• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.38-45
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• 1999

The 2-trowel type concrete floor finishing robot can move in any direction by adjusting the posture or trowels without any wheels. Since the quality of the smoothed and polished concrete floor is determined by plastering speed, we need to control the velocity of the robot. However, we cannot use the typical motion control method because it is very difficult to measure the velocity of the robot, in contrast to the mobile robots with wheels. To overcome this difficulty, the following are studied in this paper: we found that the robot dynamics has the disturbance depending on its translational speed, and showed that there exists the saturated velocity of the robot which is set by the posture of the trowels, and obtained the relationship between the saturated velocity and the posture in the translation. The result enables us to control the motion of the robot only by adjusting the posture of trowels without measuring the velocity of the robot. Currently, we built the troweling robot and are experimenting its performance with the proposed motion control method.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.83-87
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• 1995

Impact-bouncing height of steel balls dropped from 1m height on various floor materials were measured to evaluate impact-bouncing characteristics depending on floor materials and the effect of these properties on walkability and fatigue of humanbody. Stone and tile finished concrete floor showed the highest bouncing height of around 70%, and soil showed the lowest bouncing height of around 3%. The second highest bouncing height was about 40% which corresponded to terazo finished concrete floor and about twice as high as the bouncing height on concrete floor without finishing. The impact-bouncing height could be lowered to 15~20% by using gum tile on concrete floor. Steel showed similar bouncing height to concrete floor, and wood-based materials showed the second lowest bouncing height next to soil. Among wood-based materials, hardwood species having higher specific gravities showed relatively high bouncing height of 8~24%, softwood species having low specific gravities showed relatively lower bouncing height of 5~18%, and wood composites showed bouncing height of 8~18%. Among all the materials used in this study, wood-based floor materials corresponded to the bouncing height of 10~15% which is considered to be best for humanbody. Surface painting on wood-based materials increased the bouncing height, and the number of bouncing of steel balls after dropping from 1m height increased as the bouncing height increased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.153-156
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• 2009

This study investigated the fundamental properties corresponding to various length changes on NY fiber reinforced concrete. For results of fresh concrete, the slump and air content were declined, but the unit volume weight and vebe time were increased. For the hardened concrete properties, the compressive strength showed increasing tendency according to the NY fiber length. The dry and autogenous shrinkage also decreased compared with Plain. Generally, the caes that 19 mm NY fiber was used was better than any other cases.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.953-958
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• 2002

The finishing method of concrete floor using automatic surface finisher is one of new technologies in concrete floor construction. The development of high technologies in construction will increase in order to satisfy the demand to construct high quality building. Using this method, it is possible to increase the quality of building as well as to reduce the labor work in site. In this paper, a system which can be used to finish the concrete floor using automatic surface finisher, is presented and its structural capacities are evaluated. The system is composed of rail which guides the surface vibrator and absorbs the volume change of concrete, and a device supporting the rail. From the experimental work for these devices, it was shown that the support and rail had suitable strength to resist the automatic surface finisher. For design purpose, also, effective span of supports was tabulated.

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.165-172
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• 2012

This study was designed to determine the effect of different floor space and type of finishing building on performance, behaviour and carcass quality of finishing pig. Three hundred and thirty six finishing pigs were alloted into two space allowance ($1.0m^2$and $2.5m^2$/pig) and two floor type (concrete slat and bedded with sawdust) of finishing building. There was no significant difference between the different space allowance in the body gain, feed intake and feed per gain. And also floor type of finishing building was not affected by the performance of finishing pig. Space allowance per pig affected the maintenance behaviour, but there was no significant difference between the floor type of finishing building in the spent time on lying, sitting and standing. Floor type was affected by the occurrence of standing behaviour, the finishing pigs in the bedded with sawdust showed less occurrence of standing. Carcass traits did not show any significant difference due to the difference of space allowance and floor type of finishing building. There was no significant difference in the chemical compositions of pork loin between the space allowance and floor type of finishing building.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.175-180
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• 1999

The heating system of korea apartment house is called Ondol. The surface finishing mortar of this floor system typically used the cement based mortar, where the surface finishing mortar easily appears the crack. To order to crack control, the cement that added expansive additive used to reducing dry-shrinkage. For the surface finishing mortar, the types of shrinkage is known as plastic shrinkage, dry-shrinkage and autogenous This experimental study is to investigate the difference on dry-shrinkage of the cement that added expansive additives and OPC. The test method is varied the ration of water/cement (W/C) and the ratio of sand/cement(S/C). For OPC, The increase of the ratio of S/C is reduced dry-shirnkage but for the cement that added expansive additives, the increase of the ratio of S/C is augmented dry-shrinkage For OPC, The increase of the ratio of W/C is augmented dry-shrinkage but for the cement that added expensive, the increased of the ratio of W/C is reduced dry-shrinkage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.177-180
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• 2012

Korea residential housing generally use wet floor heating system 'Ondol' which consist of insulation cushioning, lightweight foamed concrete, hot water pipe and mortar on top of reinforced concrete slab. Wet floor heating system's installation process is too complicate and difficult to supervise field for continuing assurance quality. Also, this method has a huge impact on the progress of construction because it take a long time to cure finishing mortar and lightweight foamed concrete. Therefore, it is considered a disturbance factor of reduction of construction duration for enhancing competitiveness. In this study, we conducted an experiment about the radiant heat performance and temperature difference on upper panel of rolled dry floor heating systems which is jointly developed by Kolon global and Sumisho Metalex for remodeling housing, studio apartment and the urban-life housing.

• Journal of the Korea Institute of Building Construction
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• v.7 no.2 s.24
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• pp.99-106
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• 2007

The purpose of this study presents in Relations between cracks in self-leveling material and quality of floor groundwork surface are experimentally examined. As the first stage, the experiment to observe cracks in self-leveling material constructed on floor groundwork made from various kinds of concrete was carried. As a result, following basic findings were obtained. First, observation of cracks should be continued until an increase in width of cracks stop, without constructing any finishing material. Second, degree of cracks may be indicated quantitatively by the product of length and width. Finally, Cracks and separation is not be influenced by specimen size. Based on these findings, the method of predicting cracks by evaluating surface layer quality of floor groundwork will be established.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.265-266
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• 2014

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.5
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• pp.414-422
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• 2013

As structure-borne sound, the floor impact sound is one of the serious noises in residential building. Most of heating system applied to the typical Korean residential building is floor heating system which is called ondol. The ondol usually consists of finishing material, mortar with heating coil, light-weight aerated concrete and reinforced concrete. This study focused on the isolation of heavy-weight impact sound and modification of mortar and light-weight aerated concrete. Specifically the glass foam aggregate was added on light-weight aerated concrete. Also, water-cement ratio and amount of cement on mortar were revised. The sound pressure level of heavy-weight impact was measured in reverberation chamber using both bang-machine and impact ball. The size of specimen was 1 m by 1 m. Substitution ratio of glass foam aggregate on light-weight aerated concrete shows relationship with heavy-weight impact sound pressure level. In addition, heavy-weight impact sound pressure level was decreased with increment of water-cement ratio and amount of cement on mortar.