• KIEAE Journal
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• v.6 no.1
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• pp.11-16
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• 2006

This paper deals with the experimental for manufacturing the lightweight buildng materials with portland cement, fly ash, slag, lime, gypsum, and aluminum powder system. Aluminum powder was added an aerating agent. Specific gravity range of lightweight concrete specimens were 0.6~0.9g/cm3. These specimens properties studied by means of specific gravity, compressive strength, absorption coefficient, transmission loss and scanning electron microscopy. Cellular concrete with maximum compressive strength was 41kgf/cm2 by obtained Al=0.05wt.%. Moreover, the aeration lightweight concrete showed excellent sound absorption properties.

• KIEAE Journal
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• v.7 no.1
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• pp.73-80
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• 2007

This paper aims to develop the diffused reflection material in order to reduce the solar absorption coefficient, and to compare the thermal properties with the different roof structure system; one is using the diffused reflection material applied the upper side of the rigid sheet waterproof system and the other is using the conventional up-side down waterproof system on the roof. For this purpose two experimental test boxes were made of same iso-panel wall and floor with different roof system. The experiment was carried out under these process; measure the surface temperature exposed solar radiation of the variation of the reflection materials(cement paste, silica, galvanized steel and titanium dioxide(TiO2)), measure and analyze the variation of the temperature distribution of the each roof system and indoor air in order to evaluate the thermal properties according to the different roof system. The result shows clearly that using the titanium dioxide(TiO2) might be more effective to reduce the solar insolation.

• KIEAE Journal
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• v.7 no.3
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• pp.57-62
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• 2007

Most of current building materials are made of organic compounds or at least made with chemical treatments. Though easy to use and comparatively pay less, those materials are generally not enviornmentally sound. VOC is one of harmful effects. On contrary, natural materials such as soil are usually eco-friendly, and environmentally sustainable as well if not treated in autoclaves. Acoustica materials made of such environmentally sound and sustainable could be widely used. It is aimed to prove that soil based materials could be effectively used in acoustical fields rather than the other usual materials. Experiments with various types of soil blocks and soil plaster were performed. It is proved that the soil plaster has better apsorption features than cement plaster. Soil blocks have higher absorption cofficients than soil plaster, due to the thickness, and the absorption characteristics can be controlled by the design of the blocks.

• The Korean Journal of Zoology
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• v.26 no.2
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• pp.135-153
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• 1983

Studies of fouling organisms in Deukryang Bay in 1981 showed that amphipod crustaceans comprised the most abundant zoological group. Three tubicolous gammaridean amphipods, Jassa falcata (Montagu, 1808) Corophium acherusicum (Costa, 1857) and Ericthonius brasiliensis (Dana, 1853) were described. They formed great masses of silty tubes attached to plastic and cement experimental plates. The ecological aspects of these fouling organisms have been also discussed.

• KIEAE Journal
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• v.10 no.5
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• pp.123-129
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• 2010

This study aimed at analyzing the trend of carbon dioxide emission for direct and indirect areas by using inter industry relations table between 2000, 2003 and 2005 in the key building materials and components. Results of this study are as follows; First, the material and components for this study was selected in 20 industries of products such as sand, gravel, cement, concrete articles, rebar, and steel bar. Second, among the 20 selected key building materials, the group with the highest carbon-dioxide emission was shown in ready-mixed concrete, concrete articles, and primary aluminum goods. Third, as a result of analyzing the changes to the units of carbon dioxide emission according to passage of time, the number of items which is changed in such as sustained increase or decrease over time was insignificant in carbon-emission change trend.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.6
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• pp.264-270
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• 2008

Ecological lightweight aggregates were made by using the wastes come from various industrial fields. Wastes were crushed and pulverized by mills and a certain portions of wastes were mixed and formed by pelletizer like small beads. The formed lightweight aggregates were finally sintered with $1125^{\circ}C$/15 min conditions by using rotary kiln. Lightweight concrete sound absorbers were made of ecological lightweight aggregates K73 (Coal bottom ash 70 wt%: Dredged soil 30 wt%) and K631 (Clay 60 wt%: Stone sludge 30 wt%: Spent bleaching clay 10 wt%). For the reference, lightweight concrete sound absorbers made of DL (German made 'L' company LWA) were also made under the same conditions. Sound absorption characteristics were observed and measured according to the kinds of aggregates, water/cement ratio (W/C=20, 25, and 30%), and designed pore rates (V=20, 25, and 30%). The pore rates of the lightweight concrete sound absorber were turned out to be 5 to 10% higher than designed ones. Absorption coefficient of the lightweight concrete sound absorber by using K631 aggregates with W/C=20% and V=25% conditions was 0.88 at 1000 and 3150 Hz from the measurement by the impedance tube.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.57-68
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• 2010

The purpose of this study is to analyze the characteristics of environment-friendliness of waterproof materials based on comprehensive experiments on waterproofness in terms of coefficients of permeability, harmfulness of waterproof materials and fish toxicity of Oryzias latipes mortality to verify eco-toxicity of each method of construction and waterproof material, which are to be applied by taking eco-toxicity into account when building ecological flows in upper areas on natural and artificial grounds. As a result, the following conclusions have been reached in this study: 1. In regard of the harmfulness analyzed, each material showed a different result of analytical value in each lab tank. Compared to input water, pH, COD, SS, T-P, and T-N values increased a little, but DO value decreased. The value of turbidity analyzed independent of the water quality standard of aquatic ecosystem set forth by the Ministry of Environment increased a little compared to the value in input water. 2. In the experiment of fish toxicity, compacted quicklime, cement fluid waterproof material, cement mortar waterproof material and bentonite powder were found to have 100% of fish mortality, respectively, and membrane waterproof material showed 83.3% of mortality, indicating strong fish toxicity. Improved asphalt sheet (63.3%) and synthetic rubber sheet (53.3%) were analyzed to have medium fish toxicity, while bentonite sheet (6.7%), Hwang-toh (6.7%) and clay (3.3%) showed relatively lower mortality and fish toxicity. 3. Regarding the analysis on waterproofness in terms of the coefficient of permeability of each waterproof material, improved asphalt sheet, synthetic rubber sheet, membrane waterproof material, cement fluid and mortar waterproof material and bentonite sheet were found impervious in case no leakage takes place in construction. Bentonite powder was found practically impervious based on the analytical results from the experiment done in compliance with weight ratios. So were the clay and Hwang-toh from the experimental results. To sum up such results as found in the experiment mentioned so far, the values of harmfulness and waterproofness analyzed were different in each lab tank, but there was absolutely little correlation with the mortality gained from the experiment on fish toxicity. In the experiment of fish toxicity, environment-friendly waterproof materials were analyzed, and it was found that clay, Hwang-toh and bentonite sheet are highly environment-friendly. In contrast, synthetic rubber and improved asphalt sheets were found to have medium-level environment-friendliness. Also, membrane water-proof materials, compacted quicklime, cement fluid and mortar waterproof material and bentonite powder were analyzed to have low environment-friendliness.

• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.61-69
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• 2007

The building materials used for improving indoor air quality, the wood charcoal mixed with cement mortar or natural water paint were examined for their potential removing ability of formaldehyde. After the reaction of samples with formaldehyde in the glass flasks designed in our lab, the remaining formaldehyde was collected using DNPH (2,4-dinitrophenyl hydrazine) cartridges, and their concentration was determined using HPLC. From the results, it was found that the removing amount of formaldehyde per one gram sample containing 5, 10, or 15% of wood charcoal was more than three times compared to that of control (100% cement mortar or water paint). Their elimination percentages from the initial formaldehyde was about 80~90%. The experimental results for wood charcoal-water paint showed a similar trend with those of wood charcoal-cement mortar samples. Their elimination percentages from the initial formaldehyde was about 90%. It is proposed that formaldehyde is adsorbed on the adsorbed 'O' or 'OH' groups in the graphene layers formed through the re-arrangement of lignocellulose in the wood during the carbonization procedure.

• Journal of the Korean Wood Science and Technology
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• v.37 no.6
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• pp.537-545
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• 2009

The objective of this study was to investigate potential usage of environmentally friendly building materials, liquid mortar and dry cement mortar mixed with charcoal, based on the test of their physical and chemical properties. From the test results of physical and chemical properties of the liquid mortar mixed with charcoal, liquid mortar containing over 20% of charcoal, the consistency viscosity and the non-volatile content met a standard requirement. Drying time was delayed with increase in charcoal contents in the liquid mortar, however they were fully cured within 60 minutes in all treated levels. Other properties were acceptable at standard requirement. From the results, it was found that the proper charcoal addition level to the liquid mortar was 25%. In the results on dry cement, it was found that samples containing 5% of charcoal showed the maximum compressive strength, whereas samples containing over 20% of charcoal did not reach the minimum requirement of KS standard. Water retention ability constantly increased as the charcoal ratio increased. The conventional dry cement mortar adsorbed 59.5% of it, in the test of adsorption rate on ammonia gas, whereas cement mortar containing 10% of charcoal showed 71.6% of ammonia gas adsorption.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.112-119
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• 2020

In this study, cellulose-based bacterial pellets was used for the self-healing concrete manufacturing. The pellet is composed of complex cultured bacterial spore powder, methyl cellulose, two kinds of PVA nutrients and water, and is extruded through a hydraulic press to have a shape of 2mm in diameter to 3 to 4mm in length. Cellulose pellets expand at neutral pH, release bacteria and nutrients, and do not react in a basic environment, increasing the long-term survival rate of bacteria in cement mortar. In addition, pellet self-healing performance of pellet mortar was significantly higher than that of control mortar. Cellulose-based pellets are a new type of bacterial carrier system that will help develop self-healing concrete in the future by improving and optimizing pellets.