Papers by Keyword: Reinforced Concrete (RC)

Abstract: A finite element model of an existing reinforced concrete arch bridge was established. The reliability index was investigated based on the PDF module in ANSYS software. Taking the maximum concrete stress and tendon stress as limit state, the limit state functions of main arch, upright column and deck are established respectively. There are taken as series system to study the bridge system reliability according to the structural characteristics of reinforced concrete arch bridge. The lowest reliability index superstructure is selected as the whole structure reliability index. Based on JC method and made-up MATLAB program, the reliability index of the example bridge is calculated.

Abstract: A new kind of RC frame-shear wall structures with partial columns sliding at upper ends is proposed in this paper. A shaking table test of this new kind of structure model (Model B) and a conventional frame shear-wall structure Model (Model A) were carried out, and the plan layout and the member size of the two models are nearly identical. The two models are 3-story and 2-bay by 2-bay, and the second story of either structure is weak story. The test results showed that: (1) under the same intense earthquake, the damage of Model B is slighter than that of Model A; and (2) under the same intense earthquake, the interstory drift angle, the acceleration and the shear force of weak story of Model B are reduced remarkably in comparison to Model A.

Abstract: With the development of computer science and technology, computer hardware and software conditions have been improved greatly, which can make the finite element analysis of complex structure possible. Reinforced concrete is one of the most commonly used components in building structure, the study of reinforced concrete mechanics is mainly compared through the experiment, however finite element analysis of oblique section stress is not much, based on the theory of combining elastic-plastic mechanics, using ANSYS structure analysis software carries out the analysis of numerical simulation for the oblique section stress of reinforced concrete. Through the stress-strain numerical simulation curve, this paper can get the maximum load of oblique section without corrosion reinforced concrete frame that is0.03N/mm2, finally this paper will choose three different corrosion degree of the reinforced concrete members are to carry on the analysis of numerical simulation, and compared with experimental results, the results prove the reliability of numerical simulation, to provide a reliable basis for the mechanical study of reinforced concrete inclined section.

Abstract: In the last decade, the earthquakes in Turkey caused thousands of loss of life. The most unfortunate case was happened in 1999 Marmara earthquake and more than 20000 people lost their life. Recently an earthquake of magnitude 7.2 occurred in Van city and 600 dead toll was reported. Following the earthquake, the author was visited the earthquake region. In this study field reconnaissance survey the causes of failures observed on reinforced concrete (RC) structures were summarized. The main problem was the construction quality especially the concrete production process. The steel detailing was also a big problem for the region. The failed or damaged buildings were included several non-seismic details. The observed problems of damaged or collapsed buildings were short column formations, soft or weak stories, inadequate lateral confinements reinforcement, use of plain undeformed bars, poor material and concrete quality, lap spilice problems, strong beam-weak columns and weak beam-column joints.

Abstract: Turkish building stock is commonly composed of reinforced concrete moment resisting frames. Recent earthquakes in Turkey resulted thousands of failed or heavily damaged residential houses and office buildings. In addition of the earthquake failures, reinforced concrete structures may also failed only under their own weight. There are several examples such as Hicret Apartment in Diyarbakir (1983), Zumrut Apartment in Konya, in central Anatolia, Huzur Apartment in Istanbul (2007). On February 2nd, 2004 a 9-story reinforced concrete building in Konya (Zumrut Apartment) collapsed leaving 92 people dead. The first author of the paper was governmentally charged about the investigation of the failure causes. Carrot samples were taken from the concrete columns and steel samples were obtained from the disaster area. The dimensions of the structural members were determined. The structure was modeled in three dimensional space and vertical collapse analyses were conducted. The one of the main cause of failure was determined as the creep of the concrete occurred in excessively loaded columns. The main reasons of the damages and failures were determined to be the insufficiency in material quality, mistakes made in load selection and the inappropriate load-carrying dimensions. The construction mistakes and not obeying the design drawings are the other flaws. In this paper detailed information about the structure, creep analyses and vertical collapse analyze results were depicted in understandable format.

Abstract: Turkey is situated on a very earthquake zone of the world namely Alp-Himalayan Earthquake Zone. Several destructive earthquakes resulted in high dead losses in the last century. Turkish building stock consisted of nonductile RC framed structures commonly 3 to 7 stories. The common properties of the existing structures is the poor lateral resistance. The residental buildings with poor earthquake resistance must be rehabilitated with a rapid, economical, feasible and effective strengthening methods. The external shear wall addition to the existing poor frame is studied experimentally in this study. 6 specimens were tested under reversed cyclic lateral loading simulating the seismic action. The first specimen was the reference specimen and didn't contain any strengthening and tested to see reference behaviour. The other specimens were strengthened with external shear walls with or without openings. The size of the openings is a parameter in the study. Secons specimen didn't contain any opening. Columns of the frames also jacketed with reinforced concrete. The maximum lateral load carrying capacity, ductility capacities, energy consuption capacities, improvement in the lateral rigidities were investigated.

Abstract: The idea of strengthening the existing masonry infill walls of reinforced concrete (RC) frames has attracted many research groups in the last decade. The use of carbon fiber reinforced polymer (CFRP) strips along the diagonals of infills has become one major technique applied for this purpose. An experimental study conducted by the authors focused on the effect of aspect (height/width) ratio of hollow clay tile infills on the overall response attained by this strengthening methodology. Two different aspect ratios (HCT) were selected in the experimental study. However, a wider range of aspect ratios should also be investigated for design purposes. Therefore, a numerical model of the test frames are developed, which are validated by the experimental response curves. The basics of the numerical model that leads to a parametric study is the subject of this article.

Abstract: The aim of this study was to obtain special cathodic protection (CP) behavior in coastal bridge structures. This bridge structure was located to the area where repetition between fresh water and sea water taken place due to ebb and flood tide. In this study, zinc-mesh anode was used as a sacrificial anode. Thus, it was a good opportunity to verify the effectiveness of sacrificial anode CP (SACP) in this special location. Measurement was conducted for three years. Test Factors were corrosion potential, CP potential, 4 hour depolarization potential, and CP current. Moreover, resistivity and corrosion rate were measured by the multi-functional corrosion monitoring sensor (DMS-100, Conclinic Co. Ltd) that could measure potential, galvanic current, corrosion rate, concrete resistivity, and temperature. After three years from installation of CP, it could confirm that although some pier showed low depolarization potential less than 100mV, most piers showed good protection both electrochemical and physical aspects.

Abstract: Electricity accelerated corrosion is a common method to obtain corroded reinforced concrete specimens in current experimental research, and it has some relevance and differences with natural corrosion. The paper undertakes a detailed comparative research on the relevance and differences of the two corrosion conditions from the corrosion mechanism, the corrosion process, the corrosion rate, the electric flux and corrosion features, and this provide a better understanding of the research achievements based on accelerated corrosion.

Abstract: The focus of this study is on the differences in quantity estimates made by BIM and a senior engineer using conventional method for materials needed during construction. BIM-Revit Architecture 2012 is utilized to establish the information for two actual cases the control room for a new construction and a single floor on a school campus to conduct estimates for the amount of reinforced concrete needed. For comparison, an engineer with considerable experience is also asked to perform the above estimate. Data from the two estimates are compared and the unit price obtained from the Public Construction Commission is applied to calculate the price difference. The result shows that in Case 1, the engineers estimate is higher than that of BIM by 1.33%, while in Case 2, the engineers estimate is higher than that of BIM by 0.30%. The results indicate that estimates made by BIM have high accuracy. Thus, applying BIM toward the construction industry may effectively reduce human errors such as omissions and miscalculations.