a viscosity test, and setting time measurement were conducted to identify the impacts of NS and MgO on the rheological properties of UWC. The pH and turbidity were measured to investigate the anti-washout performance of UWC mixes. To analyze the hydration characteristics and mechanical properties, hydration heat analysis, a compressive strength test, and thermogravimetric analyses were conducted. The experimental results showed that the fine particles of NS and MgO reduced slump flow, increased viscosity, and enhanced the anti-washout resistance of UWC. In addition, both NS and MgO shortened the initial and final setting times, and the replacement of MgO specimens slightly prolonged the setting time. NS accelerated the peak time and increased the peak temperature, and MgO delayed the hydration process and reduced the temperature due to the formation of brucite. The compressive results showed that NS improved the compressive strength of the UWC, and MgO slightly decreased the strength. The addition of NS also resulted in the formation of extra C–S–H, and the replacement of MgO caused the generation of a hydrotalcite phase.
In Jeon; Byeong Woo; Dong Yoo; Jae Ryou; Hong Kim. Evaluation of the Hydration Characteristics and Anti-Washout Resistance of Non-Dispersible Underwater Concrete with Nano-SiO2 and MgO. Materials 2021, 14, 1328 .
AMA StyleIn Jeon, Byeong Woo, Dong Yoo, Jae Ryou, Hong Kim. Evaluation of the Hydration Characteristics and Anti-Washout Resistance of Non-Dispersible Underwater Concrete with Nano-SiO2 and MgO. Materials. 2021; 14 (6):1328.
Chicago/Turabian StyleIn Jeon; Byeong Woo; Dong Yoo; Jae Ryou; Hong Kim. 2021. "Evaluation of the Hydration Characteristics and Anti-Washout Resistance of Non-Dispersible Underwater Concrete with Nano-SiO2 and MgO." Materials 14, no. 6: 1328.
Water supply systems are essential elements for human life and industry, and water leaks and water supply cut-off may cause major problems. Local water leaks and pipe failures in the water supply system are inevitable problems due to the aging of pipes. Therefore, leakage detection and prevention are required to monitor the integrity of the water supply system. This paper is a fundamental study on the applicability of the smart bolt, which was developed as a monitoring system to detect water leakage in water supply monitoring. Detection experiments were conducted using a smart bolt with a built-in strain sensor and an accelerometer. Through finite element analysis using ANSYS 2019 R2 and tensile strength testing, the strength of the smart bolt was confirmed to have the acceptable tensile strength. The smart bolt used in this study was verified to meet the allowable criteria of torque and tensile stress for a municipal water supply system. The frequency responses of the simulated leakage pipe system, according to the leakage of the valve and the main pipe, were analyzed, and a leak signal at the valve leak point was detected in the 60-Hz band. The main pipe leaking point was observed to produce a leak signal with a much higher-order mode than that of the valve leak point. Therefore, the smart bolt can be applied to detect warning leak signs from water supply valves and to monitor for loosening of the bolts.
Youngseok Kim; Haewook Jung; Jaesuk Ryou; Jaehyuk Choi. A Basic Experimental Study on Analysis of Leak Signal and Monitoring Method for Water Supply Pipe. Applied Sciences 2021, 11, 2097 .
AMA StyleYoungseok Kim, Haewook Jung, Jaesuk Ryou, Jaehyuk Choi. A Basic Experimental Study on Analysis of Leak Signal and Monitoring Method for Water Supply Pipe. Applied Sciences. 2021; 11 (5):2097.
Chicago/Turabian StyleYoungseok Kim; Haewook Jung; Jaesuk Ryou; Jaehyuk Choi. 2021. "A Basic Experimental Study on Analysis of Leak Signal and Monitoring Method for Water Supply Pipe." Applied Sciences 11, no. 5: 2097.
In order to detect damage to underwater infrastructure for inspection, an expensive survey by a diver is generally conducted, but it carries the risk of accidents. Accordingly, the development of an effective unmanned underwater survey system is an important priority. The unmanned underwater survey system used in this study is equipped with sonar towed by an- Unmanned Surface Vehicle (USV) to conduct the survey, but the USV is more affected by the waves and swells than a common boat. As a result, distorted sonar data causes errors in the information regarding the damage of underwater infrastructure. This study proposes the method of sonar image stabilization to minimize the errors of the distortion of sonar data by using a motion sensor. The change in the amount of the roll was calculated from the motion sensor, and the sonar data was corrected in the sonar ping unit. The sonar image stabilization algorithm was verified through field tests, and the error rate before and after correction was reduced by 15%. It is expected that, in the future, the proposed approach will be used as a standard data-gathering system for securing the reliability of sonar data when performing an unmanned underwater survey.
Youngseok Kim; Jaesuk Ryou. A Study of Sonar Image Stabilization of Unmanned Surface Vehicle Based on Motion Sensor for Inspection of Underwater Infrastructure. Remote Sensing 2020, 12, 3481 .
AMA StyleYoungseok Kim, Jaesuk Ryou. A Study of Sonar Image Stabilization of Unmanned Surface Vehicle Based on Motion Sensor for Inspection of Underwater Infrastructure. Remote Sensing. 2020; 12 (21):3481.
Chicago/Turabian StyleYoungseok Kim; Jaesuk Ryou. 2020. "A Study of Sonar Image Stabilization of Unmanned Surface Vehicle Based on Motion Sensor for Inspection of Underwater Infrastructure." Remote Sensing 12, no. 21: 3481.
The anti-corrosion performance of coating systems (cathode protection, organic coating, and duplex coating) applied to prevent the corrosion of offshore wind power plants was assessed. As an assessment method, the adhesion strength of each coating system was evaluated after exposing the coatings to the marine environment and an indoor salt spray test. It was confirmed that the adhesion strength varied depending on the exposure period, and the deterioration of adhesion strength was related to the fracture type of each coating layer. In addition, the fracture type of each coating system was analyzed and the adhesion strength was corrected according to the fracture type. The corrosion rates after exposure to the marine environment and indoor salt spray were compared and examined using the corrected values.
Sung-Hyun Eom; Seong-Soo Kim; Jeong-Bae Lee. Assessment of Anti-Corrosion Performances of Coating Systems for Corrosion Prevention of Offshore Wind Power Steel Structures. Coatings 2020, 10, 970 .
AMA StyleSung-Hyun Eom, Seong-Soo Kim, Jeong-Bae Lee. Assessment of Anti-Corrosion Performances of Coating Systems for Corrosion Prevention of Offshore Wind Power Steel Structures. Coatings. 2020; 10 (10):970.
Chicago/Turabian StyleSung-Hyun Eom; Seong-Soo Kim; Jeong-Bae Lee. 2020. "Assessment of Anti-Corrosion Performances of Coating Systems for Corrosion Prevention of Offshore Wind Power Steel Structures." Coatings 10, no. 10: 970.
Temperature is an important factor that affects corrosion potential in rebars. The temperature effect must be removed from the corrosion potential for precise measurement of corrosion rates. To separate the temperature effect from the corrosion potential, in this study rebar specimens were not embedded in concrete but, instead, were placed in an uncontrolled air environment. Gaussian process regression (GPR) was applied to the temperature and the non-corrosion potential data in order to remove the temperature effect from the corrosion potential. The results indicated that the corrosion potential was affected by the temperature. Furthermore, the GPR models of all the experimental cases showed high coefficients of determination (R2 > 0.90) and low root mean square errors (RMSE < 0.08), meaning that these models had high reliability. The fitted GPR models were used to successfully remove the temperature effect from the corrosion potential. This demonstrates that the GPR method can be appropriately used to assess the temperature effect on rebar corrosion.
Byeong Hun Woo; In Kyu Jeon; Seong Soo Kim; Jeong Bae Lee; Jae-Suk Ryou. An Experimental and Statistical Study on Rebar Corrosion Considering the Temperature Effect Using Gaussian Process Regression. Applied Sciences 2020, 10, 5937 .
AMA StyleByeong Hun Woo, In Kyu Jeon, Seong Soo Kim, Jeong Bae Lee, Jae-Suk Ryou. An Experimental and Statistical Study on Rebar Corrosion Considering the Temperature Effect Using Gaussian Process Regression. Applied Sciences. 2020; 10 (17):5937.
Chicago/Turabian StyleByeong Hun Woo; In Kyu Jeon; Seong Soo Kim; Jeong Bae Lee; Jae-Suk Ryou. 2020. "An Experimental and Statistical Study on Rebar Corrosion Considering the Temperature Effect Using Gaussian Process Regression." Applied Sciences 10, no. 17: 5937.
This study used PCM/SiC-based composite aggregates made using slag aggregate, paraffin wax, and silicon carbide. Concrete samples were prepared by replacing natural coarse aggregates with PCM/SiC-based composite aggregates at various replacement ratios. Compressive strength tests, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy-energy dispersive microscopy analysis were carried out to investigate the mechanical, physical, and microstructural properties of concrete samples. The results reveal that physical properties of the concrete samples made with PCM/SiC-based composite aggregate were less desirable than those made without PCM/SiC-based composite aggregates. However, the targeted designed strength was not compromised with the addition of PCM/SiC-based composite aggregate. The results of microstructural analyses confirmed the presence of various hydration products, paraffin wax, and SiC particles in the cement composites.
Hong Gi Kim; Abdul Qudoos; In Kyu Jeon; Jae Suk Ryou. Assessment of PCM/SiC-based composite aggregate in concrete: Mechanical, physical and microstructural properties. Construction and Building Materials 2020, 262, 120088 .
AMA StyleHong Gi Kim, Abdul Qudoos, In Kyu Jeon, Jae Suk Ryou. Assessment of PCM/SiC-based composite aggregate in concrete: Mechanical, physical and microstructural properties. Construction and Building Materials. 2020; 262 ():120088.
Chicago/Turabian StyleHong Gi Kim; Abdul Qudoos; In Kyu Jeon; Jae Suk Ryou. 2020. "Assessment of PCM/SiC-based composite aggregate in concrete: Mechanical, physical and microstructural properties." Construction and Building Materials 262, no. : 120088.
This work investigates the thermal energy storage performance of concrete using a phase change material (PCM)/SiC-based composite aggregate made with paraffin wax, silicon carbide, and slag aggregate. The thermal energy storage properties were evaluated using a differential scanning calorimetry (DSC) curve, thermal conductivity, hydration heat development, and internal temperature measurements. In addition, a mock-up concrete structure was constructed to evaluate thermal energy storage under natural conditions. The DSC curve showed that the PCM/SiC-based composite aggregate changed its phase and stored thermal energy at 33–34 °C. The internal temperature test indicated that the temperature of the sample with PCM/SiC-based composite aggregate was approximately 2–10 °C higher because of the thermal heat storage capacity of the PCM/SiC-based composite aggregate. A wall surface temperature of 42 °C and 45 °C, respectively at the internal and external side of the energy storage structure wall was measured. While an indoor temperature of 35 °C was observed for energy storage structure. However, the internal surface temperature of the plain structure wall and the indoor room temperature were 41 °C and 38 °C, respectively. The concrete structure with PCM/SiC-based composite aggregate decreased the room temperature and stored thermal energy of approximately 3 °C.
Hong Gi Kim; Abdul Qudoos; In Kyu Jeon; Byeong Hun Woo; Jae Suk Ryou. Assessment of PCM/SiC-based composite aggregate in concrete: Energy storage performance. Construction and Building Materials 2020, 258, 119637 .
AMA StyleHong Gi Kim, Abdul Qudoos, In Kyu Jeon, Byeong Hun Woo, Jae Suk Ryou. Assessment of PCM/SiC-based composite aggregate in concrete: Energy storage performance. Construction and Building Materials. 2020; 258 ():119637.
Chicago/Turabian StyleHong Gi Kim; Abdul Qudoos; In Kyu Jeon; Byeong Hun Woo; Jae Suk Ryou. 2020. "Assessment of PCM/SiC-based composite aggregate in concrete: Energy storage performance." Construction and Building Materials 258, no. : 119637.
Increasing use of cement in the construction industry is causing an alarming increase in carbon dioxide (CO2) emissions, which is a serious environmental threat, it can be reduced by the addition of supplementary cementitious materials (SCMs). The commonly used SCMs like ground granulated blast furnace slag (GGBS), metakaolin (MK) and fly ash (FA) have been successfully used to replace the cement partially or completely. Polysilicon sludge obtained from the photovoltaic industry is also a type of waste material that can be used as SCM because it has high content of reactive SiO2. This study investigates the effects of replacing cement with polysilicon sludge in concrete. Different concrete specimens were made by replacing varying proportions of cement with polysilicon sludge and their properties, such as, fresh properties, compressive strength, heat release, chloride penetration, freeze/thaw resistance and microstructural investigations were determined. The results demonstrate that the polysilicon sludge can be used effectively to replace cement, and environmental threats associated with its disposal can be reduced.
Abdul Qudoos; In Kyu Jeon; Seong Soo Kim; Jeong Bae Lee; Hong Gi Kim. Utilization of Waste Polysilicon Sludge in Concrete. Materials 2020, 13, 251 .
AMA StyleAbdul Qudoos, In Kyu Jeon, Seong Soo Kim, Jeong Bae Lee, Hong Gi Kim. Utilization of Waste Polysilicon Sludge in Concrete. Materials. 2020; 13 (1):251.
Chicago/Turabian StyleAbdul Qudoos; In Kyu Jeon; Seong Soo Kim; Jeong Bae Lee; Hong Gi Kim. 2020. "Utilization of Waste Polysilicon Sludge in Concrete." Materials 13, no. 1: 251.
Globally, concrete is the most widely used construction material. The composition of concrete plays an important role in controlling its overall performance. Concrete is composed of approximately 70%-80% aggregates, by volume. Therefore, it is mandatory to investigate the effect of aggregates on the performance of concrete. For this purpose, this study investigated the effect of three different coarse aggregates on the mechanical properties, durability, and microstructure of concrete. Concrete specimens were made using aggregates obtained from three regions with different mineralogies. The specimens were also made by replacing cement with silica fume. The specimens were analyzed in terms of compressive, flexural, and splitting tensile strengths, chloride penetration, carbonation, mercury intrusion porosimetry, and scanning electron microscopy. The results demonstrate that the specimens made with rougher coarse aggregates and silica fume had enhanced performance in comparison to those made with smoother aggregates.
Seong Soo Kim; Abdul Qudoos; Sadam Hussain Jakhrani; Jeong Bae Lee; Hong Gi Kim. Influence of Coarse Aggregates and Silica Fume on the Mechanical Properties, Durability, and Microstructure of Concrete. Materials 2019, 12, 3324 .
AMA StyleSeong Soo Kim, Abdul Qudoos, Sadam Hussain Jakhrani, Jeong Bae Lee, Hong Gi Kim. Influence of Coarse Aggregates and Silica Fume on the Mechanical Properties, Durability, and Microstructure of Concrete. Materials. 2019; 12 (20):3324.
Chicago/Turabian StyleSeong Soo Kim; Abdul Qudoos; Sadam Hussain Jakhrani; Jeong Bae Lee; Hong Gi Kim. 2019. "Influence of Coarse Aggregates and Silica Fume on the Mechanical Properties, Durability, and Microstructure of Concrete." Materials 12, no. 20: 3324.
Exposure of concrete to aggressive environments such as sewage drains can cause significant damage to the concrete and decrease its durability. Fillers can be used to improve the resistance of cement concrete against aggressive environment. In this study, silicon carbide was used as a partial replacement for fine aggregate in fractions up to 10% by weight. Specimens were fabricated and exposed to water and sulfuric acid solution. The specimens were examined for various parameters i.e. mass change, compressive strength change, ultrasonic pulse velocity, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction analysis, and scanning electron microscopy. The results indicate that silicon carbide particles play an important role by filling the pores inside the cement composites and densifying the microstructure due to the filler effect. The cement mortars containing silicon carbide showed improved resistance to sulfuric acid attack and this behavior was enhanced with the increase in silicon carbide content.
In Kyu Jeon; Abdul Qudoos; Sadam Hussain Jakhrani; Hong Gi Kim; Jae-Suk Ryou. Investigation of sulfuric acid attack upon cement mortars containing silicon carbide powder. Powder Technology 2019, 359, 181 -189.
AMA StyleIn Kyu Jeon, Abdul Qudoos, Sadam Hussain Jakhrani, Hong Gi Kim, Jae-Suk Ryou. Investigation of sulfuric acid attack upon cement mortars containing silicon carbide powder. Powder Technology. 2019; 359 ():181-189.
Chicago/Turabian StyleIn Kyu Jeon; Abdul Qudoos; Sadam Hussain Jakhrani; Hong Gi Kim; Jae-Suk Ryou. 2019. "Investigation of sulfuric acid attack upon cement mortars containing silicon carbide powder." Powder Technology 359, no. : 181-189.
This study investigates the potential of light-burnt dolomite (LBD) as a supplementary cementitious material with ground granulated blast furnace slag (GGBFS) and Ordinary Portland cement (OPC). In this work, LBD was substituted for up to 20% of GGBFS in sodium sulfate-activated slag systems. The effects of LBD incorporation on the flow, setting time, compressive and flexural strength development, and drying shrinkage were explored with, X-ray diffraction and thermogravimetric analyses. LBD incorporation resulted in greater strength development of an alkali-activated slag system. The optimum LBD content for strength development was 10%, regardless of ordinary Portland cement content. In addition, LBD decreased the drying shrinkage, accelerated the hydration process, and induced hydrotalcite formation, which can be attributed to the reactive MgO inside LBD.
In Kyu Jeon; Jae Suk Ryou; Sadam Hussain Jakhrani; Hong Gi Kim. Effects of Light-Burnt Dolomite Incorporation on the Setting, Strength, and Drying Shrinkage of One-Part Alkali-Activated Slag Cement. Materials 2019, 12, 2874 .
AMA StyleIn Kyu Jeon, Jae Suk Ryou, Sadam Hussain Jakhrani, Hong Gi Kim. Effects of Light-Burnt Dolomite Incorporation on the Setting, Strength, and Drying Shrinkage of One-Part Alkali-Activated Slag Cement. Materials. 2019; 12 (18):2874.
Chicago/Turabian StyleIn Kyu Jeon; Jae Suk Ryou; Sadam Hussain Jakhrani; Hong Gi Kim. 2019. "Effects of Light-Burnt Dolomite Incorporation on the Setting, Strength, and Drying Shrinkage of One-Part Alkali-Activated Slag Cement." Materials 12, no. 18: 2874.
The purpose of this study was to prevent early age autogenous shrinkage in high-strength mortars with saturated tea waste particles. In general, high strength and high performance concretes are made with low water/binder ratios; hence, they are susceptible to shrink at early ages. This shrinkage occurs due to self-desiccation that leads to autogenous shrinkage. To overcome self-desiccation problems in high-strength cement composites, it is necessary to keep the composites moist for a long time. Pre-saturated porous lightweight aggregates and super absorbent polymers are the most commonly used materials in high-strength cement composites to keep them moist for a long time; however, in this study, porous tea waste particles were used to keep the cement mortars moist. Pre-saturated tea waste particles were used in two different size proportions, making up as much as 3% of the volume of the binder. Moreover, commonly used lightweight aggregate (perlite) was also used to compare the outcomes of specimens made with tea waste particles. Different parameters were observed, such as, flow of fresh mortars, autogenous shrinkage, mechanical strengths and microstructure of specimens. The addition of tea waste and perlite particles in mortars made with Ordinary Portland cement (OPC) as the only binder, showed a reduction in flow, autogenous shrinkage and mechanical strengths, as compared to mixes made with partial addition of silica fume. Although, the use of silica fume improved the mechanical strength of specimens. Moreover, the use of saturated tea waste and perlite particles also improved the microstructure of specimens at an age of 28 days. The results revealed that the saturated tea waste particles have the ability to prevent autogenous shrinkage but they reduce strength of high-strength mortars at early ages.
Sadam Hussain Jakhrani; Jae Suk Ryou; Atta- Ur- Rehman; In Kyu Jeon; Byeong Hun Woo; Hong Gi Kim. Prevention of Autogenous Shrinkage in High-Strength Mortars with Saturated Tea Waste Particles. Materials 2019, 12, 2654 .
AMA StyleSadam Hussain Jakhrani, Jae Suk Ryou, Atta- Ur- Rehman, In Kyu Jeon, Byeong Hun Woo, Hong Gi Kim. Prevention of Autogenous Shrinkage in High-Strength Mortars with Saturated Tea Waste Particles. Materials. 2019; 12 (17):2654.
Chicago/Turabian StyleSadam Hussain Jakhrani; Jae Suk Ryou; Atta- Ur- Rehman; In Kyu Jeon; Byeong Hun Woo; Hong Gi Kim. 2019. "Prevention of Autogenous Shrinkage in High-Strength Mortars with Saturated Tea Waste Particles." Materials 12, no. 17: 2654.
The main purpose of this work is to study the effect of saturated black tea waste and perlite on controlling the rapid heat of hydration in high-strength cement mortars at early ages. Tea waste and perlite were investigated as internal curing agents in different mixes. Mortar specimens with two different sizes of tea waste and perlite particles with 1 and 3% by volume of cement were added in different mixes to find their effect on early age hydration. The rising interior temperature, setting times, and strength parameters were evaluated. Results showed that the mix specimens that contained 3% tea waste and perlite particles significantly delayed the hydration process by minimizing internal temperature and extended setting times of different specimens. However, their usage had a slightly adverse impact on compressive and flexural strengths. It was observed that the specimens made with coarser particles of tea waste and perlite were more helpful to control early age rapid hydration than the specimens made with finer particles, whereas the specimens made with finer particles had slightly higher strengths than the specimens made with coarser particles. Hence, the coarser particles are recommended to be used in high-strength mortars to mitigate the early age rapid heat of hydration.
Sadam Hussain Jakhrani; Hong Gi Kim; In Kyu Jeon; Jae Suk Ryou. Effect of Saturated Tea Waste and Perlite Particles on Early Age Hydration of High-Strength Cement Mortars. Materials 2019, 12, 2269 .
AMA StyleSadam Hussain Jakhrani, Hong Gi Kim, In Kyu Jeon, Jae Suk Ryou. Effect of Saturated Tea Waste and Perlite Particles on Early Age Hydration of High-Strength Cement Mortars. Materials. 2019; 12 (14):2269.
Chicago/Turabian StyleSadam Hussain Jakhrani; Hong Gi Kim; In Kyu Jeon; Jae Suk Ryou. 2019. "Effect of Saturated Tea Waste and Perlite Particles on Early Age Hydration of High-Strength Cement Mortars." Materials 12, no. 14: 2269.