• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.175-176
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• 2023

The masonry structure is constructed by cement mortar binding material of brick objects and uses reinforced hardware(connected hardware or wall tie) together when building. However, over time, the corrosion of reinforced steel and the deterioration of joint mortar as well as bricks cause the risk of collapse. In particular, when the externally decorated brick wall is installed on the concrete girder for each floor, the angle bracket is not constructed or corroded, the full-layer weight load is applied to the wall of 0.5B, which is an example of full-scale or collapse. As a result of the evaluation, it was confirmed that the performance was improved compared to the existing bracket, and we plan to carry out a real-life test and long-term performance review of the building using the bracket in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.105-106
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• 2021

This study examines the performance of CBS-Dust for the utilization of cement bricks as alkali stimulants for furnace slag replacement binders. It converts the CBS-Dust substitution rate and the excess slag substitution rate. According to the analysis, when replacing CBS-Dust with 65~70 % of BS substitution rate and 7.5~10 % of CBS-Dust, it shows excellent performance as an alkali stimulant of BS' potential hydrophobic reaction, and it is expected to be effective for secondary products of BS replaced in large quantities.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.55-62
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• 2010

This is an experimental research in order to judge the applicability of sewage sludge incineration ash having applied the mixing proportion needed to manufacture bricks and to do plaster work with addition of hwangtoh and slaked lime as a part of the methods for utilizing the wastes produced from sewage sludge incineration ash. Based on the results from experiment and analysis, it is judged that, in case of mixing proportion of 1:2 for the purpose of plastering and masonry work, the cement mortar produced by using a 10% addition ratio of sewage sludge incineration ash with mixture of hwangtoh covering all range of addition ratio, and also the cement mortar produced by using a 20% of sewage sludge incineration ash together with 0% and 10% addition ratio of hwangtoh, was possible to be applied to the practical use. In case of mixing proportion of 1:7 for manufacture of bricks and blocks, if such brick and block products are produced with 10% and 20% addition ratio of sewage sludge incineration ash having added aggregate fines or stone dust that has been actually used in brick and block manufacturing, it is judged that these bricks and blocks could be practically used in the job sites, although strength development is a little bit lower.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.453-458
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• 2001

This study was performed to reuse the dyeing wastewater sludge treated by Fenton process through the solidification/stabilization technique. To solidify the dyeing sludge the industrial by-products such as blast furnace slag, fly ash and waste sand with cement were used. The laboratory scale and pilot scale test were conducted at room temperature to make construction brick which has high compressive strength and low leaching of heavy metals. The experimental results showed that blast furnace slag and fly ash could be used instead of cement and the products satisfied the regulation of Korean Standards. The blast furnace slag increased the compressive strength and the optimum ratio of slag/dyeing sludge on dry basis was found 0.4. The solidifying agent of SB series could increase rapidly the compressive strength and the optimum ratio of solidifying agent/sludge on dry basis was 0.26 at which the strength was two times compared with non-added condition. The portion of waste and industrial by-products in matrix was over 80%. From the pilot test the optimum pressure in molding was 100kg/$\textrm{cm}^2$ at which the compressive strength was over 100kg/$\textrm{cm}^2$. And the strength increased continuously to 160kg/$\textrm{cm}^2$ until 120 days curing time due to pozzolanic reaction. When SB-20 as a solidifying agent was used, the unconfined compressive strength of dyeing sludge could be obtained 110kg/$\textrm{cm}^2$ which satisfied the regulation of cement brick in Korea Standard(KS).

• Earthquakes and Structures
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• v.5 no.4
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• pp.477-497
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• 2013

This paper reports extensive experimental study done to compare workability and bond strength of five different types of polymer-based bonding agents for reinforcing bars in pinning retrofit. In pinning retrofit, steel pins of 6 to 10 mm diameters are inserted into holes drilled diagonally from mortar joints. This technique is superior to other techniques especially in retrofitting historic masonry constructions because it does not change the appearance of constructions. With an ordinary cement paste as bonding agent, it is very difficult to insert reinforcing bars at larger open times due to poor workability and very thin clearance available. Here, open time represents the time interval between the injection of bonding agent and the insertion of reinforcing bars. Use of polymer-cement paste (PCP), as bonding agent, is proposed in this study, with investigation on workability and bond strengths of various PCPs in brick masonry, at open times up to 10 minutes, which is unavoidable in practice. Corresponding nonlinear finite element models are developed to simulate the experimental observations. From the experimental and analytical study, the Styrene-Butadiene Rubber polymer-cement paste (SBR-PCP) with prior pretreatments of drilled holes showed strong bond with minimum strength variation at larger open times.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.87-98
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• 2011

Clay bricks with lime mortar are recently popular since they are eco- and environment-friendly construction material being capable of air flow and moisture movement. However, there is little study on those of clay brick an lime mortar while relatively many researches on the structural characteristics of concrete bricks with cement mortar are available in Korea. Furthermore, the current Korean Building Code of masonry structures was established on the base of the Foreign Codes which does not reflect Korean masonry construction circumstance, such as material characteristics and section properties. To overcome these problems, experiments of masonry structures constructed using clay bricks with lime mortar were carried out to evaluate their structural characteristics such as, prism compressive strength, adhesive strength and diagonal tensile(shear) strength. Also this research compares the mechanical characteristics between clay bricks with lime mortar and concrete bricks with cement mortar to provide information that will be used for revisions of the domestic standards for masonry structures. As masonry structures constructed with clay bricks and lime mortar show different aspects over the ones constructed with concrete bricks and cement mortar, we suggest estimation equation of prism compressive strength and diagonal tensile strength on masonry structures constructed with clay bricks and lime mortar.

• Advances in concrete construction
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• v.2 no.4
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• pp.249-259
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• 2014

Mortar is a masonry product which is matrix of concrete. It consists of binder and fine aggregate and moreover, it is an essential associate in any reinforced structural construction. The strength of mortar is a special concern to the engineer because mortar is responsible to give protection in the outer part of the structure as well as at a brick joint in masonry wall system. The purpose of this research is to investigate the compressive strength and tensile strength of mortar, which are important mechanical properties, by replacing the cement and sand by stone dust. Moreover, to minimize the increasing demand of cement and sand, checking of appropriateness of stone dust as a construction material is necessary to ensure both solid waste minimization and recovery by exchanging stone dust with cement and sand. Stone dust passing by No. 200 sieve, is used as cement replacing material and retained by No. 100 sieve is used for sand replacement. Sand was replaced by stone dust of 15%, 20%, 25%, 30%, 35%, 40%, 45% and 50% by weight of sand while cement was replaced by stone dust of 3%, 5%, and 7% by weight of cement. Test result indicates that, compressive strength of specimen mix with 35% of sand replacing stone dust and 3% of cement replacing stone dust increases 21.33% and 22.76% respectively than the normal mortar specimen at 7 and 28 days while for tensile it increases up to 13.47%. At the end, optimum dose was selected and crack analysis as well as discussion also included.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.457-460
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• 2006

There are many kind of materials decorating outward of building such as paint, tile, brick, wood, stone and so on. But it has been pointed out some problems because of the industrial pollutions and wastes. Color concrete is a method of expressing out surface of exposed concrete. Generally, color concrete is manufactured by adding pigment to concrete. In this paper we used cement paste as a preparation step to apply to concrete. Pigment was added to white cement for easy observance of color difference. And color change was measured by color reader. Finally, we can predict color difference according to amount of pigment. Also, we investigate the color concrete technology for Art type using developed color concrete.

• KIEAE Journal
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• v.3 no.2
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• pp.37-44
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• 2003

The aim of this study was to analyze the thermal performance through Test-Cell of TI-wall in domestic climate. This study was carried out as follows: 1) The TI-wall was studied for ability to reduce heat loss through the building envelope and analyzed to TIM properties. 2) Test models of TI-wall were designed through the investigation of previous paper and work, measured for winter and spring, and the thermal effects were analyzed. The type of the TIM used in test model is small-celled(diameter 4mm and thickness 50mm) capillary and cement brick(density $1500kg/m^3$) was used by thermal mass. 3) Test-cell of TI-wall was calibrated from measured data and the dynamic simulation program ESP-r 9.0. In these simulations, the measured climate conditions of TaeJon were used as outdoor conditions, and the simulation model of Test-cell was developed. 4) The sensitivity analysis is executed in various aspects with standard weather files and ESP-r 9.0, and then most suitable system of TI-wall are predicted. Finally, The suitable system of TI-wall was analysed according to sizes of air gap, kinds, thickness, and the surface absorption of therm wall. The result is following. In TI-wall, Concrete is better than cement brick, at that time the surface absorption is 95%, and the most efficient thickness is 250mm. As smaller of a air gap, as reducer of convection heat loss, it is efficient for heating energy. However, ensuring of a air gap at least more than 50mm is desirable for natural ventilation in Summer.

• Journal of the Mineralogical Society of Korea
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• v.31 no.3
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• pp.149-159
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• 2018

The Gyeongju Bunhwangsa Stone Brick Pagoda, which was built with bricks of andesite, is the oldest brick stone pagoda of Silla period. The damage patterns in the stone pagoda are pollutants such as white crust, black crust, discoloration, soil adsorption, and microorganisms, and repair materials. The damage pattern of structural factors in the Stone Brick Pagoda is a bulging phenomenon. According to the X-ray diffraction analysis, white crust are mainly consist of calcite ($CaCO_3$) and thermonatrite ($Na_2CO_3{\cdot}H_2O$) that evaporite finds in nature. Damage pattern varies depending on location of stone pagoda. The pollutants are first story body of pagoda. The microorganisms are confirmed at base, lion statues, first and second story capstone, and repair materials observed at base. The bulging phenomenon appeared on the first story body of the pagoda. Occupancy rates by damage type were higher in the order of microorganisms, pollutants, repair material, bulging phenomenon, and peeling. The highest percentage of individual damage patterns were black microorganisms (39.3%), followed by lichen (17.9%), discoloration (8.0%), white crust (5.5%), cement mortar (5.1%) and peeling (3.1%).