• Fire Science and Engineering
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• v.29 no.4
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• pp.49-56
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• 2015

Toxic gases from five types of interior building materials were investigated according to Naval Engineering Standard (NES) 713. The materials were plywood, indoor wall coverings (wood wall plate members and pine wood), reinforced Styrofoam insulation, laminate flooring, and PVC. Specimens were measured using an NES 713 toxicity test apparatus to analyze the hazardous substances in combustion gas from the materials. We used the US Department of Defense standard (MIL-DTL, Military Standard) to calculate the toxicity index of the combustion gas. Emissions of $CO_2$ from all specimens did not exceed the NES 713 limit of 100,000 ppm. The amount of CO gas emissions from reinforced Styrofoam insulation was 6,098 ppm. 25 ppm and 49 ppm of formaldehyde were released from the reinforced Styrofoam insulation and PVC flooring, respectively. These values were less than the limit of 400 ppm. The highest emissions were from $NO_X$ emitted by plywood and were above the limit of 250 ppm. The toxicity index of the specimens were calculated as 5.19 for plywood, 4.13 for PVC flooring, 2.35 for reinforced Styrofoam insulation, 2.34 for laminate flooring, and 1.22 for indoor wall coverings (pine wood). Our research helps us to understand the properties of these five interior materials by analyzing the combustion gas and explaining the toxicity of constituents and the toxicity index. Also, it would be useful for giving fundamentals to guide the safe use of interior materials for applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.725-730
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• 2017

The strength ratio of the main structures of buildings gradually increasing, due to the advances made in analysis and cost saving techniques. In this study, to examine the stability of industry buildings using sandwich panels as roof assemblies, we examine the changes in the moment strength ratio of the main structures caused by increasing the roof load. This study adopts the PEB structure and three H-steel structure as the structural analysis models. In the case where the additional load exceeds about 11% of the roof design load, the strength ratio exceeds 1 for the main structure. In the case where the additional load exceeds about 36%(of the roof design load), the working moment exceeds the plastic moments, which leads to major damage to the structure. This study compares 1) the maximum load according to the purlin spaces, 2) the maximum load by KS, and 3) the maximum load calculated from the test results of the manufacturer.The maximum bearing load of the panels determined by all three methods exceeds the structure failure threshold load of the main structure. This study provides evidence that an unexpected increase in the roof load might cause the whole structure to collapse, due to the failure of the main structural members, before the failure of the roof assemblies. Therefore, information on the structural performance of the sandwich panels is required for the structural design, and the sandwich panels should be considered to be an integral part of the overall structural design.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.1
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• pp.1-12
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• 2012

In this paper, the reduction factors to calculate the site coefficients of an embedded foundation are estimated, considering the effect of a poor backfill for the seismic design of a building built on an embedded foundation. This is determined by utilizing in-house finite element software, P3DASS, which has the capability of horizontal pseudo 3D seismic analysis with nonlinear soil. The 30m thick soil on stiff rock was assumed to be homogeneous, elastic, viscous and isotropic, and equivalent circular rigid foundations with radii of 10-70m were assumed to be embedded 0, 10, 20, and 30 m in the soil. Seismic analyses were performed with 7 bedrock earthquake records de-convoluted from the outcrop records; the scaling of the peak ground accelerations were to 0.1 g. The study results show that the site coefficients of a poor-backfilled foundation are gradually reduced as the foundation embedment ratio increases, except in the case of a small foundation embedded deeply in the weak soft soil. In addition, it was found that the deviation of the site coefficients due to the foundation size was not significant. Therefore, the typical reduction factors of an embedded foundation with poor backfill are proposed in terms of the shear wave velocity and site class. This is in order to find the site coefficients of an embedded foundation by multiplying the reduction factor by a site coefficient of a surface foundation specified in the design code. They can then be interpolated to determine the intermediate shear wave velocity.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.307-316
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• 2015

Although the use of CAD and CAM technologies has been broadly adopted by architecture-engineering- construction-facility management (AEC/FM) industry as the means of producing complex forms, there are still remained issues such as reducing cost, and enhancing quality and manufacturability. In this paper, to resolve given issues, we suggest a process of rationalization in digital architecture design and fabrication as an integrated approach. The rationalization, which is usually used as the term related with the skin panel of free-form architecture, is a process of re-designing a digital model to meet the requirements of manufacturing considering the gap with an original designs. Thus we classified this process and conducted a case study of fabricated models as an exploratory study. As the result, we found that each phase is connected with other phases with the circulation of information and rationalization process can be determined as the circulative process which re-designs digital model by minimally deviating from the original design based on the information deducted from analysis of inter-compatability of software and requirement of hardware.

• Journal of the Korea Institute of Building Construction
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• v.11 no.2
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• pp.127-135
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• 2011

In this study, the engineering characteristics of outer wall insulation panels according to type of insulation materials, their combination, and the contents of insulation materials were tested. Vermiculate, ceramic bead, perlite and expanded polystyrene were used as insulation materials. Flexural strength and thermal conductivity depending on the insulation materials used were measured. It was found that the flow of fresh mortar significantly decreased with an increase in the contents of insulation materials. In terms of the effect of insulation materials on thermal conductivity, an increase in insulation materials resulted in a decrease of thermal conductivity. In particular, PL and EPS, when used together, have lower thermal conductivity than other materials. Regarding the flexural strength of the hardened mortar, the strength showed a tendency to gradually decrease according to the increase in contents of insulation materials, compared to that of the plain mortar. In terms of the flexural strength depending on various types of insulation materials and its combination, it was found that the flexural strength of cement mortar containing 3% of vermiculate(V)+ceramic bead(CB)+perlite(PL) was the highest among the specimens tested.

• Korean Journal of Construction Engineering and Management
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• v.11 no.2
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• pp.64-73
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• 2010

The stagnation of unsold houses is recently aggravated due to domestic and overseas crisis of finance and real-sector economy and domestic housing construction is in serious difficulty. Thus, tax support is necessary for national housing construction. Due to the current tax exemption system of national housing, V.A.T. paid in the construction of national housing is not deducted. Namely, it is ascribed to consumer as it is reflected in the construction cost. This research intends to analyze the limit of V.A.T. tax exemption system, to present the necessity of applying zero rate and to calculate the scale of non-deduction of V.A.T. purchase tax amount for national housing by analyzing the construction site of apartment house of house constructor in order to analyze the effect of zero rate when it is applied on the basis of above ground. In the zero rate system, V.A.T. is not collected from the consumers like the present tax exemption system. However, the purchase tax amount borne in the construction of national housing is deducted totally. As purchase tax is deducted, constructor will promote supplying national housing thanks to the effect of solving financial difficulties and improving liquidity. Since the architecture cost and parceling-out price can be lowered due to the improved liquidity of constructor, the policy will actually help the people without house.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.615-621
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• 2014

This study suggests the design and assembly drawing of the prefabricated precast concrete arch ammo magazines using the numerical analysis as well as the explosion verification test. The protective capacity of the proposed magazines is identified with the maximum support rotation angles measured by explosion verification tests according to the U.S. Unified Facility Criteria 3-340-02. Using numerical analysis, it is examined that oval-type members are better than the semi-circle ones in terms of protective capacity. Based on this numerical results, the design and assemble drawing for the prefabricated precast concrete arch ammo magazine are developed. It is identified that the structure constructed by invented design and assembly drawing has enough protective capacity against blast pressure caused by 133.75kg TNT explosion. The detonation point cannot be open due to the military security. In sum, it could be concluded that the ammo magazine proposed in this study has reliable protective capacity with enough redundancy. The redundancy means that there are more economic design approach with reducing the curved wall thickness.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.14-21
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• 2011

A unit modular system is a construction method which installs on site by manufacturing 50%~90% of the whole process in the factory. This method can minimize the process in the site and maximize the operation, which will reduce the duration and improve the overall quality. The recent paradigm of construction is to be sustainable building. Modular system can be regarded as a sustainable building construction method because it can reduce the amount of construction waste by recycling partial or whole part of overdue building be torn down. A unit modular system is the answer to cope with the increasing market of small size housings. A unit modular system is the most appropriate option at this point. This research proposes the standard operation and construction process of modular system, which enable to optimal system. A case study of reconstructing small-size housing was introduced to support this proposal. Finished unit modular is the reasonable way. However, 80% of complication rate of the modular is the most rational when a defect occurrence during delivery is considered.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.4
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• pp.1-15
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• 2010

In this study, the reduction factor of the code-defined site coefficient due to the embedment of a foundation was estimated for the seismic analysis of a building built on a soft soil site. This was done by utilizing the in-house finite element software P3DASS, which has the capability of pseudo 3D seismic analysis with nonlinear soil layers. A 30m thick soft soil site laid on the rock was assumed to be homogeneous, elastic, viscous and isotropic, and equivalent circular rigid foundations with radii of 10-70m were considered to be embedded at 0, 10, 20 and 30m in the soil layer. Seismic analyses were performed with 7 bedrock earthquake records deconvoluted from the outcrop records of which the effective ground acceleration was scaled to 0.1g. The study results showed that the site coefficients are gradually reduced except in the case of a small foundation embedded deeply in the weak soil layer, and it was estimated that the deviation of the site coefficients due to the foundation size was not significant. The standard reduction factor due to the foundation embedment were calculated adding the standard deviation to the average of 5 reduction factors calculated for 5 different foundation radii. Standard reduction factors for the site amplification factor were proposed for the practical amplification and the codes of KBC, etc., in accordance with the average shear wave velocity of the site, and the site class.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.957-967
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• 2013

While a vast number of cad drawings are produced in the life cycle of construction projects from the planning, design, and construction phases to the maintenance and control phases, the creation and distribution of non-standard drawings make it difficult for the construction parties to communicate with one another and to recycle, maintain, and control drawings by project phase. The Korea standard of CAD drawing in construction CALS/EC, which stipulates the standard for construction CAD drawings, is based on roads, rivers, and railways in line- and unit-based structures, allowing the creation of standardized CAD drawings. Such standard, however, cannot be easily applied to construction projects with multiple facilities like harbors, housing sites, or lands consisting of surface forms. In particular, port field consist of complex docks and amenities located in a certain coastal area based on multiple objectives. They also contain the concept of housing sites, like background land, and are composed of various civil engineering facilities, construction facilities, and port field, so that the existing CAD drawing standard cannot be easily implemented. Therefore, the purpose of this study is to maximize the efficiency of the information related to drawing information and to ultimately support smooth information exchanges in construction design by conducting a development research on the expansion of the CAD drawing standard that meets the needs of port field.