• Journal of the Korea Institute of Building Construction
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• v.21 no.1
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• pp.11-19
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• 2021

The aim of the research is providing a fundamental data on quality and constructability of direct tile setting method depending on various cement to sand ratio for tiling dry cement mortar. A large number of tile setting failures reported is related with the cement mortar and its construction for tiling. Because of different materials of tiles, the properties of tiling dry cement mortar, an adhesive for tiling, can influence on quality and constructability of tiling differently. Practically, the easiest way of controlling the properties of the tiling dry cement mortar is to control the proportion of cement and sand. Hence, in this research, sand to cement ratio (S/C) was controlled. Since there is no standarized method on evaluating performance of dry cement mortar for tiling, a several sensory evaluation methods were suggested and executed. According to the experiments conducted in this research, the adhesive performance of cement mortar for tiles can be different depending on the sides such as tile and substrate. Additionally, depending on S/C, finishability, initial adhesive performance, and tile shifting resistance can be changed for ceramic tile. Therefore, under the conditions of this research, about 5 of S/C can be recommended for appropriate performace of tiling dry cement mortar.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1128-1135
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• 2019

In this study, different types of polyether amines and H₁₂MDI were used to synthesize water dispersed urea resins, which can be applied to coating material on the concrete slabs for bicycle road using the ordinary application equipments. The concentrations of several polyether amines with different molecular weights and the number of amine functionality were varied to set up the optimal condition for water dispersed urea resin preparation with both an excellent tensile strength and an elongation. In addition, the effect of DMPA[2,2-Bis(hydroxymethyl)propanoic acid] concentration on the storage stability of the water dispersed urea resin was also investigated. The formation of urea bonds from isocyanate and polyether amines was confirmed through FT-IR ATR spectroscopy. From the mechanical properties of urea resins, PU-4 and PU-6, which were prepared with both diamines and triamine of different molecular weights and number of functionality, showed the tensile strength of 10.5 N/㎟ and 12.7 N/㎟, respectively and the elongation of 1165 % and 969%, respectively. Among the water dispersed urea resin synthesized with different contents of DMPA, PU-6 showed the highest mechanical properties, a tensile strength of 14.2 N/㎟ and an elongation of 993%. In addition, the water dispersion state of this PU-6 was the most stable even after 8 weeks.

• Journal of the Korea Institute of Building Construction
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• v.9 no.5
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• pp.145-153
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• 2009

The purpose of this research is to compare and analyze the change that must be applied to the evaluation of the slipperiness of an inclined floor, when considering its use by the physically handicapped and by the able-bodied. For this study, a simulator that can reproduce the characteristics of the body sway of a physically handicapped person was developed through a comparative experiment between able-bodied people and people with hemiplegia. In addition, as cale for the evaluation of the slipperiness of flat floors and inclined floors was composed by the sensory test result targeting physically handicapped persons (able-bodied persons wore the body sway for the handicapped and ageing in the experiment) and the able-bodied. In terms of the evaluation of the slipperiness of an inclined floor, it was evaluated that it is safe when the C.S.R' (Coefficient of Slip Resistance) of a healthy person is over 0.30, while it was evaluated that it is dangerous when the C.S.R' of a physically handicapped person is over $0.45{\sim}0.50$. Concerning this difference, it is judged that the reason for this difference is that the walking mechanism differs between an able-bodied person and a physically handicapped person.