This paper presents the progress of the research on making Geopolymer concrete using the Thermal Power Plant fly ash, (Ukai) Gujarat, India. The project aims at making and studying the different properties of Geopolymer concrete using this fly ash and the other ingredients locally available in Gujarat. Potassium Hydroxide and sodium Hydroxide solution were used as alkali activators in different mix proportions. The actual compressive strength of the concrete depends on various parameters such as the ratio of the activator solution to fly ash, morality of the alkaline solution, ratio of the activator chemicals, curing temperature etc. In recent years, Concrete usage around the world is second only to water. Ordinary Portland cement (OPC) is conventionally used as the primary binder to produce concrete. The amount of the carbon dioxide released during the manufacture of OPC due to the calcinations of limestone and combustion of fossil fuel is in the order of one ton for every ton of OPC produced. In addition, the extent of energy required to produce OPC is only next to steel and aluminum. Attempts to reduce the use of Portland cement in concrete are receiving much attention due to environment-related. Fly ash-based Geopolymer concrete is a 'new' material that does not need the presence of Portland cement as a binder. The role of Portland cement is replaced by low calcium fly ash. Geopolymer is an inorganic alumino Hydroxide polymer synthesized from predominantly silicon (Si) and aluminum (AI) materials of geological origin or byproduct materials such as fly ash. The term Geopolymer was introduced to represent the mineral polymers resulting from geochemistry. The process involves a chemical reaction under highly alkaline conditions on Si-AI minerals, yielding polymeric Si-O-AI-O bonds in amorphous form.

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This paper reports hardness testing conducted on welded butt joints by FSW and TIG welding process on similar and dissimilar aluminium alloys. FSW joints were produced for similar alloys of AA7075T651 and dissimilar alloys of AA7075T651-AA6061T6. The Friction stir welds of AA7075 & AA6061 aluminium alloy were produced at different tool rotational speeds of 650,700, 800, 900, 1000 and transverse speed of 30, 35, 40 mm/min. TIG welding was conducted along the rolling direction of similar and dissimilar aluminium plates. The Brinell hardness testing techniques were employed to conduct the tests; these tests were conducted on the welds to ascertain the joint integrity before characterization to have an idea of the quality of the welds

The article presents hygrothermally induced buckling of geometrically linear laminated composite plates resting on two parameters Pasternak elastic foundation subjected to moisture and temperature-independent and -dependent material properties with random system properties. System properties such as elastic moduli, shear moduli of the constituent materials, hygroscopic contraction coefficients, thermal expansion coefficients, and foundation stiffness parameters are modeled as independent basic random variables. A computationally efficient C 0 finite element method combined with Taylor series based mean-centered first-order perturbation technique via higher order shear deformation plate theory is used to solve the random eigenvalue problem. Typical numerical results for dimensional mean and coefficient of variance of hygrothermally induced buckling load of laminated composite plate subjected to uniform hygrothermal loadings are examined with uniform moisture concentration and temperature rise, plate thickness and aspect ratios, total number of plies, fiber orientations, elastic foundations, and different boundary conditions with random system properties. The numerical results obtained by the present solution approach are validated with those available in the literatures and independent Monte Carlo simulation.

Motivated by the sustainable production perspective, a laboratory testing program is exercised to ascertain the feasibility of utilizing copper slag in place of the natural fine aggregate in concrete. Totally, fifteen concrete mixtures were prepared to incorporate copper slag in place of the fine aggregate in concrete. e attributes of concrete specimens made with varying proportions of copper slag were compared (ranging from 0% to 100% substitution) at a w/c ratio of 0.44, and the optimum percentage of copper slag was decided. e w/c ratio in the mix containing optimum copper slag percentage was then varied (from 0.42 to 0.36) to examine the influence of the change in the quantity of available water on the strength attributes of concrete. Concrete specimens were assessed for workability, density, compressive strength, flexural strength, and split tensile strength. SEM images and X-ray diffractograms of concrete specimens were also studied. e results obtained indicated a significant increase in workability and a small rise in the bulk density of concrete. e study concludes that substituting 60% sand with copper slag results in better compressive strength compared to control concrete and can be improved further by reducing the w/c ratio in the mix.