• Wind and Structures
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• v.22 no.2
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• pp.133-160
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• 2016

Hurricanes are among the most costly natural hazards to impact buildings in coastal regions. Building roofs are designed using the wind load provisions of building codes and standards and, in the case of large buildings, wind tunnel tests. Wind permeable roof claddings like roof pavers are not well dealt with in many existing building codes and standards. The objective of this paper is to develop simple guidance in code format for design of loose-laid roof pavers. Large-scale experiments were performed to investigate the wind loading on concrete roof pavers on the flat roof of a low-rise building in Wall of Wind, a large-scale hurricane testing facility at Florida International University. They included wind blow-off tests and pressure measurements on the top and bottom surfaces of pavers. Based on the experimental results simplified guidelines are developed for design of loose-laid roof pavers against wind uplift. The guidelines are formatted so that use can be made of the existing information in codes and standards such as American Society of Civil Engineering (ASCE) 7-10 standard's pressure coefficients for components and cladding. The effects of the pavers' edge-gap to spacer height ratio and parapet height to building height ratio are included in the guidelines as adjustment factors.

• The Korean Journal of Ceramics
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• v.4 no.4
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• pp.368-371
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• 1998

The work aims to evaluate the necessary physical properties of Abrasion Resistant Pavers designed for high volume pedestrian and road vehicle traffic and their influence on the selection of raw materials and ceramic processes. The pavers' specifications such as high strength and ware resistance demand a careful clay preparation, slow drying, slow firing and a balanced chemical and mineralogical composition. Therefore, developing abrasion Resistant Pavers in existing modern brickmaking plants, which are designed primarily for making bricks and pavers for domestic applications, has become a challenge for manufacturers and ceramic professionals. The significance of quality control and research and development in the production of these high class pavers is also emphasised in this work through the investigation of a paver that exhibits shrinkage cracking.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.47-54
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• 1994

Full-scale and 1:15 scale fluid model experiments of roof ballast pavers are employed to optimize paver geometry and study wind loading and performance of roof ballast pavers. Wind pressures above and beneath pavers are conducted for buildings of different heights and in different flow conditions. The effects of the side hole size and the underneath rib height under the wind loading on pavers and the effects of roof parapet height as well as flow conditions on the performance of pavers are studied. Incorporation of wind tunnel experimental results into code statements is also provided.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.11-18
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• 2014

PURPOSES : This study aims to develop a strength test method for irregularly shaped concrete block paver. METHODS : Ten (10) different types of concrete block pavers including porous and dense blocks were tested for strength capacities. Destructive and non-destructive methods were used to develop a strength test method for irregularly shaped concrete block paver. The flexural strength evaluation was conducted in accordance to KS F 4419, while compressive strength was conducted with a 45.7mm-diameter core specimen. The impact echo test method was used to evaluate the elastic modulus. Finally, regression analysis was used to investigate the relationship between flexural strength, compressive strength and elastic modulus based on their corresponding test results. RESULTS : The flexural strength of the tested block pavers ranged from 4MPa to 10MPa. At 95% confidence level, the coefficients of determination between compressive-flexural strength relationship and compressive strength-elastic modulus relationship were 0.94 and 0.84, respectively. These coefficients signified high correlation. CONCLUSIONS : Using the test method proposed in this study, it will be easier to evaluate the strength of irregularly shaped concrete block pavers through impact echo test and compressive test, instead of the flexural test. Relative to the flexural strength requirement of 5MPa, the minimum values of compressive strength and elastic modulus, as proposed, are 13.0MPa and 25.0GPa, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.35-36
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• 2018

Korea has many problems due to the asphalt pavement or impermeable pavement. Many methods are being implemented to improve water circulation. Among them, permeable packaging materials are used. However, existing permeable packaging materials have a problem of causing efflorescence and clogging the pores. The pores of the permeable packing material are clogged and the permeability is lost. This leads to economic problems and product problems. The purpose of this study was to develop a block to prevent efflorescence.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.263-264
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• 2005

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.454-461
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• 2015

This study aims to classify the biotope types based on the vegetation community in built-up areas by different land use and to map the plant communities. By classifying biotopes according to a taxonomic system, the characteristics of a biological community can be well-represented. The biotope classification indexes for the target area include human behavioral factors such as land use intensity, land-use patterns and land-cover types. The type classification was divided into four hierarchic ranks starting with Biotope Class, next by Biotope Group and Biotope Type and lastly by Biotope Sub-Type. The Biotope Class was first divided into two areas: the areas improved by humans and the areas unimproved by humans. The improved areas were again divided into permeable and non-permeable regions on the Biotope Group level. In the Biotope Type level, permeable paving areas were divided into areas with wide gap pavers and those with narrow gap pavers. The differential species of each biotope type are Lindera glauca, Conyza canadensis, Mazus pumilus, Vicia tetrasperma, Crepidiastrum sonchifolium, Zoysis japonica, Potentilla supina and Festuca arundinacea. The results of this study suggest that the biotope classification methodology, using a subjective phytosociological approach, is a useful and valuable tool and the results also suggest the possibility of applying more objective and scientific methods in mapping and classifying various environments.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.100-109
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• 2012

Large road construction projects are typically partitioned into sections that are then contracted individually to contractors. Each section requires using similar heavy equipment including excavators, dump trucks and pavers, which constitute the highest cost. Normally the equipment is not shared between them, as each contractor wishes to have their equipment readily available. However, such practices result in very low utilization of these equipment. The goal of this research is to develop a programmatic resource sharing system in which contractors can share equipment depending on the changing needs of a multi-sectioned road project. This paper introduces the results of a survey performed to investigate how contractors currently manage the supply and demand of equipment and the equipment that are practical for sharing across a project. More importantly, the paper describes a set of metrics (DPR, nDPR, SDI) needed to quantify the amount of supply/demand variance occurring in each section. The metrics were used on an actual road construction project, and the results show that each section suffers from an imbalance between its monthly planned and actual utilization of equipment. The results also indicate that the sharing of the equipment can lead to potentially large savings as equipment requirements can be met within a project as to short leasing from outside vendors.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.111-121
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• 2010

As the customer's interest for sidewalk block in the street or apartment complex is increasing, the materials of block which had been a concrete block exclusively are varied to clay paver, native rock and wood etc. Especially, the sales volume of clay paver which is environment-friendly and ergonomic is dramatically increasing every year with two digits growth rate, however, many problems like "Edge Cracking" "Freezing Breakage" "Bending Breakage" "Joint Gap" are happening frequently within a couple of hours after installation due to the durabilities. Because of the characteristics of Ceramic products, clay pavers are very easy to be broken when they are bumped against each other. In addition, they are relatively fragile by a freezing expansion breakage when exposed to water due to hydrophilic property as well as the intensity and absorptance of the products are varied with small difference from the production process such as production equipment and process control. Therefore, it costs a lot of money to repair the breakdown unless production and installation is carried out according to the strict criteria of the quality control. In this study, the symptoms of breakdown frequently happened in clay paver are classified by each type and finally the solution for this problem in the production of brick, installation and criteria of quality control through compressive strength and absorptance test is suggested.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.318-345
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• 2013

This study was carried out with a focus on the factor on the periodical space organization of Daebodan (大報壇: the altar of great recompense) in Changdeok Palace, which is significant in terms of political history in the late Chosun Dynasty, and consider the factors in the formation of the structural system through historical records and drawings. Daebodan has the ideology of righteousness to the Ming Dynasty which the hierarchy of the Joseon Dynasty. who felt the crisis of the domination order, imposed as a solution after the Manchu war of 1636. In addition, Daebodan was built by complex factors that entailed the self-esteem of the 'Joseon Centralism Ideology (朝鮮中華)' and the desire of the sacrificial rituals for Heaven that were imminent to the kings of Joseon. Superficially, Daebodan has the spatial organization of the Sajik (社稷) Altar and the placement of an annex building, but had the applied placement due to limited topography and access to the backyard. Furthermore, the lateral structure of Daebodan multiply accepted various factors of the nine step's stairs, the hight of five cheok (尺), the circumstance of two floors that were showed in the altar and platform with small fences and an imperial order including the internal form of Hwangjangbang (黃帳房). Moreover, the name of the alter came from 'the Jiaote Sheng Book of Rites(禮記 郊特牲)' representing 'the suburban sacrifice ritual for Heaven (郊天)', and it was built by not only combining the system of the Sajik Altar in the Joseon Dynasty and China but also avoiding 'excessive etiquette (僭禮).' The point is a remarkable feature shown by the structural system of Daebodan. Thus, it is considered that the 'Notion of Confucian-Cultural Succession (中華繼承意識)' and the desire of the sacrificial rituals for Heaven were expressed by the structure and form of altar. This study examined the process of the creation, expansion, decline and disposal of Daebodan in a chronological order, and found that the ruling ideology of the governing elite by the political and cultural background of the era at each transitional point was reflected in the spatial formation of the altar. On the other hand, as a result of performing a field survey to find the location in accordance with Daebodan in drawing materials, there remains items such as worked stones from Daebodan, precast pavers and fragments of proof tile discovered in the surrounding of tora vine (Actinidia arguta) which is a natural monument of Changdeok Palace. As such, verification through future excavation and investigation is required.