• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.957-962
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• 2010

Foundation systems in urban sites are often necessary to be constructed with little vibrations and displacements to surroundings. In order to assess applicability of a new foundation system for urban sites based on soil-cement mixing technique, vibrations and displacements induced by soil-cement construction process is evaluated. Soil-cement columns were constructed to reinforce soft ground near an old masonry wall in an urban redevelopment site, and the vibrations and displacements of the old masonry wall during construction were measured. Results indicate that the vibrations and displacements induced by soil-cement construction were little and not critical to the stability of the masonry wall.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.119-120
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• 2015

Appropriate management of the finish works in construction project is one of most important activities that must be conducted considering the total duration of the project. Masonry work is a fundamental process that is performed in the preliminary steps of finish works. However, it has been investigated that the analysis of delay factors affecting masonry work has been neglected in the domestic construction site. Therefore, this study deducts delay factors affecting masonry work by literature review and survey on site engineers and labors. This study has been conducted as a preliminary step of developing a construction project interference management system which is expected to suggest objective information for the decision making in construction sites.

• Journal of Construction Engineering and Project Management
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• v.3 no.1
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• pp.28-34
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• 2013

Use of recycled aggregates in portland cement concrete (PCC) construction can offer benefits associated with both economy and sustainability. Testing performed to date indicates that recycled brick masonry aggregate (RBMA) can be used as a 100% replacement for conventional coarse aggregate in concrete that exhibits acceptable mechanical properties for use in structural and pavement elements, including satisfactory performance in some durability tests. Recycled brick masonry aggregate concrete (RBMAC) is currently not used in any type of construction in the United States. However, use of RBMAC could become a viable construction strategy as sustainable building practices become the norm. This paper explores the feasibility of use of RBMAC in several types of sustainable construction initiatives, based upon the findings of previous work with RBMAC that incorporates RBMA produced from construction and demolition waste from a case study site. A summary of material properties of RBMAC that will be useful to construction professionals are presented, along with a discussion of advantages and impediments to use. Several quality assurance and quality control techniques that could be incorporated into specifications are identified.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.234-235
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• 2019

In the stacking and pitching items of the stone masonry and demolition process presented by 2018's standard of estimate, 7 estimating standards are presented according to the depth of masonry stone, and it is presented that the quantity per unit increases as the depth of masonry stone grows. As a result of analyzing the application status in the site, it is shown that 2 or 3 stones are mainly used according to the stone sizes regardless of the depth of masonry stone, and that as the size of the stone becomes larger, the quantity per unit decreases due to the size per square meter(㎡). Also, in most of sites, machine construction is mainly carried out by excavators with clampers attached to them. Therefore, in the 2019's application standard of estimate, it is analyzed that the size is simplified down to 3 sizes reflecting the site application status and that it is revised as a standard reflecting the result that as the stone size becomes bigger, the productivity increases.

• Structural Engineering and Mechanics
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• v.67 no.6
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• pp.579-585
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• 2018

Masonry walls are of a complex (anisotropic) structure in terms of their mechanical properties. The mechanical properties of the walls are affected by the properties of the materials used in wall construction, joint thickness and the type of masonry bond. The carried-out studies, particularly in the seismic zones, have revealed that the most of the conventional masonry walls were constructed without considering any engineering approach. Along with that, large-scale damages were detected on such structural elements after major earthquake(s), and such damages were commonly occurred at the brick-joint interfaces. The aim of this study was to investigate the effect of joint thickness and also type of mortar on the mechanical behavior of the masonry walls. For this aim, the brick masonry walls were constructed through examination of both the literature and the conventional masonry walls. In the construction process, a single-type of brick was combined with two different types of mortar: cement mortar and hydraulic lime mortar. Three different joint thicknesses were used for each mortar type; thus, a total of six masonry walls were constructed in the laboratory. The mechanical properties of brick and mortars, and also of the constructed walls were determined. As a conclusion, it can be stated that the failure mechanism of the brick masonry walls differed due to the mechanical properties of the mortars. The use of bed joint thickness not less than 20 mm is recommended in construction of conventional masonry walls in order to maintain the act of brick in conjunction with mortar under load.

• Journal of the Korea Institute of Building Construction
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• v.13 no.4
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• pp.372-381
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• 2013

In the construction industry, a great deal of research has been focused on productivity improvement because a minor change in labor productivity can often make the difference between a profit and a loss. This study shows how productivity measurement methods can be applied in practice, step by step, to analyze and identify potential problems both in productivity and methods performance for masonry work. A work sampling technique was conducted to determine the nature and extent of an observable activity as an aid to measuring overall performance. Also, a method productivity delay model was used to identify non-productivity in individual cycle times. From the work sampling technique, it was found that the masonry crew had a Labor Utilization Factor of 47.1%, and from the videotape analysis, it was found that the material and dumpster location need to be adjusted to reduce the travelling distance. We have found that efforts to improve the productivity of masonry work should be focused almost exclusively on machine and labor delays, based on the result from the method productivity delay model.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.149-160
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• 2001

In this paper, the stability analyses were performed for masonry retaining wallls in Seoul subway System. This masonry retaining wallls were reinforced with earth anchor system for the construction, but it was removed after construction. Therefore, the stability of masonry retaining wallls should be checked after the earth anchors removed. For stability analysis of masonry retaining wallls. FDM analysis(FLAC Ver.3.3) and slope stability analysis (SLOPE/W) were performed applying the test results from laboratory and field tests(Schmidt hammer test, cack examination). As conclusion, the tension force of earth anchors should be kept, therefore, substitutional method was required in order to keep the tension force of earth anchor system.

• Earthquakes and Structures
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• v.22 no.5
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• pp.475-485
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• 2022

This paper presents a comparative experimental study on structural behavior of the interlocking masonry walls under in-plane cyclic loading. The main purpose of this study is to increase lateral load-bearing capacities of masonry walls by using interlocking units. The interlocking units were designed by considering failure modes of masonry walls and produced using lightweight foamed concrete. To this end, three masonry walls which are hollow, fully grouted, and reinforced were constructed with interlocking units. Also, a traditional masonry brick wall was built for comparison reasons. The walls were tested under in-plane cyclic loading. Then, structural parameters of the walls such as lateral load bearing and total energy dissipation capacities, ductility, stiffness degradation as well as failure modes obtained from the tests were compared with each other. The results have shown that the walls with the interlocking units have better structural performance than traditional masonry brick walls and they may be used in the construction of low-rise masonry structures in rural areas to improve in-plane structural performance.

• Coupled systems mechanics
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• v.4 no.2
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• pp.173-189
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• 2015

In reality, masonry infill modifies the seismic response of reinforced concrete (r.c.) frame structures by increasing the overall rigidity of structure which results in: increasing of total seismic load value, decreasing of deformations and period of vibration, therefore masonry infill frame structures have larger capacity of absorbing and dissipating seismic energy. The aim of the paper is to explore and assess actual influence of masonry infill on seismic response of r.c. frame structures, to determine whether it's justified to disregard masonry infill influence and to determine appropriate way to consider infill influence by design. This was done by modeling different structures, bare frame structures as well as masonry infill frame structures, while varying masonry infill to r.c. frame stiffness ratio and seismic intensity. Further resistance envelope for those models were created and compared. Different structures analysis have shown that the seismic action on infilled r.c. frame structure is almost always twice as much as seismic action on the same structure with bare r.c. frames, regardless of the seismic intensity. Comparing different models resistance envelopes has shown that, in case of lower stiffness r.c. frame structure, masonry infill (both lower and higher stiffness) increased its lateral load capacity, in average, two times, but in case of higher stiffness r.c. frame structures, influence of masonry infill on lateral load capacity is insignificant. After all, it is to conclude that the optimal structure type depends on its exposure to seismic action and its masonry infill to r.c. frame stiffness ratio.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1024-1031
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• 2022

In addressing the goal for sustainability in the construction industry, the very materials used for construction and the methods utilized to implement said materials must be analyzed. Specifically, some traditional residential construction materials consist of wood, steel, and concrete. Because these materials vary in their levels of sustainability, there is a need to develop and explore new or other materials that can be used for residential construction. The primary purpose of this paper is to provide a review of interlocking earthen masonry units (IEMU) as an alternative option for residential building construction. This is in an effort to explore the variables impacting their existing and potential applications as sustainable materials and a method for residential building construction. IEMU's are then examined under the triple bottom line (TBL) sustainability framework which includes analyzing the environmental, economic, and social sustainability of IEMU's. The findings of this review may lead to further progression in the development of a framework for evaluating U.S. stakeholder adoption of IEMU's and potential implementation in U.S. residential construction.