In this study, a model for predicting the ultimate strength of rectangular concrete filled steel tube (RCFST) beam-columns under eccentric axial loads has been developed using artificial neural networks (ANN). The available experimental results for (111) specimens obtained from open literature were used to build the proposed model. The predicted strengths obtained from the proposed ANN model were compared with the experimental values and with unfactored design strengths predicted using the design procedure specified in the AISC and Eurocode 4 for RCFST beam-columns. Results showed that the predicted values by the proposed ANN model were very close to the experimental values and were more accurate than the AISC and Eurocode 4 values. As a result, ANN provided an efficient alternative method in predicting the ultimate strength of RCFST beam-columns.

This study adopted the investigation of the effect of a material that can be used as an alternative to steel reinforcement of shear in reinforced concrete beams, as the most susceptible to corrosion to which reduces the time service of the concrete structures and increase the maintenance costs is the steel reinforcement of shear for the closeness of surface of concrete. Therefor non-corroding material is needful for concrete structures and PVC fiber reinforcement is chosen. Experimentally nine reinforced concrete beams have been tested to determine the effect of PVC fiber reinforcement on the concrete beam resistance load, the load of cracks, deflection achieved and distribution with dimension of cracks. Three volume fraction ratios were taken for PVC fiber reinforcement (0, 0.25 and 0.5), which were identical to the shear reinforcement used in this research (0,0.29 and 0.54). All the concrete beams were tested with in on one program by applied a center load from the top in the middle to the failure load and the results were impressive. The specimens containing the PVC fiber reinforcement percentages achieved a remarkable increase in the crack and ultimate load of the concrete beams before and after cracks with direct effect in changing the failure type. While the deflection achieved due to the increase in PVC fiber percentage is more than the allowable deflection in the ACI Code equations of the reinforced concrete beams and more of these if the use of PVC fiber and steel reinforcement of shear together. A smaller measurement of the maximum cracks width was achieved by using advanced percentages of PVC fiber and shear reinforcement (0.5 and 0.54) respectively.

The aim of this review paper is to summarize available reports, papers, theses, dissertations and conference papers dealing with the performance of aluminum-concrete composite columns. Hollow aluminum sections filled with concrete have been used as composite columns due to their corrosion resistance, easy production, appearance and lightweight. Many researches were performed in the area of concrete-filled hollow sections (tubes). However, there are few researches have been performed on concrete-filled aluminum tubes. In this review, different available published papers are summarized to view the type of the studied aluminum-concrete columns and the main studied parameters that affecting the behavior of these composite columns. More than (190) specimens are collected and showed in this review.

In this study, a model for predicting the ultimate strength of circular concrete filled steel tubular columns (CCFST) under axial loads has been developed using fuzzy inference system (FIS). The available experimental results for (129) specimens obtained from open literature were used to build the proposed model. The predicted strengths obtained from the proposed FIS model were compared with the experimental values and with unfactored design strengths predicted using the design procedure specified in the AISC 2005 and Eurocode 4 for CCFST columns. Results showed that the predicted values by the proposed FIS model were very close to the experimental values and were more accurate than the AISC 2005 and Eurocode 4 values. As a result, FIS provided an efficient alternative method in predicting the ultimate strength of CCFST columns.

This work deals with an experimental and computational study was carried out on the structural behavior of circular concrete filled aluminum tubular columns subjected to increasing axial load. Twenty four specimens were tested to investigate the effect of diameter, D/t ratio and slenderness ratio of a aluminum tube on the load carrying capacity of the concrete filled tubular columns. Diameter to wall thickness ratio between 23.3 ≤ D/t ≤ 47.8, and the length to tube diameter ratio of 3 ≤ L/D ≤ 10 was investigated. The structural performance of the concrete-filled aluminum tube columns (CFTa) was investigated using constant concrete cylinder strengths of 24.2 MPa.The main purpose of the computational study aimed to investigate the potential of using fuzzy inference system (FIS) to predict the strength of the composite columns. Fuzzy inference system (FIS) model has been provided to be very effective in predicting the ultimate strength of aluminum-concrete composite columns. The average values of ratios of experimental to predicted ultimate loads are 1.001 forthe Sugeno FIS model. The circular hollow section tubes were fabricated by extrusion using 6061-T6 heat-treated aluminum alloy