• Title/Summary/Keyword: Roller compacted concrete

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Investigation on the Repeatability of Modified Proctor Test for Roller Compacted Concrete Pavement (롤러 전압 콘크리트 포장을 위한 수정다짐시험의 반복재현성 고찰)

  • Hwang, Seok Hee;Rith, Makara;Hong, Seong Jae;Lee, Seung Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.4
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    • pp.931-940
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    • 2015
  • Roller Compacted Concrete Pavement (RCCP), is a type of pavement using compaction roller and asphalt finisher on concrete mixture that contains low amount of water. RCCP strength and durability are greatly affected by compaction level. Quality control is performed by ensuring the degree of compaction at site based on dry density. In the field, Modified Proctor Test is used in order to obtain optimum dry density. However, there is no clear compaction curve analysis criteria of Modified Proctor Test for RCCP. In this study, compaction curve built by three samples of Modified Proctor Test was produced and it was used to compare with compaction curve contented lower number of samples (one and two samples) in order to analyze their reliability. Thus, a conclusion was drawn from the results; by comparing to the result from Modified Proctor Test of three samples, the use of two samples represented result with only 0.5% of error which means the reliability is 99.5%.

Thermal Stresses of Roller Compacted Concrete Dam Considering Construction Sequence and Seasonal Temperature (시공단계 및 계절별 온도영향을 고려한 롤러다짐콘크리트댐의 온도응력 해석)

  • Cha, Soo-Won;Jang, Bong-Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6A
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    • pp.881-891
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    • 2008
  • The purpose of the present study is to investigate the influence of seasonal temperature variation on the thermal stresses in roller compacted concrete dam(RCD) structures. Using the finite element code, DIANA performs 2-D transient temperature and resultant stress analysis for RCD. Time variability of the mesh geometry is considered in order to simulate successive phases of the structure's construction. The main analysis variables are construction sequence, concrete temperature and ambient temperature. The results show principal tensile stress of hot-weathering concrete is higher than that of cold-weathering concrete. In some case the index of thermal cracking excesses 1.0, RCD also needs thermal management on placing temperature according to weather condition.

Evaluating the performance AASHTOWare's mechanistic-empirical approach for roller-compacted concrete roadways

  • Emin Sengun
    • Computers and Concrete
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    • v.33 no.4
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    • pp.445-469
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    • 2024
  • The Federal Highway Administration (FHWA) has recommended the use of AASHTOWare Pavement Mechanistic-Empirical Design (PMED) software for Roller-Compacted Concrete (RCC) pavement design, but specific calibration for RCC is missing. This study investigates the software's capacity to predict the long-term performance of RCC roadways within the framework of conventional concrete pavement calibration. By reanalyzing existing RCC projects in several U.S. states: Colorado, Arkansas, South Carolina, Texas, and Illinois, the study highlights the need for specific calibration tailored to the unique characteristics of RCC. Field observations have emphasized occurrence of early distresses in RCC pavements, particularly transverse-cracking and joint-related issues. Despite data challenges, the AASHTOWare PMED software exhibits notable correlation between its long-term predictions and actual field performance in RCC roadways. This study stresses that RCC applications with insufficient joint spacing and thickness are prone to premature cracking. To enhance the accuracy of RCC pavement design, it is essential to discuss the inclusion of RCC as a dedicated rigid pavement option in AASHTOWare PMED. This becomes particularly crucial when the rising popularity of RCC roadways in the U.S. and Canada is considered. Such an inclusion would solidify RCC as a viable third option alongside Jointed Plain Concrete Pavements (JPCP) and Continuously Reinforced Concrete Pavements (CRCP) for design and deployment of rigid pavements. The research presents a roadmap for future calibration endeavors and advocates for the integration of RCC pavement as a distinct pavement type within the software. This approach holds promise for achieving more precise RCC pavement design and performance predictions.

Analysis of Relationship Between Compressive Strength and Compaction Ratio of Roller-Compacted Concrete Pavement (포장용 롤러전압콘크리트의 다짐도와 압축강도의 상관관계 분석)

  • Chung, Gun Woo;Song, Si Hoon;Lee, Seung Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.6
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    • pp.1117-1123
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    • 2016
  • Roller-Compacted Concrete Pavement (RCCP) is a type of pavement that shares conventional concrete pavement material characteristics and asphalt pavement construction characteristics. Even though RCCP is compacted in the same way and have similar aggregate gradation to asphalt pavements, its materials and structural performance properties are similar to those of conventional concrete pavement. With cement hydration and aggregate interlock, Roller-Compacted Concrete or RCC can provide strength properties equal to those of conventional concrete with low cement content. Therefore, compaction ratio of RCC can highly influence on its strength. In general, 95% of compaction ratio is required for proper strength development. RCC strength can be highly influenced by compaction energy which depends on compaction equipment and compaction method. Therefore, it is necessary to analyze the relationship between compressive strength and compaction ratio of RCC. RCCP specimens were produced at different compaction ratio by using different compaction methods and energies. The compaction ratio was defined by the ratio of the specimen's dry density and its maximum dry density. The maximum dry density was obtained from Modified Proctor test. 28 days compressive strength corresponding to each compaction ratio case was tested. Finally, the relationship between compressive strength and compaction ratio can be analyzed. For application of roller-compacted concrete in domestic construction site, the relationship is important for field compaction management.

Modeling of combined thermal and mechanical action in roller compacted concrete dam by three-dimensional finite element method

  • Abdulrazeg, A.A.;Noorzaei, J.;Mohammed, T.A.;Jaafar, M.S.
    • Structural Engineering and Mechanics
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    • v.47 no.1
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    • pp.1-25
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    • 2013
  • A combined thermal and mechanical action in roller compacted concrete (RCC) dam analysis is carried out using a three-dimensional finite element method. In this work a numerical procedure for the simulation of construction process and service life of RCC dams is presented. It takes into account the more relevant features of the behavior of concrete such as hydration, ageing and creep. A viscoelastic model, including ageing effects and thermal dependent properties is adopted for the concrete. The different isothermal temperature influence on creep and elastic modulus is taken into account by the maturity concept, and the influence of the change of temperature on creep is considered by introducing a transient thermal creep term. Crack index is used to assess the risk of occurrence of crack either at short or long term. This study demonstrates that, the increase of the elastic modulus has been accelerated due to the high temperature of hydration at the initial stage, and consequently stresses are increased.

Degradation of roller compacted concrete subjected to low-velocity fatigue impacts and salt spray cycles

  • Gao, Longxin;Lai, Yong;Zhang, Huigui;Zhang, Jingsong;Zhang, Wuman
    • Advances in concrete construction
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    • v.12 no.5
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    • pp.411-418
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    • 2021
  • Roller compacted concrete (RCC) used in the island reef airport runway will be subjected to the coupling actions of the fatigue impacts and the salt spray cycles, which will accelerate the deterioration of runway concrete and even threaten the flight safety. A cyclic impact testing machine and a climatic chamber were used to simulate the low-velocity fatigue impact and the salt spray cycles, respectively. The physical properties, the microstructures and the porosity of RCC were investigated. The results show the flexural strength firstly increases and then decreases with the increase of the fatigue impacts and the salt spray cycles. However, the decrease in the flexural strength is significantly earlier than the compressive strength of RCC only subjected to the salt spray cycles. The chlorine, sulfur and magnesium elements significantly increase in the pores of RCC subjected to 30000 fatigue impacts and 300 salt spray cycles, which causes the decrease in the porosity of RCC. The coupling effects of the fatigue impacts and the salt spray cycles in the later period accelerates the deterioration of RCC.

Evaluation of the Performance on Coating on Roller Compacted Concrete Pavement for Bike Roads (자전거도로용 롤러 전압 콘크리트 포장의 코팅에 따른 성능 평가)

  • Lee, Chang-Ho;Lee, Seung-Woo;Kim, Seong-Kil
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.79-86
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    • 2011
  • Recently, usage bicycle is encouraged to reduce fuel consumption and air pollution. For this purpose, bike road constructions are actively performed. However, types of pavement used in bike roads have high construction cost and performance comparing the required capacity of bike roads. Thus, an economical pavement type for construction is necessary for the effective development. Roller compacted concrete pavement have good requirements, such as easy construction and low costs, high structural performance of hydration and internal communication aggregation on compaction for bicycle roads. However, the pool landscape surface and resistance to deicer damage cannot be applied to the construction of bicycle roads. Thus, for solving this problem used coating which may have effect of improving the landscape and environmental resistance. To examine this effect were evaluated performance of roller compacted concrete pavement on the coating.

Mix proportions of Concrete for Roller Compacted Concrete Dam Application (RCC 댐 콘크리트의 배합비 도출에 관한 연구)

  • 원종필;윤종환;황금식;장필성;김완영;정우성
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.997-1002
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    • 2003
  • Roller-compacted concrete(RCC) dam is a new type that combines advantages of earthfill dam and concrete dam in construction, This method save cost due to their rapid method of construction. RCC is, used in RCC dams, no-slump concrete so it is different that measure method of consistency and mixture properties compare with conventional mass concrete, There are existing two major design method, which one used in USA the other used in Japan. The results obtained in this study would be useful in establishing mixture proportions for dam concrete for RCC dams by apply method of compound their merit.

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Earthquake response of roller compacted concrete dams including galleries

  • Karabulut, Muhammet;Kartal, Murat Emre
    • Structural Engineering and Mechanics
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    • v.72 no.2
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    • pp.141-153
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    • 2019
  • The effect of galleries on the earthquake behavior of dams should be investigated to obtain more realistic results. Therefore, a roller compacted concrete (RCC) dam with and without galleries are examined under ground motion effects. For this purpose, Cine RCC dam constructed in Aydın, Turkey, is selected in applications. The optimal mesh around galleries is investigated to obtain the most realistic results. Two-dimensional finite element models of Cine RCC dam with and without galleries are prepared by using ANSYS software. Empty and full reservoir conditions were taken into account in the time-history analyses. Hydrodynamic effect of the reservoir water was taken into account considering two-dimensional fluid finite elements based on the Lagrangian approach. It is examined that how principle stresses and displacements change by height and during earthquake. The dam-foundation-reservoir interaction was taken into consideration with contact-target element pairs. The displacements and principle stress components obtained from the linear analyses are compared each other for various cases of reservoir water and galleries. According to numerical analyses, the effect of galleries is clear on the response of RCC dam. Besides, hydrodynamic water effect obviously increases the principle stress components and horizontal displacements of the dam.

Roller compacted concrete pavements reinforced with steel and polypropylene fibers

  • Madhkhan, Morteza;Azizkhani, Rasool;Torki, Mohammad E.
    • Structural Engineering and Mechanics
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    • v.40 no.2
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    • pp.149-165
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    • 2011
  • In this paper, the effects of both pozzolans and (steel and poly-propylene) fibers on the mechanical properties of roller compacted concrete are studied. Specimens for the experiments were made using a soil-based approach; thus, the Kango's vibration hammer was used for compaction. The tests in the first stage were carried out to determine the optimal moisture requirements for mix designs using cubic $150{\times}150{\times}150$ mm specimens. In the tests of the second stage, the mechanical behaviors of the main specimens made using the optimal moisture obtained in the previous stage were evaluated using 28, 90, and 210 day cubic specimens. The mechanical properties of RCC pavements were evaluated using a soil-based compaction method and the optimum moisture content obtained from the pertaining experiments, and by adding different percentages of Iranian pozzolans as well as different amounts of steel fibers, each one accompanied by 0.1% of poly-propylene fibers. Using pozzolans, maximum increase in compressive strength was observed to occur between 28 and 90 days of age, rupture modulus was found to decrease, but toughness indices did not change considerably. The influence of steel fibers on compressive strength was often more significant than that of PP fibers, but neither steel nor PP fibers did contribute to increase in the rupture modulus independently. Also, the toughness indices increased when steel fibers were used.