• 제목/요약/키워드: compressive performance

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재래 및 비파괴검사를 이용한 고강도 콘크리트의 재료특성에 관한 연구 (Material property evaluation of high strength concrete using conventional and nondestructive testing method)

  • 조영상
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.629-634
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    • 2001
  • This study is to characterize the material property of early age high performance concrete emphasizing compressive strength using nondestructive testing methods. Three high performance concrete slabs of 600, 850 and 1100kg/$cm^{2}$ compressive strengths were prepared together with cylinders from same batches. Cylinder tests were peformed at the ages of 7, 14, 21 and 28 days after pouring. Using the impact echo method, the compression wave velocities were obtained based on different high performance concrete ages and compressive strengths. The equation to obtain the compressive strengths of high performance concrete has been developed using the obtained compression wave velocities. Using the SASW (spectral analysis of surface wave) method, the equation have also been developed to obtain the compressive strengths of high performance concrete based on the surface wave velocities.

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Assessment of compressive strength of high-performance concrete using soft computing approaches

  • Chukwuemeka Daniel;Jitendra Khatti;Kamaldeep Singh Grover
    • Computers and Concrete
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    • 제33권1호
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    • pp.55-75
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    • 2024
  • The present study introduces an optimum performance soft computing model for predicting the compressive strength of high-performance concrete (HPC) by comparing models based on conventional (kernel-based, covariance function-based, and tree-based), advanced machine (least square support vector machine-LSSVM and minimax probability machine regressor-MPMR), and deep (artificial neural network-ANN) learning approaches using a common database for the first time. A compressive strength database, having results of 1030 concrete samples, has been compiled from the literature and preprocessed. For the purpose of training, testing, and validation of soft computing models, 803, 101, and 101 data points have been selected arbitrarily from preprocessed data points, i.e., 1005. Thirteen performance metrics, including three new metrics, i.e., a20-index, index of agreement, and index of scatter, have been implemented for each model. The performance comparison reveals that the SVM (kernel-based), ET (tree-based), MPMR (advanced), and ANN (deep) models have achieved higher performance in predicting the compressive strength of HPC. From the overall analysis of performance, accuracy, Taylor plot, accuracy metric, regression error characteristics curve, Anderson-Darling, Wilcoxon, Uncertainty, and reliability, it has been observed that model CS4 based on the ensemble tree has been recognized as an optimum performance model with higher performance, i.e., a correlation coefficient of 0.9352, root mean square error of 5.76 MPa, and mean absolute error of 4.1069 MPa. The present study also reveals that multicollinearity affects the prediction accuracy of Gaussian process regression, decision tree, multilinear regression, and adaptive boosting regressor models, novel research in compressive strength prediction of HPC. The cosine sensitivity analysis reveals that the prediction of compressive strength of HPC is highly affected by cement content, fine aggregate, coarse aggregate, and water content.

180MPa 초고성능 콘크리트의 압축 부재에의 적용성에 대한 연구 (A Study for Application of 180 MPa Ultra High Performance Concrete to Compressive Members)

  • 민경환;최홍식
    • 한국산학기술학회논문지
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    • 제16권7호
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    • pp.4930-4935
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    • 2015
  • 180MPa급 초고성능 콘크리트는 높은 압축강도로 인해 압축 부재에 대한 연구 결과가 부족한 실정이다. 본 연구에서는 UHPC의 적용성 향상을 위해 트윈 샤프트 믹서 배치 플랜트에서 생산성을 평가하였다. 또한 설계 방안을 제시하기 위한 기초 자료를 획득하기 위해 사각 기둥과 원형 기둥에 대한 중심축하중 실험을 수행하여 파괴 형태와 거동을 평가하였다.

콘크리트 초기 품질관리를 위한 CIMS의 개발성능 Test (Performance test of Concrete IoT Management System for concrete early-age quality control)

  • 이영준;최윤호;서항구;현승용;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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    • pp.161-162
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    • 2019
  • The aim of the research is analyzing the performance of the concrete IoT management system invented with similar technique from 'G' company to certify the performance of CIMS. As a results, the compressive strength assessing performance was compared. Since both systems assess concrete compressive strength with maturity method based on measured concrete temperature, both systems measured concrete temperature similarly, and maturity was calculated similarly. Therefore, the assumed compressive strength values were similar for both systems. Therefore, through the test, compressive strength assessing performance of CIMS was considered as a similar level of the 'G' company's system. Furthermore, it is considered that the CIMS has an additional advantage of reusability, adding capability of additional sensor, and wider range of Bluetooth communication.

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고성능 표면침투제가 도포된 콘크리트의 물리특성 (Physical Characteristics of Concrete Coated High Performance Surface Penetration Agency)

  • 유성원;서정인;하헌재;이상민;이상근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.809-812
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    • 2004
  • The evaluation of characteristics of concrete coated by high performance surface penetration agency was examined through various tests, i.e., compressive strength, penetration depth, water and air permeability, absorption according to various high performance surface penetration agencies and various compressive strengths of base concrete. The 4 types of high performance surface penetration agencies were used i.e., organic, inorganic, water soluble, and alcohol soluble. And 3 types of compressive strength of base concrete were used such as 21, 24 and 30 MPa. The characteristics of concrete coated high performance surface penetration agency was more improved than that of non-coated concrete, and especially, water soluble inorganic agency was most effective. And if compressive strength of base concrete was low, the improved effects would be larger.

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거리-도플러 추정을 위한 압축 센싱 알고리즘의 계산 성능과 정확도 (Computational performance and accuracy of compressive sensing algorithms for range-Doppler estimation)

  • 이현규;이근화;홍우영;임준석;정명준
    • 한국음향학회지
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    • 제38권5호
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    • pp.534-542
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    • 2019
  • 능동소나에서는 표적의 거리 도플러 정보를 탐지하기 위해 여러 가지 기법을 사용한다. 그중 압축 센싱을 적용한 기법은 기존의 방식보다 더욱 정밀한 탐지가 가능하며 우수한 성능을 나타낸다. 능동 소나의 거리 도플러 추정에 적용할 수 있는 압축 센싱 알고리즘은 여러 가지 있다. 압축 센싱 알고리즘 마다 계산 성능이 다르며 압축 센싱 알고리즘에 따라 신호 대 잡음비와 센싱 행렬의 코히런스가 거리 도플러 추정에 미치는 영향의 정도가 다르다. 본 논문은 능동 소나의 거리 도플러 추정을 위한 여러 가지 압축 센싱 알고리즘의 계산 성능과 정확도를 비교, 분석하였다. 여러 신호대 잡음비, 상호간섭성 값에 대한 OMP(Orthogonal Matching Pursuit), CoSaMP(Compressive Sampling Matching Pursuit), BPDN(CVX)(Basis Pursuit Denoising), LARS(Least Angle Regression) 알고리즘의 추정 성능을 확인하였으며, 상황에 따른 최적의 압축 센싱 알고리즘을 보인다.

Comparative analysis of multiple mathematical models for prediction of consistency and compressive strength of ultra-high performance concrete

  • Alireza Habibi;Meysam Mollazadeh;Aryan Bazrafkan;Naida Ademovic
    • Coupled systems mechanics
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    • 제12권6호
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    • pp.539-555
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    • 2023
  • Although some prediction models have successfully developed for ultra-high performance concrete (UHPC), they do not provide insights and explicit relations between all constituents and its consistency, and compressive strength. In the present study, based on the experimental results, several mathematical models have been evaluated to predict the consistency and the 28-day compressive strength of UHPC. The models used were Linear, Logarithmic, Inverse, Power, Compound, Quadratic, Cubic, Mixed, Sinusoidal and Cosine equations. The applicability and accuracy of these models were investigated using experimental data, which were collected from literature. The comparisons between the models and the experimental results confirm that the majority of models give acceptable prediction with a high accuracy and trivial error rates, except Linear, Mixed, Sinusoidal and Cosine equations. The assessment of the models using numerical methods revealed that the Quadratic and Inverse equations based models provide the highest predictability of the compressive strength at 28 days and consistency, respectively. Hence, they can be used as a reliable tool in mixture design of the UHPC.

고성능 하이브리드 섬유보강 콘크리트의 압축 및 인장 거동 (Compressive and Tensile Behaviors of High Performance Hybrid Fiber Reinforced Concrete)

  • 권순오;배수호;이현진
    • 한국건설순환자원학회논문집
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    • 제8권4호
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    • pp.458-466
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    • 2020
  • 이 연구의 목적은 비정질 강섬유와 폴리아미드 섬유를 이용한 고성능 하이브리드 섬유보강 콘크리트의 압축 및 인장 거동을 평가하는 것이다. 이를 위하여 목표 압축강도 40MPa 및 60MPa 각각에 대해서 비정질 강섬유와 폴리아미드 섬유를 총 부피비로 1.0% 혼입한 고성능 하이브리드 섬유보강 콘크리트를 제작한 후 압축강도, 압축인성, 직접인장강도 및 응력-변형률 특징 등의 압축 및 인장 거동을 평가하였다. 그 결과, 고성능 하이브리드 섬유보강 콘크리트의 압축강도는 플레인 콘크리크보다 다소 감소하였으나, 압축인성, 압축인성 비, 직접인장강도는 크게 증가하는 것으로 나타났다. 또한 압축 및 인장 시험시 플레인 콘크리트는 최대응력 이후 취성파괴를 나타냈으나, HPHFRC는 변형연화 현상을 나타내어, 압축 및 인장 거동이 크게 개선되는 것으로 나타났다.

Finite element analysis and theoretical modeling of GFRP-reinforced concrete compressive components having waste tire rubber aggregates

  • Mohamed Hechmi El Ouni;Ali Raza
    • Steel and Composite Structures
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    • 제52권1호
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    • pp.57-76
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    • 2024
  • The management of waste tire rubber has become a pressing environmental and health issue, requiring sustainable solutions to mitigate fire hazards and conserve natural resources. The performance of waste materials in structural components needs to be investigated to fabricate sustainable structures. This study aims to investigate the behavior of glass fiber reinforced polymer (GFRP) reinforced rubberized concrete (GRRC) compressive components under compressive loads. Nine GRRC circular compressive components, varying in longitudinal and transverse reinforcement ratios, were constructed. A 3D nonlinear finite element model (FEM) was proposed by means of the ABAQUS software to simulate the behavior of the GRRC compressive components. A comprehensive parametric analysis was conducted to assess the impact of different parameters on the performance of GRRC compressive components. The experimental findings demonstrated that reducing the spacing of GFRP stirrups enhanced the ductility of GRRC compressive components, while the addition of rubberized concrete further improved their ductility. Failure in GRRC compressive components occurred in a compressive columnar manner, characterized by vertical cracks and increased deformability. The finite element simulations closely matched the experimental results. The proposed empirical model, based on 600 test samples and considering the lateral confinement effect of FRP stirrups, demonstrated higher accuracy (R2 = 0.835, MSE = 171.296, MAE = 203.549, RMSE = 195.438) than previous models.

Development of high-performance heavy density concrete using different aggregates for gamma-ray shielding

  • Ouda, Ahmed S.
    • Advances in materials Research
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    • 제3권2호
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    • pp.61-75
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    • 2014
  • This study aimed to investigate the suitability of some concrete components for producing "high-performance heavy density concrete" using different types of aggregates that could enhances the shielding efficiency against ${\gamma}$-rays. 15 mixes were prepared using barite, magnetite, goethite and serpentine aggregates along with 10% silica fume, 20% fly ash and 30% blast furnace slag to total OPC content for each mix. The mixes were subjected to compressive strength at 7, 28 and 90 days. In some mixes, compressive strengths were also tested up to 90 days upon replacing sand with the fine portions of magnetite, barite and goethite. The mixes containing magnetite along with 10% SF reaches the highest compressive strength exceeding over M60 requirement by 14% after 28 days. Whereas, the compressive strength of concrete containing barite was very close to M60 and exceeds upon continuing for 90 days. Also, the compressive strength of high-performance concrete incorporating magnetite fine aggregate was significantly higher than that containing sand by 23%. On the other hand, concrete made with magnetite fine aggregate had higher physico-mechanical properties than that containing barite and goethite. High-performance concrete incorporating magnetite fine aggregate enhances the shielding efficiency against ${\gamma}$-rays.