• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.54-58
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• 1998

This experiment was conducted to find out the effects of fermented compost using cattle manure and Autoclaved Lightweight Concrete(ALC) waste and duck raising in rice growing paddy fields on growth and quality of rice. By application of fermented compost of cattle manure incoporated ALC waste with amount of 2,000kg/10a, rice yield was reduced 2.9%, and 4.1% in 1,000kg/10a of compost with raising ducks plots as compared with application of standard level of chemical fertilizer. The ratio of head rice was slightly high in plots of compost application and white-belly kemeled rice was reduced by application of $1,500{\sim}2000kg/10a$ compost. The ratio of Mg/K was the highest in application of 1,000kg compost with raising duck. Efficiency of weed control by raising duck with free hexbiades was sufficient and their effects showed no difference between raising duck plots and herbidde plot.

• Steel and Composite Structures
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• v.49 no.2
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• pp.245-255
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• 2023

The present paper summarizes the results of an experimental program on the influence of using waste lathe scraps in the concrete mixture on the shear behavior of RC beams with different amounts of shear reinforcement. Three different volumetric ratios (1, 2 and %3) for the scraps and three different stirrup spacings (160, 200 and 270 mm) were adopted in the tests. The shear span-to-depth ratios of the beams were 2.67 and the stirrup spacing exceeded the maximum spacing limit in the building codes to unfold the contribution of lathe scraps to the shear resistances of shear-deficient beams, subject to shear-dominated failure (shear-tension). The experiments depicted that the lathe scraps have a pronounced contribution to the shear strength and load-deflection behavior of RC beams with widely-spaced stirrups. Namely, with the addition of 1%, 2% and 3% waste lathe scraps, the load-bearing capacity escalated by 9.1%, 21.8% and 32.8%, respectively, compared to the reference beam. On the other hand, the contribution of the lathe scraps to the load capacity decreases with decreasing stirrup spacing, since the closely-spaced stirrups bear the shear stresses and render the contribution of the scraps to shear resistance insignificant. The load capacity, deformation ductility index (DDI) and modulus of toughness (MOT) values of the beams were shown to increase with the volumetric fraction of scraps if the stirrups are spaced at about two times the beam depth. For the specimens with a stirrup spacing of about the beam depth, the scraps were found to have no considerable contribution to the load capacity and the deformation capacity beyond the ultimate load. In other words, for lathe scrap contents of 1-3%, the DDI values increased by 5-23% and the MOT values by 63.5-165% with respect to the reference beam with a stirrup spacing of 270 mm. The influence of the lathe scraps to the DDI and MOT values were rather limited and even sometimes negative for the stirrup spacing values of 160 and 200 mm.

• KIEAE Journal
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• v.15 no.1
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• pp.147-154
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• 2015

Environmental impact assessment techniques have been developed as a result of the worldwide efforts to reduce the environmental impact of global warming. By using the quantification method in the construction industry, it is now possible to manage the greenhouse gas is to systematically evaluate the impact on the environment over the entire construction process. In particular, the proportion of greenhouse gas emissions at the production stage of construction material occupied is high, and efforts are needed in the construction field. In this study, intended for concrete products for the construction materials, by using the LCA evaluation method, we compared the results of environmental impact assessment and carbon emissions of developing products that have been applied low-carbon technologies compared to existing products. As a result, by introducing a raw material of industrial waste, showed carbon reduction. Through a comparison of the carbon emission reduction effect of low-carbon technologies, it is intended to provide academic data for the evaluation of greenhouse gases in the construction sector and the development of low-carbon technologies of the future.

• Journal of the Korean Wood Science and Technology
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• v.26 no.2
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• pp.6-15
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• 1998

A total of forty five-ply, 30- by 30-cm lauan and larch plywood sheets were manufactured in the laboratory using commercial urea and phenol resin adhesives; half of these sheets were treated with fresh concrete. Each sheet was carbonized for 2, 4, and 6hours at $400^{\circ}C$, $600^{\circ}C$, and $750^{\circ}C$, respectively, and their physical properties were measured. The yie1d of charcoal decreased as carbonization temperature and time increased. Charcoal yield was greater in plywood than in veneer, and slightly greater in plywood treated with concrete compared to untreated plywood. Plywood manufactured with phenol resin adhesive had higher pH, higher equilibrium moisture content (EMC), and greater adsorption of methylene-blue dye compared to plywood manufactured with urea resin. For concrete-treated plywood, pH was greater than 10 even when the sheets were carbonized for 2hours at $400^{\circ}C$. Although the EMC of the phenol resin plywood was higher than that of the urea resin plywood, EMC of the phenol resin was lower than that of the urea resin. The larch phenol resin plywood that was carbonized for 6 hours at $750^{\circ}C$ adsorbed more methylene-blue than did the commercia1 wood-based activated charcoal as a result of total pore volume and surface area.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.268-269
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• 2017

Apartment building, which has been accompanied by economic growth in Korea, is a home of life and has the value overlapping as housing and assets. The improvement of consumer's eye level and development of related technology and related service development have positive function that enriches society and creates economic wealth. On the other hand, the clash and conflict between stakeholders increase social unrest and waste our competitiveness by economic loss. The term of warranty liability of apartment building is an important issue of defect lawsuits and is only a few quantitative standards. However, in this study, we examined the revision history of the law and ordinances for the reinforced concrete construction. As a result, establishing and revising the relevant standard, there is no definite basis system to support it. To improve this, the efforts to provide the standard for term of warranty liability and quantitative and objective basis to support it should be accompanied continuously.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.427-437
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• 2013

Generation rate of construction wastes in Korea has occupied preponderantly in recent years. To understand chemical properties of recycled concrete aggregate (RCA), RCA samples were tested for their leaching characteristics. Leaching tests were conducted according to Korean Standard Leaching Test (KLT) and Toxicity Characteristics Leaching Procedure (TCLP) respectively. The RCA samples were characterized using X-ray fluorescence (XRF). Alkalinity of the leachate was determined using a pH meter titration method. The XRF analysis result shows that the calcium oxide (CaO) content in the RCA sample is 25.3~50.4 %. When the RCA sample was mixed with water in a batch reactor, pH in the solution was rapidly increased, and 70% of the total pH change was found in 1 hour. The TCLP showed slightly higher efficiency for leaching heavy metals than the KLT. The leaching efficiency was also higher as the particle size of RCA sample was smaller. The leaching test results suggest that RCA can be generally classified as nonhazardous waste.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.614-618
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• 2006

Recycling of asphalt including shingle is much important for economic aspects such as a decrease of treatment cost. This research was carried out in order to process the recycled shingle to asphalt concrete which is a pavement material. Pure asphalt and the mixture of recycled asphalt were tested in terms of the thermal characteristics, viscosity, and penetration. DSC analysis indicates that the thermal characteristics of separate shingle showed similar properties regardless of processing conditions. Melting of asphalt separated from shingle occurred at $170^{\circ}C$. The viscosity and penetration of the 1~5 wt% of mixed recycling asphalt and raw material asphalt are suitable for the pavement material standard.

• KIEAE Journal
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• v.10 no.6
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• pp.159-165
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• 2010

The composite frame system suggested in this paper consists of steel reinforced concrete beam encased with structural tee and precast concrete column. This system has advantages such as reduction of materials, CO2 emissions and waste. To commercialize the new composite frame system, it is necessary to develop connections that can effectively connect each member. Therefore, a hybrid connection that has steel type connection and reinforced concrete together is utilized to connect easily at the composite frame system. To evaluate the structural performance of the composite frame system, an experimental investigation is presented. In this study, the flexural moment capacity of the composite frame was determined using the strain compatibility approach. The strain compatibility approach can be used to predict the flexural moment capacity at each limit state. As a result, all elements of the beam to column connection are represented to fully interact between each other. The specimens show errors of -1.9% in the yield limit state and 0.9% at the maximum load limit state. Also, testing shows that beam to column connections have characteristics of semi-rigid connection as per Eurocode 3.

• KIEAE Journal
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• v.10 no.6
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• pp.145-151
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• 2010

Bearing wall system was used extensively in most multi-residential apartment buildings in Korea. However, bearing wall apartments have the lack of architectural plan flexibility, remodelling-incompatible, causing serious economic losses in terms of construction waste. Recently, many researchers have studied the use of Rahmen structure as a potential alternative. The beam-column connection in the paper for long-life apartment housing forms connection of a Rahmen structure utilizing the advantages of steel and reinforced concrete. In addition, reduction of cast-in place concrete and construction schedule is expected by using precast concrete. Reduction effect of quantity decreased construction costs and $CO_2$ emission of key construction materials. However, verifying the feasibility of new construction method entails numerous challenges. Accordingly, the purpose of this study is to analyze the construction feasibility of sleeve, coupler, and pressure welding connections for long-life apartment building structure. A 3D modeling software was used to perform the analysis, and a real scale model was created to verify the results of construction feasibility. By verifying the construction feasibility of beam-column connections, this study will contribute to the efficient application of these methods on construction sites.

• Computers and Concrete
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• v.24 no.6
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• pp.555-560
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• 2019

During the application of shotcrete, a part of the concrete bounces back after hitting to the surface, the reinforcement or previously sprayed concrete. This rebound material is definitely not added to the mixture and considered as waste. In this study, a deep neural network model was developed to predict the rebound material during shotcrete application. The factors affecting rebound and the datasets of these parameters were obtained from previous experiments. The Long Short-Term Memory (LSTM) architecture of the proposed deep neural network model was used in accordance with this data set. In the development of the proposed four-tier prediction model, the dataset was divided into 90% training and 10% test. The deep neural network was modeled with 11 dependents 1 independent data by determining the most appropriate hyper parameter values for prediction. Accuracy and error performance in success performance of LSTM model were evaluated over MSE and RMSE. A success of 93.2% was achieved at the end of training of the model and a success of 85.6% in the test. There was a difference of 7.6% between training and test. In the following stage, it is aimed to increase the success rate of the model by increasing the number of data in the data set with synthetic and experimental data. In addition, it is thought that prediction of the amount of rebound during dry-mix shotcrete application will provide economic gain as well as contributing to environmental protection.