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

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Analysis and Design of Plated Structures

Behavior, analysis and design of light gauge steel members

Indian Geotechnical Journal

Performance of Lateritic Soil Slopes at the Onset of Rainfall Infiltration

Steel fibre reinforced concrete (SFRC) is widely recommended where fatigue is a predominant mode of failure, such as concrete bridges, offshore structures and concrete pavements. From a detailed literature review, it was observed that the different fibre parameters like fibre type, fibre volume, aspect ratio, etc., influence the crack resistance performance and thus, the fatigue endurance limit. This paper attempts to understand the effect of various test parameters (stress ratio, frequency) and fibre parameters (length, diameter, volume of fibres, aspect ratio and reinforcing index) on the fatigue life of SFRC based on available literature data. Studies involving SFRC with volume fractions of 0.13–2.0% are included in the analysis. The objective of the current study is to propose a generalized fatigue model, based on statistical analysis of data available from literature, for pre-cracked SFRC with the consideration of the above variables. A multiple linear regression (MLR) analysis using SPSS software was used to perform analysis of variance (ANOVA). The most significant parameters, obtained from the analysis, for the prediction of fatigue life of pre-cracked SFRC are stress ratio, length of fibre and reinforcing index. The generalized expression can be used for the prediction of the post cracking fatigue life of SFRC for volume fractions within the range of 0.13–2.0%. It is envisaged that these generalized models could be integrated into any SFRC design methodology requiring fatigue response prediction, leading to better-optimized designs. Overall, this study expands the state-of-the-art on fatigue behaviour of SFRC and its analysis.

Environmental Sciences and Sustainable Engineering Centre (ESSENCE)

RILEM Bookseries

Statistical Modelling of Flexural Fatigue Response of Steel Fibre Reinforced Concrete

Landslides and debris flow possess greater damaging power due to their sudden occurrence and relatively high velocity. Landslide flow behaviour can be interpreted using a granular column collapse model. In the present study, dry granular flow behaviour on the erodible and non-erodible layers is analysed. A granular column collapse model with its spreading surface containing an erodible and non-erodible layer is used in this study. The unique property of granular particles to behave in a heterogeneous manner requires its analysis to be done individually. Therefore, particulate-level simulations are performed with the help of the discrete element method (DEM). Particle trajectories and the interaction forces between the particles in the system are studied at every step. Notable changes are found in the flow behaviour with respect to different aspect ratios. Parameters like bulk coordination number and the evolution of energy of the system are taken into consideration in this study. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Lecture Notes in Civil Engineering

Study of Dry Granular Flow Behaviour with and Without Erodible Layer

The resultant lateral pressure exerted by the backfill soil and its point of application on any earth retaining structure are governed by the mode of wall movement and the soil arching effect. The nonlinear active pressure distribution due to the arching effect under different mode of wall yielding for retaining wall with horizontal backfill has been addressed in the past. In this letter, a new analytical approach for the active earth pressure incorporating arching effect behind a rigid wall with sloping cohesionless backfill subjected to rotation about the base is proposed. The slip surface developed in the backfill is assumed to have logarithmic spiral geometry. Using the proposed formulation, the influence of slope angle, angle of internal friction, and wall friction on the active thrust and its point of action has been investigated. © 2021, Springer Nature Switzerland AG.

Innovative Infrastructure Solutions

Active earth pressure on retaining walls with sloping backfill considering arching effect under rotation about base

Handbook of Algal Biofuels

Photosynthetic microalgal microbial fuel cells and its future upscaling aspects

A novel and simple stochastic meshfree method is proposed in the present study for the stochastic eigenvalue analysis of problems in structural mechanics. Young's modulus is modelled as homogeneous random field. Both truncated normal and lognormal distribution characteristics are used. The current work proposes to use Monte Carlo simulation (MCS) on a modified system of equations. Here, the stochastic stiffness matrix is approximated using Taylor series expansion as in perturbation methods. However, the method does not make any approximations for eigensolutions, which are also unknown functions of random variables. This enables the numerical integration of stiffness matrix and its derivatives outside the simulation loop. Unlike the direct MCS on system of equations, this simple but previously unexplored modification proposed, can result in accurate and more efficient evaluation of stochastic eigensolutions. A few numerical examples are solved using the proposed method; buckling of columns, buckling of thin plates and free vibration of beams. The probabilistic characteristics evaluated using the proposed method are found to be matching well with those obtained from direct MCS. © 2022 Elsevier Ltd

Probabilistic Engineering Mechanics

A simple and efficient stochastic meshfree method for linear eigenvalue problems in structural mechanics

Deep foundations are conventionally being adopted in construction of various structures ranging from bridges to skyscrapers. Bored cast-in-situ piles and drilled shafts have become a common choice of deep foundations, especially in urban areas, owing to the relatively minimal construction associated noise and vibration as opposed to driven pile. However, one of the major shortcomings of bored piles is the lower skin and tip resistances due to the installation effects (stress relief). In the current practice, empirical or semi-empirical correlations are generally adopted for estimating the unit skin friction of bored pile/drilled shafts which is not necessarily taking into account the actual soil state around pile subsequent to the installation. Since the soil state (properties and stresses) in the vicinity of pile will be significantly altered due to the installation processes, studying the evolution of soil state during the various construction stages as well as the loading stage will aid to estimate the residual confining stress and thus the unit skin resistance of pile. This can be made possible using cavity expansion and contraction solutions as the stress relaxation during the excavation of hole is analogous to a cylindrical cavity contraction (unloading) problem and subsequent concrete placement and axial loading resemble a cavity re-loading (i.e. expansion) problem. This paper presents a semi-analytical cylindrical cavity contraction and expansion solution procedure to predict the residual horizontal stress and consequently the skin friction of bored pile. The proposed approach was validated using two well-documented field test data of bored piles/drilled shafts in sand. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Predicting Residual Stress State Around Bored Cast-In-Situ Piles Utilizing Cavity Contraction and Expansion Solutions

Alkali activated binders are sustainable alternatives to carbon-intensive conventional Portland cements. Although earlier studies focussed on the mechanical properties of alkali-activated binders, studies on their carbonation resistance are limited compared to Portland cement systems. Hence, the present study focuses on a systematic review of the carbonation performance of different types of alkali-activated binders, considering all the influencing parameters such as activator modulus, concentration and the nature of the precursor etc. This study also presents a comparison of the carbonation of alkali-activated binders with ordinary Portland cement and blended cement binders. The observations on carbonation resistance are presented in terms of carbonation depth, pH change, compressive strength and corrosion resistance. Moreover, the carbonation products formed in different alkali-activated binder systems and their mineralogical, as well as morphological characteristics are discussed based on the results from the thermogravimetric analysis, X-ray diffraction analysis and scanning electron microscopy. While different polymorphs of calcium carbonate are reported as the carbonated phases in conventional cementitious systems and slag-based alkali-activated binders, nahcolite was found to be the predominant carbonation product when fly ash was used as the precursor. It has also been reported that the intensity of CO2 exposure can result in different forms of carbonate phases in alkali-activated slag, with lower CO2 exposure favouring calcite formation and higher concentrations favouring the formation of vaterite. Matrix densification and crack healing due to carbonation product formation was also observed from the micrographs of carbonated alkali-activated binders, similar to what is reported for conventional cementitious systems. The differential thermogravimetric curves show wide bands in the calcium hydroxide decomposition range in alkali-activated slag binders as opposed to the narrow and distinct lime decomposition peaks in OPC and blended cement systems. The carbonation products are found to change with respect to the carbonation conditions of alkali-activated systems as well as with the type of the precursor. © 2022 Elsevier Ltd

Journal of Building Engineering

Carbonation of alkali activated binders and comparison with the performance of ordinary Portland cement and blended cement binders

Rice straw ash and sugarcane bagasse ash are two of the most abundantly available biomass ashes in India and can be used as supplementary cementitious materials in concrete. Unlike rice husk ash which is also a by-product of rice cultivation, the research studies on the use of rice straw ash as a pozzolan are highly limited. This study characterizes the microstructure of the as-received and processed rice straw ash in comparison with sugarcane bagasse ash. Moreover, the influence of these ashes on the rheological properties of cementitious system was investigated. The microstructural characterization reveals that both rice straw ash and sugarcane bagasse ash are constituted of dumbbell shaped silica-storage structures called phytoliths. Rice straw ash is found to be richer in phytoliths compared to sugarcane bagasse ash. However, the prismatic structures as seen in sugarcane bagasse ash is noticeably absent in rice straw ash. The unburnt carbon content is attributed to the fibrous network present in the ashes. The yield stress and viscosity of cement paste are found to increase with the addition of rice straw ash and sugarcane bagasse ash. Cements blended with sugarcane bagasse ash is found to have a significantly greater viscosity than rice straw ash blended cements at all levels of replacement. Mechanical processing of the ashes (sieving and grinding) to remove the coarse fibrous fraction is found to improve the rheological properties of cement blended with rice straw ash and sugarcane bagasse ash. The optimum dosage of superplasticizer required for rice straw ash and sugarcane bagasse ash blended cements were found to be 0.6% and 0.4%, respectively. © 2022 Elsevier Ltd