Current Issue : January - March Volume : 2017 Issue Number : 1 Articles : 5 Articles
This paper aims to provide guidelines for the numerical modeling of reinforced concrete (RC) frame elements in order\nto assess the seismic performance of structures. Several types of numerical models RC frame elements are available in nonlinear\nstructural analysis packages. Since these numerical models are formulated based on different assumption and theories, the models\naccuracy, computing time, and applicability vary, which poses a great difficulty to practicing engineering and limits their confidence\nin the analysis resultants. In this study, the applicability of four representative numerical models of RC frame elements is\nevaluated through comparison with experimental results of four-storey bare frame available from European Laboratory for\nStructural Assessment. The accuracy of a numerical model is evaluated according to the top displacement, interstorey drift,\nMaximum storey shear, damage pattern and energy dissipation capacity of the frame structure. The results obtained allow a better\nunderstanding of the characteristics and potentialities of all procedures, helping the user to choose the best approach to perform\nnonlinear analysis....
The objective of this paper is to investigate the effect of thickness and moisture on temperature distributions of\nreinforced concrete walls under fire conditions. Toward this goal, the first three wall specimens having different thicknesses are\nheated for 2 h according to ISO standard heating curve and the temperature distribution through the wall thickness is measured.\nSince the thermal behavior of the tested walls is influenced by thickness, as well as moisture content, three additional walls are\nprepared and preheated to reduce moisture content and then tested under fire exposure. The experimental results clearly show the\ntemperatures measured close to the fire exposed surface of the thickest wall with 250 mm thickness is the highest in the\ntemperatures measured at the same location of the thinner wall with 150 mm thickness because of the moisture clog that is formed\ninside the wall with 250 mm of thickness. This prevents heat being transferred to the opposite side of the heated surface. This is\nalso confirmed by the thermal behavior of the preheated walls, showing that the temperature is well distributed in the preheated\nwalls as compared to that in non-preheated walls. Finite element models including moisture clog zone are generated to simulate fire\ntests with consideration of moisture clog effect. The temperature distributions of the models predicted from the transient heat\nanalyses are compared with experimental results and show good agreements. In addition, parametric studies are performed with\nvarious moisture contents in order to investigate effect of moisture contents on the thermal behaviors of the concrete walls...
When the energy performance of concrete is substantially higher than that of normal type concrete, such concrete is\nregarded as energy efficient concrete (WBSCSD 2009). An experimental study was conducted to investigate mechanical properties\nof energy efficient concrete with binary, ternary and quaternary admixture at different curing ages. Slump test for workability and\nair content test were performed on fresh concretes. Compressive strength, splitting tensile strength were made on hardened\nconcrete specimens. The mechanical properties of concrete were compared with predicted values by ACI 363R-84 Code, NZS\n3101-95 Code, CSA A23.3-94 Code, CEB-FIP Model, EN 1991, EC 2-02, AIJ Code, JSCE Code, and KCI Code. The use of silica\nfume increased the compressive strengths, splitting tensile strengths, modulus of elasticities and Poisson�s ratios. On the other\nhand, the compressive strength and splitting tensile strength decreased with increasing fly ash....
Through applying MSC.Marc nonlinear finite element software,\nthis research is to explore the ductility performance of steel reinforced\nconcrete T-shaped columns under reciprocating loading. The result shows\nthat the MSC.Marc calculation results are quite consistent with the\nexperimental data, and can objectively reflect the mechanical properties of\nsteel reinforced concrete special-shaped columns. These mean that the\nMSC.Marc software can be used for performing simulation analysis on the\nsteel reinforced concrete special-shaped column hysteretic performance.\nThrough changing the axial compression ratio, shear span ratio and load\nangle to research the ductility performance of steel reinforced concrete\nT-shaped columns under reciprocating loading, the main conclusions are as\nfollows: The bearing capacity of steel reinforced concrete t-shaped cross\nsection column decreases with the increase of shear span ratio;\ndisplacement ductility decreases with the increase of axial compression\nratio; mechanical properties of the web load are superior to the ones of the\nflange load....
The main objective of this paper is to evaluate the seismic response of buildings of\ntypical reinforced concrete frames when concrete starts to deteriorate gradually and\nto make a comparison between the base shear and the displacement at different stages\nof earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames\nhave been designed for seismicity according to the recently adopted seismic code in\nAbu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to\nthese four buildings by using SAP 2000. Twenty-four models have been created (6\nmodels for each building) by decreasing the concrete strength gradually from 4000\npsi (281 kg/cm2) to 1500 psi (105 kg/cm2). This is to simulate the effect of harsh environment\non the strength of concrete in existing buildings....
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