• Geomechanics and Engineering
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• v.1 no.3
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• pp.193-204
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• 2009

A 10.4-m high highway embankment retained behind mechanically stabilized earth (MSE) walls is under construction in the northeastern part of the Indian state of Bihar. The structure is constructed with compacted, micaceous, grey, silty sand, reinforced with polyester (PET) geogrids, and faced with reinforced cement concrete fascia panels. The connections between the fascia panels and the geogrids failed on several occasions during the monsoon seasons of 2007 and 2008 following episodes of heavy rainfall, when the embankment was still under construction. However, during these incidents the MSE embankment itself remained by and large stable and the collateral damages were minimal. The observational data during these incidents presented an opportunity to develop and calibrate a simple procedure for estimating rainfall induced pore water pressure development within MSE embankments constructed with backfill materials that do not allow unimpeded seepage. A simple analytical finite element model was developed for the purpose. The modeling results were found to agree with the observational and meteorological records from the site. These results also indicated that the threshold rainwater infiltration flux needed for the development of pore water pressure within an MSE embankment is a monotonically increasing function of the hydraulic conductivity of backfill. Specifically for the MSE embankment upon which this study is based, the analytical results indicated that the instabilities could have been avoided by having in place a chimney drain immediately behind the fascia panels.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.75-77
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• 2014

Using sealant for window installation is sealing the gap between the window frame and outer wall (such as concrete). A sealant serves to prevent external environmental impacts such as moisture, rain, sand, and dust entering inside of the building and make the building durable. In order to fulfill basic jointing function of sealing, at least 6 mm joint gap between two bonding surfaces are required. Also, adhesion performance between sealant and surfaces and the compatibility with other building materials are required to check before installation. In general, 2 part polyurethane sealant and 1 part silicone sealant are most common materials for sealing the joint of window. In this study, adhesion performances of those two generic sealants reflecting actual application conditions and the compatibility evaluations with other building materials are conducted to propose proper window installation procedures.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.39-46
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• 2015

REMICON(Ready Mixed Concrete), the most essential material of construction work, is produced from facility called "Batcher plant." In order to produce Remicon, Batcher Plant needs to be supplied with basic raw material such as ballast, sand, cement, admixture and water. In remicon industry, overland transport vehicles are used during the whole manufacturing process from producing to infilling at the construction site. Thus, the transportation cost sums up be to 20 percent of whole manufacturing cost and transport capacity and distance travelled have direct and major effect on manufacturing costs. This paper suggests a method to find optimal location of batcher plant using modified Steiner point, suggesting the most effective and flexible connection through among construction site, aggregate, cement and remicon producing plant. This paper also proposes reducing of transport cost at maximum 60% by calculation through optimized plant location. The modified Steiner point theory proposed in this paper also can be applied to optimal location of a $2^{ry}$ substation or MCC panel for minimizing of power loss, voltage drop, line distance and etc.

• Advances in concrete construction
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• v.10 no.6
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• pp.537-546
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• 2020

Exterior walls in buildings are exposed to various forms of thermal loads, which depend on the positions of walls. Therefore, one of the efficient methods for improving the energy competence of buildings is improving the thermal properties of insulation plaster mortar. In this study, lightweight fine aggregate (LWFA) and micro rubber ash (MRA) from recycled tires were used as partial replacements for sand. The flow ability, unit weight, compressive strength, tensile strength, thermal conductivity (K-value), drying shrinkage and microstructure scan of lightweight rubberized mortar (LWRM) were investigated. Ten mixtures of LWRM were prepared as follows: traditional cement mortar (control mixture); three mixes with different percentages of LWFA (25%, 50% and 75%); three mixes with different percentages of MRA (2.5%, 5% and 7.5%); and three mixes consisting both types with determined ratios (25% LWFA+5% MRA, 50% LWFA+5% MRA and 75% LWFA+5% MRA). The flow ability of the mortars was 22±2 cm, and LWRM contained LWFA and MRA. The compressive and tensile strength decreased by approximately 64% and 57%, respectively, when 75% LWFA was used compared with those when the control mix was used. The compressive and tensile strength decreased when 5% MRA was used. By contrast, mixes with determined ratios of LWFA and MRA affected reduced unit weight, K-value and dry shrinkage.

• Advances in materials Research
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• v.12 no.4
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• pp.287-308
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• 2023

The main objective of this article is to highlight the progress made in the development of new materials that have been gradually used by humans until today. Of course, this progress must be associated with other parameters in order to guarantee sustainable development. For this, today, it has become urgent to reduce the consumption of cement by resorting to its partial or total replacement by other similar materials in order to reduce CO₂ emissions in our environment. This should certainly help to develop greener building materials. In this study, it was decided to proceed with the partial or total replacement of Portland cement type CEM II/B-L-42.5N by slate and lime that had not undergone any previous transformation. The results obtained revealed that the mortar whose substitution compared to the replacement of cement (100%) cement and sand (0/4) confers better kinetics than those of the series composed of(100%) cement and fraction rubble (0/1).

• Advances in materials Research
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• v.13 no.5
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• pp.375-389
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• 2024

Installing wiring or plumbing fixtures necessitates creating chases within masonry walls, which, while serving practical purposes, raises a crucial concern regarding the potential compromise of the masonry's structural integrity. Given these concerns, it becomes essential to thoroughly understand the impact of incorporating chases on masonry strength. In this study, 37 AAC masonry prisms (200×330×100 mm³) were cast and tested for compression. The prisms were equipped with chases of various depths -10 mm, 20 mm and 30 mm; and orientations (horizontal, inclined, and vertical), which were then filled with mortar using 1:2, 1:4, and 1:6 cement-to-sand ratios. The primary objectives were to assess the strength decrease in the prisms with different chase characteristics compared to a control specimen and to determine the percentage strength increase due to filling materials compared to unfilled chases. Key findings indicate that as chase depth increases, there is a substantial reduction in prism strength. However, the orientation of the chase does not significantly affect strength reduction. Importantly, filling the chases with mortar leads to a significant increase in prism strength. This study not only unveils the complex impact of chase characteristics on masonry strength but also emphasizes the crucial role of filling materials in strengthening these prisms.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.380-385
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• 2014

Spherical atomizing reduction steel slag was prepared by atomizing technology using reduction steel slag (ladle furnace slag, LFS) generated from steel industry. In order to develop the mass-recycling technology of atomizing reduction steel slag, polymer concrete composite was prepared using spherical atomizing reduction steel slag instead of fine aggregate (river sand) and coarse aggregate (crushed aggregate), depending on the grain size. Different polymer concrete specimens were prepared with the various proportions of polymer binder and replacement ratios of atomizing reduction steel slag in order to investigate the characteristics of polymer concrete composite. Results showed that compressive strengths of polymer concrete specimens decreased with the increase of replacement ratios of atomizing reduction steel slag, but flexural strengths of the specimens showed a maximum strength at the 50% of replacement ratios of atomizing reduction steel slag. It was concluded that addition ratio of polymer binder, which affect greatly on the prime cost of production of polymer concrete, could be reduced by maximum 18.2 vol% because the workability of the polymer concrete was remarkably improved by using the atomizing reduction steel slag. However, further study is required because the mechanical strength of the specimen using atomizing reduction steel slag was greatly reduced in hot water resistance test.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.364-371
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• 2015

For the cost down of polymer concrete, It is very important to reduce the use amount of polymer binder, which occupies most of the production cost of polymer concrete. Fly ash and atomizing reduction steel slag are spherical materials obtained from industrial by-products. Spherical atomizing reduction steel slag was manufactured using steel slag from reduction process of ladle furnace by atomizing technology. To investigate the physical properties of polymer concrete, polymer concrete specimens were prepared with the various proportions of polymer binder and replacement ratios of atomizing steel slag. Results showed that compressive and flexural strengths of the specimens were remarkably increased with the addition amount of polymer binder and the replacement ratios of atomizing steel slag. In the hot water resistance test, compressive strength, flexural strength, bulk density and average pore diameter decreased but total pore volume and pore diameter increased. We found that polymer concrete developed in this study reduced the amount of polymer binder by 18.2% compared to the conventional product because of the remarkable improvement of workability of polymer concrete using spherical fly ash and atomizing reduction steel slag instead of calcium carbonate (filler) and river sand (fine aggregate).

• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.549-555
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• 2007

Although blast furnace slag has been widely used in concrete as a cementitious admixture or aggregate for many years, the slowly cooled steel slag is not used in concrete but mainly in road. Its use in concrete operates problem such as the lack of volume stability due to high free CaO content, which can be potentially hazardous in concrete. However, the rapidly cooled steel slag by atomization has a low free CaO content, a high density, and a spherical shape, so it is expected to use in concrete so much. This paper is to understand the probability that the rapid cooled steel slag can replace the silica sand used as aggregate in the epoxy mortar. We did the experimental study on the properties of the epoxy mortar having various replacement proportion of rapidly cooled steel slag. This study shown that increasing content of the rapidly cooled steel slag in epoxy mortar lead to increase largely the passing time of nozzle by O-lot, compressive strength and flexural strength. However except the flow is almost same level. So we understand that the rapidly cooled steel slag has positive effect on increasing of properties in epoxy mortar.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.557-563
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• 2008

Recently, the amount of disposed construction materials like demolished concrete is growing fast and the shortage of natural concrete aggregate is becoming serious. Therefore, recycling of aggregate extracted from the demolished concrete is getting important and use of the recycled aggregate for concrete has been seriously considered. However, the use of the recycled aggregate even for low performance concrete is very limited because recycled aggregate which contains large amount of old mortar has very low quality. Therefore, removing the paste sticked to the recycled aggregate is very important in the manufacturing of high quality recycled aggregate. We have studied a series of research according to complex crushing method, which is removed the ingredient of cement paste from recycled fine aggregate using both the low speed wet abrasion crusher as mechanical process and the acid treatment as chemical processes. This paper is to analyze the quality of the recycled fine aggregate produced by those complex method and investigate optimum manufacturing condition for recycled fine aggregate by the design of experiments. The experimental parameters considered are water ratio, coase aggregate ratio, and abrasion time. As a result, data concerning the properties of recycled sand were obtained. It was found that high quality recycled fine aggregate could be to obtain at the condition of the fifteen minute of abrasion-crusher time and the over 1.0 of recycled coarse aggregate ratio.