lkali activated (Geopolymer) concrete is an excellent and viable alternative to Portland cement based concrete as it can be produced using industrial by-products such as Ground Granulated Blast Furnace Slag (GGBS) and fly ash (source of reactive alumino-silicates) along with less energy craving ingredients such as alkali activators. In this study, slag based geopolymeric concrete mixes of M40 and M80 grade were prepared using GGBS and fly ash in proportion of 70:30 by weight. Geopolymeric binder was activated using combination of Sodium hydroxide and Sodium Silicate. Activator modulus (i.e. SiO2 / Na2O) was maintained as 1 and Na2O was kept as 7% and 8% by weight of total binder respectively for M40 and M80 grade geopolymeric concrete mixes. Both the concrete mixes were evaluated for fresh properties of concrete (slump and air content) along with mechanical properties of hardened concrete. Performance of geopolymeric mixes was compared with two conventional concrete mixes of equivalent grade (i.e. M40 and M80) in terms of aforementioned mechanical properties. Study concludes that slag based geopolymer concrete mixes of a particular strength were developed at significantly lower total binder content in comparison to cementitious binder required for development of conventional Portland cement based concrete of equivalent strength. Early age compressive strength of normal strength geopolymeric concrete mixes is higher in comparison to conventional concrete mix. Modulus of elasticity and Poisson’s ratio of geopolymeric mixes of both normal and high grade are observed to be lower in comparison to their corresponding conventional concrete mixes of equivalent strength.

Replacing or servicing corroded reinforced concrete structures requires careful consideration of the rate of corrosion of the embedded rebar. Corrosion rates are usually measured using monitoring techniques, but these techniques may not always give reliable results due to the effect of factors called rate influencers. Though the consideration of rate influencers does not entirely alleviate the problem, monitoring them during measurements will significantly reduce the probable error. Hence, this paper compares the experimental results of prior studies with an effort to draw out the best corrosive environment for the efficient working of a few widely used monitoring techniques and presents a list of some major rate influencers that need concern for the accurate evaluation of corrosion. A literature review is performed to achieve the above objectives. The Monitoring techniques considered in this study are linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), galvanostatic pulse technique (GPT), and half-cell potential (HCP).

Synthetic plastics are widely used, mostly in packaging industries and also in forms of disposable utensils. But, this also influences in increasing waste and polluting the environment rapidly. To deal with this, the use of biodegradable plastic is growing a lot faster than before. This work summarizes the role of food waste and their starch in producing biodegradable plastics and witnessed the making of biodegradable plastic from different types of food waste. This material will majorly help in reducing food waste and also in controlling plastic waste. Also, this paper covers the basic details on the cost for commercialization required for making this material available for use publicly. Some biodegradable plastics which are already available for commercialization are starch based, lignin based, bacteria based, cellulose based and fibre reinforced plastics. Our review is based on the starch based bioplastic from potato peels, cellulose based from banana peels, lignin based from pumpkin waste.

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Many researchers across the globe have carried out fire safety risk analysis to gather evidence and pertinent data for different Reinforced Cement Concrete (RCC) members exposed to fire. Assessment of fire-damaged structures furnishes the minute details of the effect of fire on the properties of concrete.The study indicates the condition assessment of the turbo-generator (TG) unit, comprises of concrete bearing pedestals, deck and supporting columns. The research was conducted using Non-Destructive Testing (NDT) techniques using Rebound hammer test, Ultrasonic Pulse Velocity (UPV) test, Concrete Cover measurement, Carbonation and Crack depth measurements followed by microstructural studies using an X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Optical Microscope (OM), and Mercury Intrusion Porosimetry (MIP). The samples were taken from a fire-damaged concrete bearing pedestal B2 and a non-fire-damaged concrete bearing pedestal B4 of the TG unit. The approach enabled us to find the extent of damage to the RCC members exposed to fire. The above mentioned test witnessed that the concrete bearing pedestal B2 was the moderately distressed member, expressed doubtful quality of concrete, higher porosity, reduced residual compressive strength and reduction in yield strength of steel. However minor distress in form of crushing at the top grout portion was observed in concrete bearing pedestal B4, and no apparent distress was observed in supporting columns of TG unit. Based on the distress identified, repair and remedial measures were proposed to concrete bearing pedestals in order to improve the performance of the TG unit.