This paper presents nonlinear finite element analysis of eccentrically loaded circular Reinforced Concrete (RC) column confined with Carbon Fiber Reinforced Polymer (CFRP) wraps. The concrete constitutive model uses a plasticityfracture model which is restraint sensitive, utilize a non-constant plastic dilation rate, and is able to simulate the plastic volumetric compaction of concrete core under high confining pressure. For validation of the models, two available specimens from the literature are used in the validations. Excellent agreement between the numerical models and the available test results are obtained in this study. A detailed investigation on the confinement effectiveness of both external and internal confining devices are presented and discussed. This discussion of the confinement effectiveness is important to be included in the design formula.
This study aims to predict the compressive strength of existing concrete without using destructive tests which can damage the surface of the concrete. Destructive testing has the disadvantage of damaging the surface of the concrete, requires a long time and need expensive cost, while the Non Destructive Test (NDT) has the advantage of not damaging the surface of the concrete and faster when combined with the Artificial Neural Network (ANN) method. In this research, the Non Destructive Test (NDT) result such as hammer test and UPV were combined with concrete mix design properties and used to predict the compressive strength of concrete at three and 28 days. The Artificial Neural Network (ANN) method is used to make correlation of mix design properties data and NDT. In this study experimental tests were performed using variation of design parameters such as water per cement ratio and weight ratio of fly ash. The water per cement ratio used in this research was in range 0.45 until 0.55. Furthermore, the weight ratio of fly ash was in range 0% until 25%. Based on the modeling result using ANN method, it found that that the neural network method successfully predicts the compressive strength of concrete at three and 28 days with the mean square error (MSE) value and regression of concrete at three days are5.83 and 0.89 respectively. While at 28 days the MSE and regression value are 4.7 and 0.87 respectively.
This paper presents nonlinear finite element analysis of eccentrically loaded circular Reinforced Concrete (RC) column confined with Carbon Fiber Reinforced Polymer (CFRP). The purpose of this study is to validate the proposed plasticity-fracture model of Piscesa et. al. (2019) to model RC column confined with CFRP under eccentric loading. The software used in the simulation is and inhouse finite element package called 3D-NFLEA. Two available specimens in the literature are investigated and an existing numerical result is also included for comparison purposes. From the analysis and investigation, it was found out that the negative effect of confinement at the outer concrete region was caused by significant difference between the concrete dilation rate at the inner to the outer concrete core region. In addition, From the comparison, close agreement between the numerical models and the available test result are discovered in this study. As for the column ductility, it was found out that the column ductility was higher for column with larger initial load eccentricity.
For concrete planners and salt farmers know the distribution of sulfate in sea water becomes very important as a basis for the manufacture of concrete and as a planning analysis of salt-making. Based on this need to be done mapping the distribution of sulfate concentrations in surface sea water. In addition to the way the analysis in the laboratory, suspected sulfate can be done using an estimation algorithm as a remote sensing technique that results are presented in the form of geographic information systems. With remote sensing techniques will be obtained regional information sulfate at the sea surface since using Landsat 8 satellite recording results.The mapping of sulfate in the straits of Madura Island with Landsat 8 OLI imagery on July 26, 2018, obtained the minimal value was 2078.89 and the maximal value 2429.89.The highest sulfate concentration is in the Ujung-Kamal port area.When using SNI 2847: 2013 / ACI 318M-11 sulfate exposure in the Madura Strait includes a class of S2 with severe severity.
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