• Journal of the Korea Institute of Building Construction
• /
• v.9 no.4
• /
• pp.63-73
• /
• 2009

Recently, the use of lightweight panels in building structures has been increasing. Of the various lightweight panel types, styrofoam sandwich panels are inexpensive and are excellent in terms of their insulation capacity and their constructability. However, sandwich panels that include organic material are quite vulnerable to fire, and thus can numerous casualties in the event of a fire due to the lack of time to vacate and their emission of poisonous gas. On the other hand, lightweight foamed concrete is excellent, both in terms of its insulation ability and its fire resistance, due to its Inner pores. The properties of lightweight concrete is influenced by foaming agent type. Accordingly, this study investigates the insulation properties by foaming agent type, to evaluate the possibility of using light-weight foamed concrete instead of styrene foam. Our research found thatnon-heating zone temperature of lightweight foamed concrete using AP (Aluminum Powder) and FP (animal protein foaming agent) are lower than that of light-weight foamed concrete using AES (alkyl ether lactic acid ester). Lightweight foamed concrete using AES and FP satisfied fire performance requirements of two hours at a foam ratio 50, 100. Lightweight foamed concrete using AP satisfied fire performance requirements of two hours at AP ratio 0.1, 0.15. The insulation properties were better in closed pore foamed concrete by made AP, FP than with open pore foamed concrete made using AES.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.103-104
• /
• 2012

Lately, minimize of the heat loss and fuel consumption when heating so that suggested ways to reduce carbon emissions as a measures to reduce for increase of carbon emission and find a way to apply highly insulated concrete as the measures. In this study, as a comparative experiments on heat conduction of concrete with lots of porous, thermal conductivity of concrete using foamed, polystyrene beads, lightweight aggregates, air-entraining agent and concrete using crushed stone measure and thermal conductivity of concrete with lots of porous compare and evaluate.

• Journal of Animal Environmental Science
• /
• v.4 no.1
• /
• pp.29-36
• /
• 1998

Sawdust is commonly used as a bulking agent for livestock manure composting. Nowadays, demand of sawdust for composting is increasing, so its price is very high and not easy to obtain. In this study in order to examine the effect of autoclaved lightweight concrete (ALC, one of the industrial wastes) on composting of swine manure, ALC (each size of 2, 4, an 8mm) was used as a bulking agent. Swine manure was mixed with each of sawdust and 8mm of ALC in a 1:1 ratio by volume and 2, 4mm of ALC was mixed in a 2:1 ratio by volume. The total period lasted 50 days and was divided into two periods. After mixing bulking agent with swine manure, they were left undisturbed to compost with aeration for an initial period of 20 days. At the end of this period, they were decomposed and mixed to effect a homogenization and then a second period of composting (without aeration) was conducted for 30 days. Temperature during the initial period of swine manure composting were above 70$^{\circ}C$ in all piles and maintained above 55$^{\circ}C$ for 5 days. Temperatures during the second period were relatively lower than the initial period. pH of the compost was increased during the initial period and after 50 days it reached 9.08 in sawdust pile and 9.03 in ALC pile ( 2mm). In nitrogen content of final compost, sawdust pile was higher than ALC piles by 21∼29%.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.297-298
• /
• 2010

This study was investigates to the lightweight foamed concrete are uses by foamed agent to hydrogen peroxide($H_2O_2$). and then, lightweight foamed to improve the physical characteristics were mixed. mixes to type of admixture/level by changes/character to investigates, It is a purpose to look up admixture and mix proportion to be suitable in order to improve lightweight foamed concrete.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.05a
• /
• pp.55-56
• /
• 2015

This study is corroborated as a fundamental resource to develop structural lightweight paste containing silica fume as a part of cement. Paste using foaming agent is generated much foam and decreased density of paste. This study is measured at 0.8% of foaming agent dosage but over 0.8% of foaming agent dosage raise density of paste because of interconnection with foam. Also, FEM analysis using SEM image is confirmed correspondence of between Elastic modulus of experiment and FEM analysis.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.557-560
• /
• 2008

This was done by analyzing the sandwich panels that are now widely used in construction work. Sandwich panels are used for diverse purposes in construction work worldwide. In Korea, polystyrene panels that have organic materials as their core material are used. These panels are thus very vulnerable to fire, with risks of core melting, sheet deformation, and hazardous gases. Accordingly, sandwich panels' fire-resistant or non-flammable properties must be secured. To solve these problems, the optimal mixing proportion of lightweight foamed concrete for the sandwich panel core was determined. A new method of doing this was introduced that is completely different from the existing method, wherein a foaming agent is added to realize lightweight concrete. For lightweight concrete, the foaming mechanisms via diverse chemical reactions were identified, H$_2$O$_2$ was added for heating in the reaction, and the concrete foaming was maximized. Through diverse experiments to determine the optimal mixing proportion of lightweight foamed concrete and to examine the filling characteristic of lightweight foamed concrete for sandwich panel cores using waste materials, the physical and mechanical properties of lightweight foamed concrete were examined.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.207-210
• /
• 1998

Providing the connectivity interworking between the lightweight signaling function using in VOD set-top box and the broadband signaling function In the access node system, it can diminish the cost-burden of user about set-top box and we shall use efficiently the network resources. Therefore, In this paper, we shall design the signaling brokerage agent function for the connectivityinterworking in access node system and discuss the result applied its function to the real-time VOD service.

• Journal of the Society of Disaster Information
• /
• v.8 no.3
• /
• pp.204-212
• /
• 2012

Lightweight soils are very economical and environment friendly materials that are valuable in field without wasting construction materials, dredged soils and clay/ silty soils during construction. Recently, the research of lightweight soils mixed with recycled material (recycled tire powder, rice husks) have been investigated. In this study the mix design factors (i.e., weight of soil, water content, foaming agent and added water) were analyzed and optimized mix design was suggested using cement content for revealing strength. For the analysis the stress-strain behavior, strength with respect to time, and experimental strength for the component of recycled material were analyzed. Finally, target strength was determined to calculate reasonable and economical mix ratio and the optimized cement content was suggested.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.43-44
• /
• 2023

Fire doors installed to prevent the spread of fire in buildings are made of paper honeycomb, glass wool, and other materials. Due to their high water absorption rate, they absorb ambient moisture and degrade, and their increased weight causes them to sag internally, creating voids that can warp in the event of a fire and allow flames to pass through. To overcome these issues, research is being conducted on the physical performance of lightweight aerated concrete. However, there is a lack of research on how to ensure fire resistance. Therefore, in this study, the backside temperature of lightweight aerated concrete formulations was measured and compared and analyzied with the physical performance. Since it is difficult to achieve low density by saturation alone, aerated concrete with EPS was produced, which resulted in a density reduction of 24'26%, but the strength increase per unit cement increase was 5'25%, which tended to be lower than the formulation without EPS. The results showed that the lightweight aerated concrete with EPS was 130~140℃ lower than the lightweight aerated concrete with EPS, which is believed to be due to the melting point of EPS delayed the heat diffusion. In the future, wo plan to conduct research to identify the optimal formulation for fire door core materials by varying the amount of EPS added and using industrial by-products to increase long-term strength.

• Journal of the Korea Institute of Building Construction
• /
• v.9 no.5
• /
• pp.63-70
• /
• 2009

This study is part of an ongoing research project on the development of a sound-absorbing lightweight foamed concrete manufactured by a hydro-thermal reaction between silica and calcium. As the silica source, pulverized bottom ash was used, and as several cementitious powders of ordinary portland cement, alumina cement and calcium hydroxide were used. Manufacture of foamed concrete was accomplished using the pre-foaming method to make a continuous pore system, which is the method of making the foam by using a foaming agent, then making the slurry by mixing the foam, water, and powders. The experiment factors are W/B, foam agent dilution ratio, and foam ratio, and test items are compressive strength, dry density, void ratio, and absorption rate, as evaluated by NRC. The experiment results showed that the sound absorption of lightweight foamed concrete satisfied NRC requirements for the absorbing materials in most of the experiments. It is thus concluded that foam ratio was the most dominant factor, and significantly affected all properties of lightweight foamed concrete in this study. W/B rarely affected total void ratio and continuous void ratio as well as compressive strength, and dry density and foam agent dilution ratio also had little effect onalmost all properties. The analysis of the correlation between NRC, absorption time, continuous void ratio, and absorption time showed that the interrelationship of the continuous void ratio was high.