The response of concrete with waste materials under impact loading are explored through detailed literature review. The effect of percentage of waste incorporation, size of waste aggregate, volume fraction of fibre and size of fibre is reviewed in terms of energy absorption, failure mode, dynamic compression and tension under three commonly used impact tests. Based on the survey, the benefits and significance of waste materials on incorporation of concrete is presented. The better performance was observed for the use of hybrid fibres over individual fibres even at high volume additions. It was suggested for potential usage of eco-friendly concrete using recycled coarse aggregate and rubber particles for roadways, walkways, highway barriers and protective structures against impact loading. The rubber particles up to 15% for coarse aggregate replacement in concrete have been recommended under low velocity impact loading. The coir fibres have absorbed highest impact energy with maximum value for 2% fibre volume and 40 mm fibre length and it has highest residual impact strength ratio among other natural fibres. The suggested future areas of research of waste materials on concrete under dynamic loading are rice husk ash, sugarcane bagasse ash, waste foundry sand, sugarcane and nylon fibres.

The response behaviour of identical adjoining structures interconnected by Maxwell dampers subjected to seismic excitations is studied. To estimate the efficacy of Maxwell damper, the adjoining structures interconnected by Maxwell dampers having same damping and also different damping coefficient is analysed. The optimal damper parameters are estimated for utmost response mitigation. The outcomes of the study indicate that earthquake induced response of adjoining structures interconnected by Maxwell dampers with appropriate parameters reduce effectively. Further, lesser dampers of appropriate parameter and at suitable locations can substantially mitigate the response of interconnected structures under real ground motion excitations.

The present research presents both detailed and simplified formulae on the octagonal concrete-filled steel tube (CFST) columns to define the ultimate strength of this type of column. These formulae have been validated and proved to be accurate through comparisons with experimental tests and with other available methods proposed by other researchers. On the other hand, employing the new formula in the constitutive model of core concrete in the finite element analysis (FEA) has shown to be of adequate accuracy to predict the behaviour of octagonal CFST columns. The effects of variation in both concrete-steel strength ratio (f′c/fy) and depth-to-thickness of the tube (D/t) were studied. It is found that by decreasing the depth-to-thickness ratio of steel tube (D/t) the confining pressure will be increased. Also, decreasing the ratio of compressive strength of concrete to yield strength of steel (f′c/fy) the confining pressure will be decreased.

In this paper, a novel steel-concrete composite structure namely partially filled steel box-concrete (PFSBC) is proposed for structures which are mainly subject to eccentrically loaded compressive force. The cross-section of this kind of structure is a hollow steel box, which is divided into two parts, with one of them filled with concrete. The static behaviour of PFSBC structures was studied by nonlinear finite element method (FEM) and laboratory tests. The nonlinear FEM analysis is focused on the parametric study of its bearing capacity under the action of eccentric load. It can be found from the study that concrete filling ratio (CFR) which is defined as the ratio of filled concrete area to the whole area of the steel box, and the slenderness of the member, besides the confinement coefficient, are the most important parameters that influence the bearing capacity of PFSBC. To calibrate the FEM results, two PFSBC specimens with different slenderness ratios were tested in the laboratory under the action of eccentric load, and the load-displacement curves were measured. The test results coincided highly with the FEM calculated bearing capacity and other mechanical responses, which indicates the correctness and accuracy of FEM calculation.

The present study aims to evaluate the effectiveness of externally bonded stainless steel wire mesh (SSWM) in enhancing the shear strength of reinforced concrete (RC) flanged beams with T-shape cross-section. To identify appropriate SSWM as a strengthening material, tension test and bond test are performed on five locally available SSWM. An experimental investigation is conducted to study the behaviour of RC T-beams strengthened by externally bonded 40 × 32 type SSWM under transverse loading. Two beams are considered as control specimen, and four beams are externally strengthened by two different wrapping configurations. All beams are tested under the two-point loading until failure. Results of experimental investigation, in terms of cracking load, ultimate load, deflection, prove the effectiveness of SSWM in shear strengthening of beams. The numerical model of controlled and SSWM strengthened T-beam specimen is also developed using finite element based software ABAQUS to validate experimental results.