양현민 교수

Steel has versatile application in chemical, structure and construction industries owing to its mechanical properties. However, it is susceptible to corrosion in acid environments. Thus, it requires to protect the steel from corrosion. Different types of corrosion resistance steel, coatings and inhibitors are developed to mitigate the corrosion, but, inhibitor is the best remedies to control the corrosion of steel in acid condition. Moreover, organic and green inhibitors used in acid condition f

The cement industries as binder materials, produces 1.6 billion metric tons’ carbon dioxide (CO2) in 2022 and cause depletion in ozone layer. The cement is being used in modern construction and cause the environmental impact. Therefore, there is a quest for a sustainable alternative binder to reduce the CO2 emission from the conventional cement production and their effective disposal methods in construction and demolished (C&D) waste is paramount. This article delves into the production of recyc

Ground granulated blast furnace slag (GGBFS) conventionally has been incorporated with ordinary Portland cement (OPC) owing to reduce the environmental load and enhance the engineering performance. Concrete with GGBFS shows different strength development of normal concrete, but sensitive, to exterior condition. Thus, a precise strength evaluation technique based on a quantitative model like full maturity model is required. Many studies have been performed on strength development of the concrete

Zinc (Zn) coating is being used to protect steel structures from corrosion. There are different processes to deposit the coating onto a steel substrate. Therefore, in the present study, a 100 µm thick Zn coating was deposited by arc and plasma arc thermal spray coating processes, and the corrosion resistance performance was evaluated in artificial seawater. Scanning electron microscopy (SEM) results showed that the arc thermal spray coating exhibited splats and inflight particles, whereas plasma

L-arginine is one of the amino acids found in plant seeds. In the present study, various amounts (i.e., 3%, 5%, 10%) of L-arginine were added to cement mortar to investigate the compressive strength, workability, leaching behavior, and pH change in distilled and natural seawater, as well as dissolved nitrogen and growth of chlorophyll-a (Chl-a) by immersion in natural seawater. The compressive strength of the cement mortar is decreased with increase in L-arginine content owing to the high flow/s

γ-Dicalcium silicate (γ-C2S) is known for its strong carbonation reactivity by which it can capture atmospheric carbon dioxide (CO2), thus, it can be used in construction industries. This paper aims to study the effects of γ-C2S on the properties of ground granulated blast-furnace slag (GGBFS) containing cement mortar and paste in natural and accelerated carbonation curing. The compressive strength of 5% γ-C2S (G5) added to GGBFS cement mortar is higher compared with the control one in natural c

High fluidity concrete exhibits an excellent self-compacting property. However, the application of typical high-fluidity concrete is limited in the normal strength range (18~35 MPa) due to the large amount of binder. Therefore, it is important to solve these problems by adding a viscosity modifying agent (VMA) with a superplasticizer (PCE), which helps to improve the fluidity of the concrete. In addition, the rheology and stability of the concrete with VMA can be improved by preventing bleeding

Blended cement is commonly used for producing sustainable concretes. This paper presents an experimental study and an optimization design of a low-CO₂ quaternary binder containing calcined clay, slag, and limestone using the response surface method. First, a Box-Behnken design with three influencing factors and three levels was used for the combination design of the quaternary composite cement. The lower limit of the mineral admixtures was 0%. The upper limits of slag, calcined clay,

In the present study, 0.115 M L-arginine (LA) has been used as an eco-friendly inhibitor in simulated concrete pore solutions (SP-0) in order to form passive films on a steel rebar-solution interface until 144 h. Hence, 0.51 (SP-1) and 0.85 M NaCl (SP-2) were added in LA containing SP-0 solution to breakdown the passive film and to initiate corrosion reactions. The electrochemical results show that the charge transfer resistance (<i>R_ct</i>) of steel rebar exposed to SP-1 and SP-2 sol

Porous silicon nitride structures were fabricated for a humidity sensor. The porous silicon structures were fabricated by the metal-assisted chemical etching process, and the conformal silicon nitride thin film was deposited by the atomic layer deposition process. The optimized porous sensor with the 10 nm-thick silicon nitride thin film had a hydrophilic surface and compared to other sensors, had an excellent humidity sensing response. Especially, it showed a superior humidity sensing response

In the present studies, ginger powder has been used as an eco-friendly admixture for the cement mortar. Different amounts i.e. 0 wt% (M1), 0.10 wt% (M2), 0.25 wt% (M3) and 0.50 wt% (M4) ginger powder was mixed in the cement mortar (M1) and assessed the durability. The ginger powder with 0.50 wt% (M4) improves the compressive strength by 17 % owing to the water reducing capability, which enhance the hydration reaction and fill the pore matrix of the cement mortar. The active ingredient of ginger

Industrial sludge byproducts contain CaO, SiO2, Al2O3, etc. When industrial sludge is used in ready-mixed concrete, the performance of the concrete can be enhanced due to the hydration reaction. In the present study, activated sludge was used to prepare ready-mixed concrete, and its durability performance was evaluated. Once the activated sludge was used, the durability of the concrete improved. Therefore, it is suggested that activated sludge can be used in concrete mix as an admixture.