• Polymer(Korea)
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• v.32 no.6
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• pp.555-560
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• 2008

Polymer-modified mortars have been largely used as paving materials, flooring, waterproofing material, adhesives, anticorrosive linings, deck coverings, and other various materials. The various types and properties of the mixed polymer largely affect the characteristics of polymer-modified mortar that has been mixed with polymer latexes. Consequently, its application purposes are varied according to these properties. This paper investigates the typical properties of polymer-modified mortars that contain styrene and butyl acrylate latexes and styrene butadiene rubber. They are then tested to obtain air contents, water-cement ratios, flexural and compressive strengths, water absorption, and chloride-ion penetration. From the test results, the superior flexural strength of polymer-modified mortars is obtained at a S/BA-2 and a polymer-cement ratio of 20%. And, the water absorption and chloride ion penetration depth are greatly affected by the polymer-cement ratio rather than the types of polymer. In the polymer-modified mortar and concrete structures, aggregates are bound by such a co-matrix phase, resulting in the superior properties of polymer-modified mortar and concrete compared to conventional mortar and concrete.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.571-579
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• 2016

RS-LMC (Rapid Setting Latex Modified Concrete) has been widely used as repair material for bridge deck overlay or rehabilitation, because the overlaid pavement could be opened to the traffic after 3 hours of curing. Although the field performance of RS-LMC generally indicates that it has an excellent bonding to the substrate and shows a long term performance, the crack by vibration of vehicles have been happened on the overlay of bridges in technical reports. In this study, experimental research was carried out to evaluate the vibration properties of RS-LMC overlays by using P.S.T (Pavement Shaking Table). Total 12 specimens were tested and the variables are Latex-cement ratio (L/C) and amplitude of vibration. The result shows that the number of cracks and the total length of cracks are reduced as the increase of Latex-cement ratio (L/C) until 15%. And the crack occurs at a very small strain than the proposed values by Walter, D, G and design codes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.203-214
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• 2024

Ports often suffer pavement damage due to soft ground and heavy equipment operations, leading to issues such as differential settlement and cracks. In this study, we developed port concrete blocks and applied them to a port in two configurations to figure out settlement characteristics. Falling weight deflectometer (FWD) tests on asphalt pavement and block pavements were conducted to figure out deflection and bearing capacity. The block pavement with the cement treated base showed improved bearing capacity with the port operation since lower settlements were detected than asphalt pavement. In the cement treated base, the relative deflection ratio to asphalt concrete pavement was less than 1, indicating enhanced bearing capacity. LiDAR measurements identified multiple settlements in the crushed-stone base due to surface loads after construction. Both relative deflection ratio and LiDAR measurements suggested that block pavement can be widely applied to various port sites with its applicability and bearing capacity of cement-treated base.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.533-536
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• 2008

This study is the application of phosphate magnesia cement for solidification of soils. The object of the study is the application of the pavment of the farm roads. The new pavement method must be environmental, ecologic and durable. So, for solidification of farm road's soil, we use magnesia cement as quick setting, high strength materials. At magnesia phosphate cement, mixing ratio of mono ammonium phosphate and magnesia is 4:6 and w/b is 50 wt%, it show 14 MPa of compressive strength, and high hydration heat. Solidified soils that mixing ratios of magnesia cement and soil are 4:6 and 5:5 have very high durability for freezing and thawing.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.135-139
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• 1993

It was found in a series of test sections constructed in Houston, Texas that (1) concrete placement in hot season resulted in much more early-age cracks than that in cool season, and that, (2) for the hot season placement, pavements placed in the morning showed more early-age cracks than those placed in the afternoon. Early-age cracks, in this study, are defined as cracks occurring within a few days after construction. Since the early-age cracks have a tendency to be meandering and the crack widths are relatively wide, they may give an adverse effect on the long-term performance of the pavement. The objectives of this study are to recognize the effects of placement time on the early-age crack patterns and to find the reason of the effects. The effects are explained in this study by relating hydration of cement and surrounding temperature conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.4
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• pp.11-21
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• 1988

In twentieth century, a rigid pavement composed of a series of thin Portland Cement Concrete has been accepted due to the desirable structural strength of concrete, durability and economy. However, despite of precise design and construction of concrete highway pavements, some of concrete pavements (example : Interstate-l0 and 75 in U.S.A, 88 Olympic express highway and Jung-bu express highway in Korea) has already shown severe signs of longitudinal and transverse cracking, faulting, and pumping before the end of their intended service life. This highlights the need for better understanding of concrete pavement behavior using structural analysis program. For these reasons, this research was performed to study an analytical behavior of concrete pavements, especially for the effects of skewed joints on concrete pavements. Subsequently, this research should give better understanding of concrete pavement behavior to the highway engineers and provide effective remedies to the concrete highway pavements.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.5
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• pp.59-67
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• 2012

During the manufacturing of Portland cement, CO2 gas is also necessarily produced through both decarbonation of calcium carbonate and kiln burning. By partially replacing the Portland cement with limestone powder, which is an inert filler in a concrete mixture, CO2 consumption can be reduced in a construction field. This study is to investigate the fundamental durability characteristics of limestone powder added concrete. Experimental variable was the replacement ratio of limestone powder from 0% to 25% with 5% increment. Durability characteristics were investigated by resistance to freeze-thaw, alkali-silica reaction and de-icing chemical in addition to the properties of fresh concrete. From test results, it was observed that the addition of limestone powder did not significantly affect the resistance to freeze-thaw reaction and de-icing chemical. The addition of limestone powder reduced the occurrence potential of alkali-silica reaction by reducing an alkali content in Portland cement.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.437-438
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• 2022

본 논문에서는 상변환 재료를 이용하여 동절기에 발생하는 도로포장의 블랙아이스 현상을 저감시키기 위한 기초연구를 진행하였다. 콘크리트 내에서 누출을 막기 위해 마이크로 캡슐화된 상변환 재료를 이용했으며 초기 개발단계인 만큼 페이스트 단계에서 실험을 진행 하였다. 실험은 초기 수화거동에서의 수화열 발생 경향을 분석하기 위해서 미소수화열 측정 실험과 반복되는 온도변화 환경에서의 상변환재료 캡슐의 안정성을 분석하기 위해 주사전자현미경을 이용하였다. 상변환 재료의 열에너지 저장 및 방출 능력은 시멘트의 미소수화열 발생에 상당한 변화를 주었으며, 온도변화에 의한 상변환 재료 캡슐계면의 이상은 발생하지 않는 것으로 나타났다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.4
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• pp.73-82
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• 1989

Various analytical procedures for the structural behavior of concrete pavement system are studied in order to identify a suitable method which will be incorperated in the pavement management system using nondestructive test and mechanistic evaluation. A typical four layered system is adopted and analyzed using 3 dimensional finite elements, plane strain elements, plates with Winkler foundation, and plates with Burmister foundation. Numerical analysis results of various structural analysis procedures are compared and analized based on displacements and stresses. It is concluded, after analysis of merits and demetits of the procedures, that Burmister foundation analysis procedure is the most sui-table procedure for implementation for the analysis of stresses and displacements because of its accuracy and simplicity.

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.471-478
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• 2009