• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.304-310
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• 2018

The aim of the research is to provide possibility of quality controlling by rheological properties for lightweight foamed concrete. The lightweight foamed concrete achieves its low density by containing air bubbles (foam) produced during the mixing process. Therefore, containing foamed volume during setting period is critical for the securing the performance as an insulating material. In this research, regarding foam collapse during the setting period, rheolgocial properties of fresh state lightweight foamed concrete were assessed to get its relationship with volume stability, or foam stability. For the experiment regarding foaming factors including mixing time, mix design of contents for materials, rheological properties of fresh state lightweight foamed concrete were tested with its density and settling depth. Based on the settling depth with various factors, relationship with rheological properties was analyzed, and especially, close relationship of plastic viscosity and settling depth was found. Therefore, from the results of this research, it is considered to contribute on suggesting a new approach of quality controlling for lightweight foamed concrete using rheological test method.

• Journal of the Korea Institute of Building Construction
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• v.7 no.2 s.24
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• pp.77-83
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• 2007

This study investigated the fundamental properties of the lightweight foamed concrete depending on various admixtures, and the results were summarized as following. When 20% of cement kiln dust(CKD) and 0.002% of stabilizing agent were mixed to lightweight foamed concrete, it was necessary to use a superplasticizer because flowability was decreased. However, it could reduce sinking depth which were the extensive trouble of lightweight foamed concrete. Bulk density was divided into '0.4' and '0.5' grades on KS according to unit volume weight. The compressive strength was less than that of plain concrete when admixtures were applied, but the results exceeded the minimum strength of the each grades on KS. Totally, it is found that the combination of 20% of CKD and 0.002% of stabilizing agent makes it possible to reduce a sinking depth, recycle resources, and save cost when were mixed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.237-239
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• 2011

This study was performed to investigate the influence of curing temperature on the properties of light weight foamed concrete, manufactured on-site construction according to the various experimental factor such as temperature of material, curing temperature in air(5, 10, 20℃), curing time in air(5, 10, 15hour), and target density of hardened state(0.8, 1.2t/㎥). As a result, the influence of the curing temperature on various properties of foamed concrete is greater than curing time. When increasing temperature and time in air curing, progress of hydration is fast and compressive strength is increasing more and more. However, when considering the productivity, minimum curing time is required 15hours at 5℃, 10hours at 10℃, and 5hours at 20℃. If this condition is not required, there is some crack due to volume expansion on the surface of light weight foamed concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.77-78
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• 2019

Organic insulating materials can cause fatal toxic gases when burned, which can lead to human injury. As a combustible material, the risk of fire spreading is great. Therefore, there is a need for a study on the lightweight cured body for the non-combustible inorganic insulation to replace the flammable organic insulation. This study aims to examine the properties of lightweight foamed concrete according to the dilution concentration of animal foaming agent which forms a closed void when foaming as a part of the experiment to examine the utility of the lightweight foamed concrete as an insulating material. Bubbles occupy a large volume of lightweight foam concrete and have a great influence on the properties. Therefore, the stability of the bubble is very important, and as a result of the experiment, it is determined that 3% of the smallest vesicles are prepared at the proper dilution concentration.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.151-158
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• 2011

Bubbles within the foamed concrete manufactured by pre-foaming method is the main factor which affects the physical properties of foamed concrete such as density, strength, and porosity. Although many researches on foamed concrete have been continuously carried out, insufficient number of researches on the properties related to bubbles in the foamed concrete has been performed except for chemical application related researches. In order to make an optimal foamed concrete, study on the bubble properties must be pursued. In order to effectively implement bubbles in the manufacturing of foamed concrete, the bubble properties must be estimated. In this study, in order to determine the bubble properties, examination of the bubble properties according to types and foaming agent concentration was performed. An foaming agent used for this test were anionic surfactant, rosin, and protein system with the foaming agent concentration range of 0.05~13%. Test parameters considered in the study were foaming rate, foam volume, drainage solution volume, and bubble size. The study results showed that, regardless of foaming agent type, higher concentration of foaming agent showed an increase in the foaming rate. Also, the results showed that concentration of foaming agent affected bubble size, drainage solution volume change, and bubble distributions. With respect to the stability of the bubble, protein foaming agent was better than anion surfactant or rosin foaming agent. With respect to the bubble shape, anion surfactant and rosin formed bubbles had polygon shape where as protein formed bubbles had spherical shape.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.132-133
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• 2014

In this study, high volume of industrial by-products including blast furnace slag, recycled aggregate powder and incineration ash have been utilized on the slurry of the foamed lightweight concrete. As to decrease the price of the lightweight foam concrete, mortar based slurry and concrete based slurry has been fixed. As the variation of the foam conduction ratio and aggregates, the foam ratio and compressive strength has been tested. Results showed that using recycled aggregates in the slurry showed better effect than using natural aggregates due to the alkali properties of the recycled aggregates could activate the potential hydraulic properties of the blast furnace slag. Consider about the low price of the recycled aggregates, it could be identified that using recycled aggregates in high volume blast furnace slag blended lightweight concrete showed better compressive strength than natural aggregates.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.69-72
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• 2009

This research is focused on the applying of the foaming agent which can make the independent pore in the concrete structure in order to make a lightweight concrete structure. This lightweight foamed concrete can satisfy both the required strength and the mechanical properties as structural members. In addition, anti freezing-thawing properties also required. As a result of the unit volume-weight measurement, when the foaming agent mixed at 0.5% to 1%, the lightweight foamed concrete can be applied for the structural member. Also the density and compressive strength measurement results reveals that it will be suitable as structural member with 21MPa strength, when the density is betweenity8 to 1.9 and foaming agent quantities are 0.5% to 1%. Finally the result of freezing-thawing experiment, the effect freezing-thawing damage reduced according to adding foaming agent because those foaming agent make micro-pores in the structure which are not seen in the ordinary concrete structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.52-53
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• 2018

In this study, viscosity analysis of the lightweight foamed mortar was conducted to evaluate the foam stability. According to a series of experiment, void volume related with density of the mixture and viscosity of the mixture were infleunced by water-to-binder ratio and addition of viscosity modifying admixture (VMA). Especially, the stability of the foam inside the mortar was confirmed with adding VMA.

• Journal of the Korean GEO-environmental Society
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• v.11 no.4
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• pp.33-42
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• 2010

The lightweight foamed concrete is used to reduce the weight of the backfill material. When it is applied, the volume is often contracted due to segregation, necessitating re-injection. In this study, it was manufactured a new lightweight foamed concrete by adding plasticizer and tested the engineering properties of the material. The tests included unconfined compressive strength test, unit weight test, flow test, pH test, and permeability test. The plasticizer is shown to have an important influence on the flow. It was shown that 2~2.4% of plasticizer was adequate. The new material was shown to have positive influence on the flow and reduction of weight when applied to the backfill of the structures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.335-340
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• 2001

We use so many plastic products in everyday. Because polymer materials have a lot of merits including low cost and easiness of forming, they are widely used in many manufacturing industries. Microcellular foaming process was developed at MIT in 1980's to save a quantity of materials and increase mechanical properties. The improvement of strength is very important factor in relation with the reduction of mass. So the first purpose of this research is to improve the strength of the microcellular foamed plastics as variation of glass-fiber's volume friction. Also the characteristic of filler such as glass-fiber was presented in a microcellular foaming process.