Department of Civil Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

Sugarcane bagasse pyrolysis is an effective way of producing renewable and sustainable energy. A combined study on characterisation of primary and secondary by-products of sugarcane towards the effective use of bagasse as an energy feedstock and biochar is not yet available in the existing literature. This study is an attempt to bridge this gap and to understand the complete valorisation potential of sugarcane bagasse and its by-products. In this study, the elemental, structural and compositional analyses of sugarcane bagasse collected from various sources were carried out and their thermal decomposition behaviour under pyrolysis conditions was investigated using thermogravimetric data. The composition of all sugarcane bagasse samples showed remarkable similarity, except for the presence of high soluble sugars in two of the six samples. The hemicellulose content in the lignocellulosic bagasse samples was found to have a distinct thermal decomposition pattern, resulting in deconvolved derivative thermogravimetric curves with peaks centred at around 300 °C. A detailed analysis of the thermogravimetric data indicated a complex multi-step thermal degradation behaviour for bagasse under pyrolysis conditions. The pyrolysis reaction kinetics of sugarcane bagasse were developed by using iso-conversional and model-fitting methods. Further, SEM–EDS analysis revealed that the biochar obtained from bagasse fast pyrolysis experiments was predominantly siliceous. X-ray diffraction studies on biochar indicated that there were no crystalline phases, even at pyrolysis temperature of 700 °C. © 2020, Society for Sugar Research & Promotion.

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Sugar Tech

Thermochemical Conversion of Sugarcane Bagasse: Composition, Reaction Kinetics and Characterisation of By-Products

Pretreatment processes on rice husk ash (RHA) influence its properties and in turn, the performance of concrete. However, most of the available literature captures only the influence of the RHA usage in concrete without focusing on the systematic pretreatment process and optimization of RHA dosage on physical and chemical perspective. Further, the replacements were done on weight basis, leading to higher binder volume and inaccuracies in the performance evaluation. The main objective of the present study is to adopt adequate pretreatment process and to systematically optimize the RHA dosage (vol. %) towards better strength and durability properties. Hence, the current study focuses on understanding the nature of RHA through characterization, followed by suitable pretreatment processes for enhancing the properties of RHA. The enhancement in the chemical activity of the treated RHA was assessed through pozzolanic activity tests (strength activity index, lime consumption test and soluble silica). Based on the physical properties (particle size, surface area and packing density), chemical characteristics (strength activity index) and the energy required, the grinding time (30 min) was optimized rationally. The optimized dosage of RHA (20% by vol.) was evaluated for its performance through fresh, mechanical and durability properties. From the results, it is evident that adequate pretreatment, along with systematically optimized RHA dosage yields enhanced performance in concrete properties. © 2020 fib. International Federation for Structural Concrete

Structural Concrete

Suitable pretreatment process for rice husk ash towards dosage optimization and its effect on properties of cementitious mortar

Alkali-activated binders are sustainable alternatives to carbon-intensive conventional cements. A comprehensive review of the potential of different agro-waste ashes and their performance as precursors in alkali-activated binders are essential to enable their acceptance in the construction sector. Hence, the present study focusses on a systematic review of the alkali-activation of bagasse ash, rice husk ash, corn cob ash, palm oil fuel ash, wheat straw ash and sugarcane straw ash. Moreover, their influence on the mechanical and durability characteristics of alkali-activated concrete is also presented. Based on the review, it is found that except for rice husk ash, all the other agro-waste ashes have almost similar silica content as that of fly ash. The morphologies of the different agro-waste ashes are found to be distinct. Incorporation of agro-waste ashes in fly ash-based binders results in better resistance to acid attack than slag-based binders. Addition of agro-waste ashes brought down the drying shrinkage of slag-based binders significantly. Ambient curing is beneficial for bagasse ash-based alkali-activated mortar specimens. Water absorption is higher for agro-waste ash based alkali-activated binder specimens due to the porous cellular structure of agro-waste ashes. Enhanced performance at elevated temperatures is observed for agro-waste ash based alkali-activated binders. Rice husk ash-based binders are remarkably stable at elevated temperatures. © 2020 Elsevier Ltd

Journal of Cleaner Production

Agro-waste ash based alkali-activated binder: Cleaner production of zero cement concrete for construction

This paper proposes an innovative coupled wall system, named the tuned viscous mass damper (TVMD) coupled wall system, for use in high-rise buildings. This novel wall system is expected to control both the lateral inter-story drifts and the floor accelerations of high-rise buildings when subjected to strong ground motions, thus enhancing their seismic resilience. The TVMD consists of a component that provides stiffness connected in series with a ball screw device that can provide large inertial and damping forces, even when subjected to small deformations. In this system, TVMDs are arranged to connect adjacent wall piers in a zig-zag configuration. Such a strategic TVMD arrangement makes efficient use of the vertical relative displacements of the adjacent walls induced by their flexural deformation to generate the motions and forces of the TVMDs. Two methods are presented for the optimal design of this system, namely, a single-mode tuning method and a multi-mode tuning method. Dynamic response analysis is conducted on a representative 15-story TVMD coupled wall system. The results of the analysis indicate that the TVMDs designed by the single-mode tuning method not only suppress the dynamic responses of the tuning mode, but also provide additional damping for the lower-order modes of the primary structure. The multi-mode tuning method shows similar performance to the single-mode tuning method if the latter is used to tune the higher-order mode. Finally, real-time hybrid simulations were conducted to examine the seismic performance of the proposed system. The test results demonstrate the advantages of the TVMD coupled wall system and indicate that the detuning effect is slight for this system, even when subjected to strong ground motions.

Engineering Structures

Tuned viscous mass damper (TVMD) coupled wall system for enhancing seismic performance of high-rise buildings

This work presents the use of osmotic microbial fuel cell (OsMFC), for the first time, to concentrate nutrients and recover water and energy from source separated urine. Four sets of concentration of fresh urine as feed and NaCl as draw were examined: 10% fresh urine vs 0.25 M NaCl; 10% fresh urine vs 2 M NaCl; fresh urine vs 0.25 M NaCl; and fresh urine vs 2 M NaCl. A maximum water flux of 14.27 LMH was attained when 10% of fresh urine and 2 M of NaCl were used as feed and draw solutions, respectively. Additionally, OsMFC concentrates ~99% of TOC, TN, NH4+, and 100% of PO43− and NO3− from urine at the feed side. Polarization studies indicate that the power generation in OsMFC is related to the rate of change of conductivity and the initial conductivity of the anolyte. The maximum (0.12187 W m−3) and minimum power densities (5.3372 × 10−4 W m−3) were obtained for the conditions of fresh urine vs 0.25 M NaCl and 10% fresh urine vs 0.25 M NaCl, respectively. The study shows that OsMFC is an effective pretreatment process to concentrate nutrients from urine by recovering water and energy, simultaneously. © Elsevier Ltd

Chemosphere

Concentrating nutrients and recovering water and energy from source separated urine using osmotic microbial fuel cell

Calibration is an essential step that is involved in the application of process based distributed hydrological models. The calibration process focuses on improving the performance index values rather than improving the process dynamics. The poor process dynamics in the model reduces its predictive power. The current study proposes a modified calibration approach (MCA) for the Soil and Water Assessment Tool (SWAT) model, which helps to improve the process dynamics in model through constraining the parameters. The modified calibration method uses the association between physically interpretable SWAT model parameters as soft data for calibration. The proposed calibration approach is validated in the Little River Experimental Watershed, USA. The results indicate that the proposed calibration method improves the process representation and spatial prediction in the calibrated model compared to the standard calibration procedure based on streamflow data. © 2021 Elsevier Ltd

Environmental Modelling and Software

Calibration of hydrological models considering process interdependence: A case study of SWAT model

AGU Fall Meeting

A Process Driven Downscaling Technique to Improve Confidence in Climate Projections

The production of cement is a carbon dioxide-intensive process. Replacing ordinary Portland cement (OPC) with industrial by-products can bring down the carbon footprint associated with cement production. Various industrial residues are currently used as alternative cementitious materials in this regard. However, developing a low carbon dioxide composite cement with different pozzolans alters the packing density, which influences its properties. Although studies have been conducted on the use of fly ash and slag at lower cement replacement levels, studies on the packing density and strength of ternary and quaternary composite cements with higher replacement levels are limited. In this study, fly ash, blast-furnace slag, ultra-fine fly ash and ultra-fine slag are used as a partial replacement for cement in various proportions. Out of the 51 mixtures tested in the study, 11 combinations were selected, based on the maximum packing density, for further investigations on fresh and hardened properties to arrive at the best trade-off between cement reduction and desired properties. The early-Age strength is influenced by the packing density of composite cements, whereas the later-Age strength is found to be highly governed by the amount of OPC and the pozzolanic potential of the industrial by-products. © 2022 ICE Publishing: All rights reserved.

Proceedings of the Institution of Civil Engineers: Engineering Sustainability

Composite cements: Synergistic effects of particle packing and pozzolanicity

Use of blended cement with industrial by-products as supplementary cementitious materials is a sustainable alternative to carbon-intensive conventional cements. Although the potential of several new alternative cementitious materials has been reported in the literature, their industrial acceptance is minimal compared to fly ash and slag. In addition to performance evaluation in concrete, it is essential to compare the performance of new alternative cementitious materials with other widely recognised materials in industries to facilitate their acceptance. Therefore, the present study focuses on a thorough review of the characteristics and performance of bagasse ash in concrete compared to fly ash and slag blended concrete. Moreover, fresh, hardened and durability characteristics of bagasse ash blended concrete are critically reviewed. Based on a comprehensive review, the optimum replacement levels for bagasse ash, fly ash and slag are found to be 20%, 30% and 50% respectively. Even though adverse effects such as delayed initial set, workability reduction and increased consistency were observed for bagasse ash blended cements, the strength gain of bagasse ash blended concrete is found to be better than fly ash/slag blended concrete. Significant enhancement in resistance against chloride and water permeability is also reported for bagasse ash blended concrete compared to fly ash and slag blended concrete. © 2020 Elsevier Ltd

Comparison of sugarcane bagasse ash with fly ash and slag: An approach towards industrial acceptance of sugar industry waste in cleaner production of cement

This study aims to enhance the accuracy and reliability of the Global Ensemble Forecast System's (GEFS) precipitation forecasts over the Indian subcontinent using two post-processing techniques, namely the Analog method (AN) and Logistic Regression method (LR). The post-processing techniques and GEFS Numerical Weather Prediction Model (NWP) outputs were evaluated against the observed dataset using probabilistic and deterministic evaluation metrics. Results found that both the methods considerably improves short range to medium range (1-15 day) precipitation forecasts over India. Overall results showed that both the methods perform poorly during the monsoon seasons compared to other seasons. Basin analysis showed that both the methods underperform in the Western Ghats, while the performance is comparable and decent in other parts of India. Analysis of precipitation at different terciles showed that both the AN and LR methods underperforms at higher terciles compared to the lower ones. This is because the GEFS model itself was performing poorly in detecting the heavy precipitation events. The comparison of logistic regression and analog methods shows that the LR method outperforms the AN method in almost all the locations and lead times.