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As jointed plain concrete pavements (JPCP) age in South Korea, the cost of pavement maintenance is increasing annually. To extend the life of jointed concrete pavements through preventive maintenance, this study used 2017 pavement management system data to analyze the effects of traffic volume, alkali–silica reaction (ASR) grade, age, smoothness, and damaged area on the remodeling index (RMI—a measure of expressway pavement condition). In addition, this study evaluates the final RMI as well as the corresponding pavement condition and change in RMI value after conducting preventive maintenance in lieu of resurfacing or overlaying. The results demonstrated that the effect of ASR grade increased as the RMI forecast year increased and that change in surface distress (△SD) increased with age (most intensively when the pavement was 15–20 years of age). Moreover, change in international roughness index (△IRI) increased with age and traffic volume (similarly within 15–20 years of pavement age). Hence, preventive maintenance is a must for sections with high traffic volume and age even if the RMI is low. Finally, performing repairs through preventive maintenance decreases the number of expressway sections requiring resurfacing and overlaying, thus extending the life of the concrete pavement.
Haekook Jung; Yongjae Kim; Seungwon Kim; Cheolwoo Park; Jeong-Hee Nam. Life Extension of Aged Jointed Plain Concrete Pavement through Remodeling Index–Based Analysis. Materials 2020, 13, 2982 .
AMA StyleHaekook Jung, Yongjae Kim, Seungwon Kim, Cheolwoo Park, Jeong-Hee Nam. Life Extension of Aged Jointed Plain Concrete Pavement through Remodeling Index–Based Analysis. Materials. 2020; 13 (13):2982.
Chicago/Turabian StyleHaekook Jung; Yongjae Kim; Seungwon Kim; Cheolwoo Park; Jeong-Hee Nam. 2020. "Life Extension of Aged Jointed Plain Concrete Pavement through Remodeling Index–Based Analysis." Materials 13, no. 13: 2982.
Many researchers have studied explosion prevention and fire resistance of high-strength concrete mixed with organic fiber and steel fibers. The fire resistance of high-performance fiber reinforced cement composites is desirable in terms of physical and mechanical properties. However, the use of a polymer as an alternative to organic fiber has not been clearly studied. In this study, a slurry infiltration method was used to obtain slurry-infiltrated fiber-reinforced cementitious composites (SIFRCCs) specimens. Powder polymer was used instead of organic fibers during mixing of the slurry. The compressive and flexural strengths of the specimens after 1 hr of high temperature exposure according to the KS F 2257 (ISO 834) standard fire-temperature curve were measured. The addition of the polymer before and after high temperature (about 945 °C) exposure affected the strength of the SIFRCCs. The compressive and flexural strengths were decreased after exposure to high temperature in comparison with SIFRCCs without polymer because polymer create capillary pores due to melting and burning when exposure to high temperature. This minimizes the vapor pressure inside the concrete model and reduces the failure of the concrete model. The experimental results showed that the flexural strength at a high temperature for 1.0 % polymer content was the highest at 53.8 MPa. The flexural strength was reduced by 40~50% when compared to the flexural strength before high temperature exposure and comparing to SIFRCCs without polymer, the compressive strength in 1.5% polymer is lower, owing to voids that are created in the SIFRCCs after exposure to a high temperature.
Seungwon Kim; Topendra Oli; Cheolwoo Park. Effect of Exposure to High Temperature on the Mechanical Properties of SIFRCCs. Applied Sciences 2020, 10, 2142 .
AMA StyleSeungwon Kim, Topendra Oli, Cheolwoo Park. Effect of Exposure to High Temperature on the Mechanical Properties of SIFRCCs. Applied Sciences. 2020; 10 (6):2142.
Chicago/Turabian StyleSeungwon Kim; Topendra Oli; Cheolwoo Park. 2020. "Effect of Exposure to High Temperature on the Mechanical Properties of SIFRCCs." Applied Sciences 10, no. 6: 2142.
Conventional concrete is a brittle material with a very low tensile strength as a result of compressive strength and tensile strain. In this study, the flexural behavior characteristics of slurry-infiltrated fiber-reinforced cementitious composites (SIFRCCs) based on slurry-infiltrated fiber concrete (SIFCON), such as high-performance fiber-reinforced cementitious composites (HPFRCCs), were analyzed to maximize the fiber volume fraction and increase resistance to loads with very short working times (such as explosions or impacts). For extensive experimental variables, one fiber aspect ratio and three fiber volume fractions (6%, 5%, and 4%) were designed, and the flexural toughness and strength were figured out with respect to variables. A maximum flexural strength of 45 MPa was presented for a fiber volume fraction of 6%, and it was found that by increasing the fiber volume fraction the flexural strength and toughness increased. The test results with respect to fiber volume fraction revealed that after the initial crack, the load of SIFRCCs frequently increased because of the high fiber volume fraction. In addition to maximum strength, acceptable strength was found, which could have a positive effect on brittle fractures in structures where an accidental load is applied (such as an impact or explosion).
Seungwon Kim; Cheolwoo Park; Yongjae Kim. Effect of SIFRCCs with Varying Steel Fiber Volume Fractions on Flexural Behavior. Applied Sciences 2020, 10, 2072 .
AMA StyleSeungwon Kim, Cheolwoo Park, Yongjae Kim. Effect of SIFRCCs with Varying Steel Fiber Volume Fractions on Flexural Behavior. Applied Sciences. 2020; 10 (6):2072.
Chicago/Turabian StyleSeungwon Kim; Cheolwoo Park; Yongjae Kim. 2020. "Effect of SIFRCCs with Varying Steel Fiber Volume Fractions on Flexural Behavior." Applied Sciences 10, no. 6: 2072.
The recent abnormal temperature phenomena such as the rise of global mean temperature and sea level due to global climate change are clear threats that can no longer be overlooked to the human beings who have pursued indiscriminate development and rapid growth. Climate change has emerged as a serious risk that threatens the survival of the entire human race from the environmental and ecological aspects, despite international efforts for several decades. The CO2 concentration in the atmosphere has increased by approximately 39% since the industrial revolution. Even if carbon emissions are stopped right now, it is expected to take at least 50–200 years to return to the CO2 level before the industrial revolution. Therefore, we conducted an experimental study to develop a carbon-capturing concrete that has active as well as passive carbon reduction functions using blast-furnace slag, an industrial byproduct, instead of cement. For active carbon reduction, we used calcium hydroxide and sodium silicate as carbon capture activators, and conducted tests on mechanical properties and durability characteristics.
Seungwon Kim; Cheolwoo Park. Durability and Mechanical Characteristics of Blast-Furnace Slag Based Activated Carbon-Capturing Concrete with Respect to Cement Content. Applied Sciences 2020, 10, 2083 .
AMA StyleSeungwon Kim, Cheolwoo Park. Durability and Mechanical Characteristics of Blast-Furnace Slag Based Activated Carbon-Capturing Concrete with Respect to Cement Content. Applied Sciences. 2020; 10 (6):2083.
Chicago/Turabian StyleSeungwon Kim; Cheolwoo Park. 2020. "Durability and Mechanical Characteristics of Blast-Furnace Slag Based Activated Carbon-Capturing Concrete with Respect to Cement Content." Applied Sciences 10, no. 6: 2083.
The compressive stress of concrete is used as a design variable for reinforced concrete structures in design standards. However, as the performance-based design is being used with increasing varieties and strengths of concrete and reinforcement bars, mechanical properties other than the compressive stress of concrete are sometimes used as major design variables. In particular, the evaluation of the mechanical properties of concrete is crucial when using fiber-reinforced concrete. Studies of high volume fractions in established compressive behavior prediction equations are insufficient compared to studies of conventional fiber-reinforced concrete. Furthermore, existing prediction equations for the mechanical properties of high-performance fiber-reinforced cementitious composite and high-strength concrete have limitations in terms of the strength and characteristics of contained fibers (diameter, length, volume fraction) even though the stress-strain relationship is determined by these factors. Therefore, this study developed a high-performance slurry-infiltrated fiber-reinforced cementitious composite that could prevent the fiber ball phenomenon, a disadvantage of conventional fiber-reinforced concrete, and maximize the fiber volume fraction. Then, the behavior characteristics under compressive stress were analyzed for fiber volume fractions of 4%, 5%, and 6%.
Seungwon Kim; Seungyeon Han; Cheolwoo Park; Kyong-Ku Yun. Compressive Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composites (SIFRCCs) under Uniaxial Compressive Stress. Materials 2020, 13, 159 .
AMA StyleSeungwon Kim, Seungyeon Han, Cheolwoo Park, Kyong-Ku Yun. Compressive Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composites (SIFRCCs) under Uniaxial Compressive Stress. Materials. 2020; 13 (1):159.
Chicago/Turabian StyleSeungwon Kim; Seungyeon Han; Cheolwoo Park; Kyong-Ku Yun. 2020. "Compressive Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composites (SIFRCCs) under Uniaxial Compressive Stress." Materials 13, no. 1: 159.
Fire in a tunnel or an underground structure is characterized by a rise in temperature above 1000 °C in 5–10 min, which is due to the characteristics of the closed space. The Permanent International Association of Road Congresses has reported that serious damage can occur in an underground structure as a consequence of high temperatures of up to 1400 °C when a fire accident involving a tank lorry occurs in an underground space. In these circumstances, it is difficult to approach the scene and extinguish the fire, and the result is often casualties and damage to facilities. When a concrete structure is exposed to a high temperature, spalling or dehydration occurs. As a result, the cross section of the structure is lost, and the structural stability declines to a great extent. Furthermore, the mechanical and thermal properties of concrete are degraded by the temperature hysteresis that occurs at high temperatures. Consequently, interest in the fire safety of underground structures, including tunnels, has steadily increased. This study conducted a fire simulation to analyze the effects of a fire caused by dangerous-goods vehicles on the tunnel structure. In addition, a fire exposure test of reinforced-concrete members was conducted using the Richtlinien für die Ausstattung und den Betrieb von Straßentunneln (RABT) fire curve, which is used to simulate a tunnel fire.
Seungwon Kim; Jaewon Shim; Ji Young Rhee; Daegyun Jung; Cheolwoo Park. Temperature Distribution Characteristics of Concrete during Fire Occurrence in a Tunnel. Applied Sciences 2019, 9, 4740 .
AMA StyleSeungwon Kim, Jaewon Shim, Ji Young Rhee, Daegyun Jung, Cheolwoo Park. Temperature Distribution Characteristics of Concrete during Fire Occurrence in a Tunnel. Applied Sciences. 2019; 9 (22):4740.
Chicago/Turabian StyleSeungwon Kim; Jaewon Shim; Ji Young Rhee; Daegyun Jung; Cheolwoo Park. 2019. "Temperature Distribution Characteristics of Concrete during Fire Occurrence in a Tunnel." Applied Sciences 9, no. 22: 4740.
Concrete has high compressive strength, but low tensile strength, bending strength, toughness, low resistance to cracking, and brittle fracture characteristics. To overcome these problems, fiber-reinforced concrete, in which the strength of concrete is improved by inserting fibers, is being used. Recently, high-performance fiber-reinforced cementitious composites (HPFRCCs) have been extensively researched. The disadvantages of conventional concrete such as low tensile stress, strain capacity, and energy absorption capacity, have been overcome using HPFRCCs, but they have a weakness in that the fiber reinforcement has only 2% fiber volume fraction. In this study, slurry infiltrated fiber reinforced cementitious composites (SIFRCCs), which can maximize the fiber volume fraction (up to 8%), was developed, and an experimental study on the tensile behavior of SIFRCCs with varying fiber volume fractions (4%, 5%, and 6%) was carried out through direct tensile tests. The results showed that the specimen with high fiber volume fraction exhibited high direct tensile strength and improved brittleness. As per the results, the direct tensile strength is approximately 15.5 MPa, and the energy absorption capacity was excellent. Furthermore, the bridging effect of steel fibers induced strain hardening behavior and multiple cracks, which increased the direct tensile strength and energy absorption capacity.
Seungwon Kim; Dong Joo Kim; Sung-Wook Kim; Cheolwoo Park. Tensile Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composite with Respect to Fiber Volume Fraction. Materials 2019, 12, 3335 .
AMA StyleSeungwon Kim, Dong Joo Kim, Sung-Wook Kim, Cheolwoo Park. Tensile Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composite with Respect to Fiber Volume Fraction. Materials. 2019; 12 (20):3335.
Chicago/Turabian StyleSeungwon Kim; Dong Joo Kim; Sung-Wook Kim; Cheolwoo Park. 2019. "Tensile Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composite with Respect to Fiber Volume Fraction." Materials 12, no. 20: 3335.
Seungwon Kim; Cheolwoo Park. Flexural Behavior Characteristics of High Performance Slurry Infiltrated Fiber Reinforced Cementitious Composite with Respect to Exposure to High Temperature. Journal of the Korea Concrete Institute 2019, 31, 139 -146.
AMA StyleSeungwon Kim, Cheolwoo Park. Flexural Behavior Characteristics of High Performance Slurry Infiltrated Fiber Reinforced Cementitious Composite with Respect to Exposure to High Temperature. Journal of the Korea Concrete Institute. 2019; 31 (2):139-146.
Chicago/Turabian StyleSeungwon Kim; Cheolwoo Park. 2019. "Flexural Behavior Characteristics of High Performance Slurry Infiltrated Fiber Reinforced Cementitious Composite with Respect to Exposure to High Temperature." Journal of the Korea Concrete Institute 31, no. 2: 139-146.
High-performance fiber-reinforced cementitious composites (HPFRCCs) are characterized by unique tensile strain hardening and multiple microcracking behaviors. The HPFRCC, which demonstrates remarkable properties such as strength, ductility, toughness, durability, stiffness, and thermal resistance, is a class of fiber cement composite with fine aggregates. It can withstand tensile stresses by forming distributed microcracks owing to the embedded fibers in the concrete, which improve the energy absorption capacity and apparent ductility. This high energy absorbing capacity can be enhanced further by an external stiff fiber-reinforced polymer (FRP). Basalt fabric is externally bonded as a sheet on concrete materials to enhance the durability and resistance to fire and other environmental attacks. This study investigates the flexural performance of an HPFRCC that is externally reinforced with multiple layers of basalt FRP. The HPFRCC considered in the study contains steel fibers at a volume fraction of 8%.
Seungwon Kim; Cheolwoo Park. Flexural Behavior of High-Volume Steel Fiber Cementitious Composite Externally Reinforced with Basalt FRP Sheet. Journal of Engineering 2016, 2016, 1 -9.
AMA StyleSeungwon Kim, Cheolwoo Park. Flexural Behavior of High-Volume Steel Fiber Cementitious Composite Externally Reinforced with Basalt FRP Sheet. Journal of Engineering. 2016; 2016 ():1-9.
Chicago/Turabian StyleSeungwon Kim; Cheolwoo Park. 2016. "Flexural Behavior of High-Volume Steel Fiber Cementitious Composite Externally Reinforced with Basalt FRP Sheet." Journal of Engineering 2016, no. : 1-9.