Contribution/ OriginalityThis study is one of very few studies, which have investigated into the effective methods and appropriate tools to carry out the demolition of existing structures so that the debris can be put into the reuse or recycling operations, getting useful products and also save Mother Earth from unsustainable degradation.

Colossal materials do not provide a wide range of applications due to their mechanical property limitations. Fiber reinforced polymer composites are now considered as an important class of engineering materials. The processing and mechanical characterization of a new class of multi-phase composites consisting of polyester resin reinforced with jute-glass-silk fiber. This research investigation deals with mechanical properties of hybrid polymer composite. Woven palm fiber, teak wood dust and SiC Nano particles have been used for fabrication of the composites. Experiments have been planned as per Response Surface Method. After preparing the composite material by hand layup technique and then the mechanical characterizations are performed. Multi-response optimization has been carried out using Multi objective optimization on the basis of the ratio analysis method (MOORA) and Whale Optimization Algorithm. Optimal results have been verified through confirmatory experiments. Based on the experimental observations density, flexural and Ultimate Tensile Strength, it is concluded that teak wood powder influences the mechanical properties more than that of other two reinforcements but Nano particle filled composites shows better properties.

Since last few years, marble has been deliberated as some of the utmost significant embellished constructing resources. Marble Powder (MP) and Fly Ash (FA) are nearly those materials, which creates health hazards and pollutes the environment. This present study targets to investigate the effect of marble powder and fly ash as fractional replacement of cement respectively in different concrete mixes. The M30 grade of concrete was chosen with a continual w/c ratio 0.43 where fractional replacement of Portland Pozzolana Cement with Marble Powder and Fly Ash is done in different proportion. After preparing the samples according to Taguchi’s method orthogonal array, the mechanical characterizations are performed. Hardened concrete tests such as compressive strength, split tensile strength and flexural strength test have been piloted to appraise the mechanical properties of concrete. Two current multi-response optimization techniques were used i.e. Combinative Distance-based Assessment (CODAS) and Combined Compromise Solution (CoCoSo) method for optimization of process parameters. In order to outline comparative consequence of measured criteria a pairwise comparison matrix was used. The results of all tests were analyzed, comparison has done among concrete mixes and the conclusion is drawn.

Railways form the backbone of all economies, transporting goods, and passengers alike. Sleepers play a pivotal role in track performance and safety in rail transport. Composite sleeper is becoming a suitable alternative for replacing the existing concrete, steel and particularly timber sleeper in both mainline and heavy haul rail network. Composite sleeper technologies are already available but they have gained limited acceptance by the railway industry. A number of composite railway sleeper technologies have been developed but their applications in rail tracks are still limited. This paper discusses in brief about the materials that have been used in making sleepers in the early stages of railways and rigorously reviews the recent developments on composite sleepers and identifies the critical barriers to their widespread acceptance and applications. It has been shown that majority of the sleepers do not last till their expected design life resulting in massive replacement and repair cost. Currently the composite sleeper technologies that are available ranges from sleepers made with recycle materials starting from plastic, rubber, construction waste etc. While these recycled material based sleepers are low cost, the major challenges of using this type of sleepers are their limited strength, stiffness and dynamic properties which in most cases, are incompatible with those of traditional concrete, steel or timber sleeper. This paper rigorously reviews the recent developments on composite sleepers and identifies the critical barriers to their widespread acceptance and applications.