No abstract

A new type of hollow slab making use of plastic air balls has been developed, which can effectively reduce the amount of concrete and self weight of concrete structures. In this study, flexural and free vibration tests were carried out to investigate flexural behaviour, including the flexural stiffness, cracking, strength, and ductility. Six test specimens were examined: two conventional RC slabs; two hollow slabs; and two partially precast concrete slabs. The test parameters also included two different types of plastic balls. The test results showed that the hollow slabs yield a satisfactory flexural behaviour (i.e., crack pattern, and flexural strength) which is similar to that of conventional concrete solid slabs up to the ultimate state. It was also found that the current design provisions for concrete solid slabs are applicable to hollow slabs, without significant modification, for the evaluation of flexural strength and initial stiffness essential to the serviceability check.

The purpose of this research is to examine the effect of storytelling ads. To find out the effect, three different ads were created; one is no storytelling in ads, another is corporate storytelling ads, and the other is client storytelling ads. Each ads was exposed to high school students, and we analyzed their response to the ads such as ads recall, attitude toward ads, emotional response to ads, purchase intention, and the intention of word-of-mouth. The results showed that corporate storytelling ads among three ads was the most effective to recall the ads, and there was significant difference between corporate storytelling ads and no storytelling ads. In terms of attitude toward ads, there was significant difference between client storytelling and no storytelling ads. There were significant difference in positive emotion between client storytelling ads and no storytelling ads and between client storytelling ads and corporate storytelling ads, but no significant between corporate storytelling ads and no storytelling ads. Regarding emotion, students who were exposed to no storytelling ads showed the highest negative emotion, but the lowest negative emotion in client storytelling ads. There was significant difference in purchase intention between client storytelling and no storytelling ads and in the intention of word-of-mouth between corporate storytelling ads and no storytelling ads.

A waffle-shaped precast concrete panel named WAS has been newly developed as a floor system. Compared to the conventional double tee (DT), the WAS has a more spacious connection area between the panels while having a shallower depth, which possibly results in an enhanced performance of the connection. Experimental studies were performed to examine the flexural behavior of the WAS according to several primary parameters: the panel types, prestress levels applied to the panels, panel sizes, and the existence of steel ties. Connection tests were also performed on the short and long edges of each panel against out-of-plane shear. The test results showed that the WAS panels yields satisfactory flexural capacity similar to the DT up to ultimate state, and they satisfy the deflection limit for serviceability while their stiffnesses were less than those of DT panels. It was also found that the ultimate flexural strength of the WAS panel increases as the applied prestress increases, and that the connections can undertake the applied bending moment and properly transfer the developed shear force between WAS panels. The enhanced performance of the WAS connection makes it possible to efficiently design the panels addressing the moment distribution, and to enhance the serviceability (less deflection and cracking) and structural continuity/integrity of the WAS system while still being able to reduce its depth.

Various form of membrane structures are being built in recent years. However, there is no appropriate fire proofing standards which can be applied each specific membrane structures. Therefore, existing fire protection standards are in establishment state and they need to be revised. In the current study, commonly used membrane materials(ETFE, PVF, PTFE) has been selected to investigate its fire resistance behavior with the change of fire duration time. In addition to this, heat generation rate of the membrane materials in correlation with the height of membrane has been investigated. And these fire combustion characteristics of membrane materials can be used in future practice for the fire prevention regulations of membrane structures.