This paper presents the findings of an experimental investigation undertaken to evaluate the influence of externally bonded CFRP laminates on the punching shear capacity of a two-way spanning slab-column connection. Two control and five strengthened RC slabs were prepared and tested under concentrated load. The variables of the experiment were the anchorage type and width of the CFRP plates used. The structural response of the samples in terms of load, deflection, strain and cracking was monitored and analysed throughout the experimental procedure. It was found that strengthening increases the ultimate load by up to 25% and reduces the maximum deflection by up to 50%. The strengthening increases the cracking load and significantly reduces the cumulative length of radial cracks. The samples strengthened with transverse anchorages exhibited significantly high level of residual strength. The experimental findings for unstrengthen cases are compared with several design codes.

In the present work, the structure and thermal properties of nanocomposites based on nanometal oxides (ZnO, Al2O3, ZrO2) and aromatic disulphochloride benzene compounds in a butadiene nitrile rubber (NBR) matrix that are obtained by gamma-rays processing have been investigated. Structural changes of nanocomposites depend on the type of used nanoparticles which have been identified by Fourier Transform Infrared (FTIR) spectroscopy and Electron Paramagnetic Resonance (EPR). Analysis by Scanning Electron Microscope (SEM) was used to study the morphology phase of the nanoparticles in the polymer matrix and the interface between the polymer-filler. In addition, the results of the samples based on NBR were obtained by thermogravimetric analysis (TGA)/differential thermal analysis (DTA). The results show that, the thermal stability of nanocomposites significantly decreased after irradiation, but with the addition of a certain amount of benzene-1,3-disulfonyl chloride (DSChB) and nanometal oxides to rubber blend the thermal stability could be improved.

This paper presents the effectiveness of strengthening slab-column connections against punching shear failure with near-surface mounted (NSM) carbon fibre-reinforced polymer (CFRP) bars.The experimental program consists of preparing and testing eight samples, two control and six strengthened samples. The main variables of the experiment are the strengthening layout and the cross-section area of CFRP bars. The results show that NSM strengthening increases the ultimate load by up to 44%. And the strengthening delays formation of the first crack in concrete thus maintaining a linear behaviour for load-displacement and load-strain curves for higher level of load. The NSM strengthening increases the flexural stiffness by over 100% and maintains a strong bond with concrete throughout the loading. The flexural strength of the slab increases, which subsequently improves the punching shear capacity. The experimental results are compared with several design codes by modification and implementation of Chen & Li's method. There is a good agreement between the calculated ultimate capacity of the strengthened samples and the obtained experimental results.

The chemical interaction of disulphochloride aromatic compounds with nitrile butadiene rubber (NBR) in the presence of combined nanosized powders of metal oxides (ZnO and Al2O3) was studied for the first time. Vulcanization of the prepared blends has been induced with two methods: by irradiation of gamma rays (D=300 kGy) and by pre-heating in the hydraulicpress and then subsequent irradiation (150 oC x 5', 300 kGy). In order to activate the crosslinking process, a combination of nano-oxides ZnO and Al2O3 were used. The surface of the nanocomposite was studied by using scanning electron microscopy. The mechanical properties of modified blends were studied and then compared with controlling sample (vulcanized with sulphur) and analyzed by the mechanical tests in aggressive environments after thermal aging. The study found that the use of 1,3-disulphochloride benzene with nano oxides produces cured materials with good resistance to aging and provides high service properties in air, seawater, and oil-bearing solution.

This paper investigates the behaviour of Concrete-Filled FRP Tubes (CFFT) as columns. The experimental programme consists of preparing and testing one steel column acting as control sample and three columns made with GFRP. The GFRP tubes were produced by filament winding method where the amount and orientation of the fibres was changed. The tubes had dimensions of 1000x100 mm (length x diameter) and were filled with C25/30 concrete. The columns were tested under compression and the load was applied at a pace rate of 0.5 mm/min. It was found that the GFRP tubes can efficiently confine the concrete and could be used as alternative material to steel tubes. The steel and GFRP samples developed a high level of strain throughout the testing. The GFRP sample with fibre orientation of 90° failed by FRP rupture, whereas the remaining samples failed by buckling. The orientation of the fibres at 90° was more efficient than orientation of fibres at 45° in terms of increasing the ultimate capacity. The GFRP samples displayed lower ultimate capacity compared to steel samples with same wall thickness, but increasing the wall thickness of the GFRP columns increased the ultimate load accordingly.