• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.1231-1238
• /
• 2010

Recently, the utilization of recycled aggregates for backfilling a power transmission pipeline trench has been increasing due to the issues of eco-friendly construction and shortage of natural aggregate resource. It is important to investigate the physical and thermal properties of the recycled aggregates that can be used as a backfill material. This study presents the thermal properties of two types of recycled aggregates with various particle size distributions. The thermal properties of the recycled aggregate were measured using the transient hot wire method and the probe method after performing the standard compaction test using an automatic compactor. Similar to silica sand, the thermal resistivity of the recycled aggregates decreased when the water content increased. This study shows that the recycled aggregate can be a promising backfill material substituting for natural aggregate when backfilling the power transmission pipeline trench.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.961-966
• /
• 2007

Recently the regulation related the environment is getting more and more strengthened. Needs for sustainable building is growing more and more interested in construction industry. However, most of the research has been conducted is focused on material production or maintaining phases. There are not enough research especially in construction phase. And it still exists a lot of environmental barrier factor which could not be easily quantified in construction fields. It makes problems that contractors make an effort only an adequate regulation and they does not take an interest in reducing efforts of environmental pollution. This research defines factor categories which have to be mainly managed and provides the integrated construction management method for sustainable building to reduce environmental pollution through analysis of environmental barrier factor in each work package and effective adjustment of construction plan.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.11a
• /
• pp.143-144
• /
• 2019

Recently, environmental pollution related to global warming is on the rise. Meanwhile, renewable energy is a representative example of many efforts to develop eco-friendly energy to solve the depletion of natural resources and the depletion of petroleum resources in conjunction with global warming. Among them, photovoltaic power generation is increasing the subsidies for the government to increase the production of photovoltaic electricity of the general public, showing a high growth rate. However, polysilicon, which is a raw material of the photovoltaic panel, generates waste called polysilicon sludge in the manufacturing process. In order to produce 1 ton of polysilicon, about 2 tons of waste polysilicon sludge is generated. In 2012, polysilicon sludge was generated at 78,000 tons, with an average of about 220 tons per day. The sludge generated due to insufficient treatment of polysilicon sludge is currently solidified and is processed by landfilling. Therefore, in this study, polysilicone sludge is used as the concept of admixture, and the physical properties of the matrix according to the polysilicon sludge replacement ratio based on light burned magnesia is determined.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.159-160
• /
• 2023

Recently, interest in reducing cement has been growing. Hwangto, an eco-friendly material, has advantages such as air purification effect and humidity control, but when used, accidents such as form collapse may occur due to low strength and reduced durability. In order to quantitatively evaluate the timing of mold demolding, we would like to evaluate the timing of mold demolding through correlation with compressive strength using ultrasonic pulse velocity. As a result, the time at which 5 MPa is developed is after 20 hours for the test specimen of W/B 41 , in the case of W/B 33, NC33 and HTC33-15 were equally expressed at 12 hours, and HTC33-30 was expressed at 16 hours.

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.2
• /
• pp.109-115
• /
• 2018

Since the current method of SCW cement milk pouring method uses one to one ratio of cement milk with OPC, there are some problems such as drying shrinkage, increased cost, difficulty of controlling mix proportions for various conditions of applied soil, and precipitation of $Cr^{6+}$ due to the excessively used cement. Specifically, in aspect of sustainability issues of cement manufacturing, the consumption of cement should be reduced. Hence, in this research, as a replacement of cement for SCW method, blast furnace slag with sulfate or alkali as a stimulant, and expansive admixture were used. By using blast furnace slag as a hardening composite of SCW, there are many advantages such as free controllable mix proportions, rapid setting time with less mud occurrence, less cost with less energy for mixing, constant strength development, and less precipitation of $Cr^{6+}$. Regarding the alternative composites for SCW, in this research, durability and chloride resistance were evaluated.

• Journal of the Korean housing association
• /
• v.25 no.4
• /
• pp.39-46
• /
• 2014

This research was for the investigation and analysis of the illustration of modular construction application which is different use by each school facility since modular construction related examples are rare in domestic situation, and it has a limitation because of its being basic research material for generating the basic form of modular construction. The research results are as followings. First, in case of school facility from illustration investigation results, module measurement of class modulation is as similar as $3m{\times}10m$, but in resident facility the planning of more flexible plane shape can be possible since modules of 6 cases are free and various, and facade form of various types can be appeared by combination of module unit. Second, as a result of the generated characteristics in compared analysis of representative examples, school facilities were highly indicated for movability and duration reduction areas, and the flexibility, economic efficiency, and environment-friendliness was indicated low relatively. Third, the basic planning types of modular construction can be largely divided into layered type, horizontal (straightway) type, and compound type. The layered type has a short traffic line and facility system and is appropriate for the low-rise form unless separate construction method is used since it is susceptible to load. The horizontal type is advantageous for securing an opening since it has wide extent in light but has a long traffic line and facility system. Finally, the compound type can be possible for planning of various forms but needs the combination of various unit modules and traffic line and facility plan for it can be difficult.

• Microbiology and Biotechnology Letters
• /
• v.40 no.3
• /
• pp.169-179
• /
• 2012

Microbiological calcium carbonate precipitation (MCCP) is being applied for the aesthetic restoration of cement buildings destroyed by biochemical processes and to block water penetration into the cement's inner structure. After determining the advantages of this technique, many related studies in the area of architecture concerning the application of microorganisms to improve construction material have been reported in both America and Europe. The techniques compatibility with cement material is especially interesting because of the needed screening of various calcium carbonate forming-bacteria and the required development of their application methods. The purpose of this review is to describe the mechanism of MCCP and related researches with eco-friendly construction materials. Mainly, we describe the methodological studies focused on biodeposition on the surface of building materials and the research trends concerning the addition of microorganisms to improve the durability of cement structures. Additionally, the concepts and technical aspects focused on the development of self-healing smart concrete, with the use of multi-functional bacteria, have been considered.

• Journal of Korean Society of Forest Science
• /
• v.100 no.2
• /
• pp.283-291
• /
• 2011

The purpose of this study was to identify the public's preferences of different types of debris barriers and the impacts of construction materials, design, size, and planting on landscape preferences. On-site survey was carried out in Mt. Palgong during on December, 2009 and a total 122 visitors' data were analyzed. A total of 82 students Yeungnam and Donga University were also questioned in the classes during on December, 2009. Survey results showed that the debris barrier constructed with natural materials such as stone were more preferred and the level of planting around the debris barrier impacted most on the landscape preferences. The results imply that the importance of eco-friendly construction materials and methods has been increased in term of not only environmental conservation but also people's preferences. Therefore, the factors for enhancing landscape of debris barrier should be considered synthetically in terms of construction material, design, size, and planting level.

• Journal of the Korea Concrete Institute
• /
• v.23 no.3
• /
• pp.331-338
• /
• 2011

The purpose of this study is to use organisms or micro-organism functions for eco-friendly water-purification of cement bricks, utilizing bioremediation. Many researches have been performed in the past to improve water quality by using effective micro-organisms in construction materials. In order to purify water using micro-organisms, this research used soybean paste bacteria, an effective micro-organism that was identified through 16S rDNA sequence analysis performed in Daegu S. Environment Protection Institute in addition to Natto bacteria that was studied in the previous research. With these effective micro-organisms with water-purification ability, this study examined their water-purification possibility on cement bricks. This study used Zeolite to immobilize micro-organisms to bricks, and confirmed that the micro-organisms were attached on Zeolite from SEM analysis. The experimental results showed that specific micro-organisms can be used to effectively remove contamination an used to develop eco-friendly construction materials. The study on micro-organisms for material purification shows great promises as a future research topic.

• Advances in concrete construction
• /
• v.9 no.3
• /
• pp.279-287
• /
• 2020

This paper focuses on the engineering properties of Bentonite-Cement-Sodium silicate (BCS) grout, which was prepared by partially replacing the ordinary Portland cement in Cement-Sodium silicate grout with lithium bentonite (Li-bent) and sodium bentonite (Na-bent), respectively. The effect of different Water-to-Solid ratio (W/S) and various replacement percentages of bentonite on the apparent viscosity, bleeding, setting time, and early compressive strength of BCS grout were investigated. The XRD method was used to detect its hydration products. The results showed that both bentonites played a positive role in the stability of BCS grout, increased its apparent viscosity. Na-bent prolonged the setting time of BCS, while 5% of Li-bent shortened the setting time of BCS. The XRD analysis indicated that the hydration products between the mixture containing Na-bent and Li-bent did not differ much. Using bentonite as supplementary cementitious material (SCM) to replace partial cement is a promising way to cut down on carbon dioxide emissions and to produce low-cost, eco-friendly, non-toxic, and water-resistant grout. In addition, Li-bent was superior to Na-bent in improving the strength and the thickening of BCS grouts.