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

World University root node

International Conference on Advances in Construction Materials and Systems (2017)

Effect of Aggregate Gradation on Rutting Performance of Asphalt-Rubber Gap Graded Mixtures

The influence of discrete and randomly distributed polyester (PET) fibers in improving the crack resistance and water-tightness of clay barriers was studied by conducting a series of centrifuge model tests at 40 gravities using a large beam centrifuge available at Indian Institute of Technology Bombay. Model clay barriers with and without fibers were subjected to flexural distress by inducing differential settlements using a settlement simulator. Two types of clay barriers were prepared by using two different types of soil, namely bentonite amended silty soil (Soil A) and kaolin clay-sand mixture (Soil B). Digital image cross-correlation (DIC) technique was used for analyzing the images captured by a digital photo camera and a charged couple device (CCD) camera, mounted along with the model. Unreinforced soil barriers (URSB) were found to lose their water-tightness and integrity at relatively lower distortion levels compared to identical fiber reinforced soil barriers (FRSB). Also, the performance of URSB and FRSB was found to be superior for Soil A compared to Soil B. The capability of PET fibers on preservation of existing unreinforced soil barriers was also demonstrated. The strain at crack initiation, εc, for FRSB is 2.90 and 2.36 times higher than identical URSB for Soil A and Soil B, respectively. Similarly, the strain at the onset of water breakthrough, εb, for FRSB is 2.14 and 2.79 times higher than identical URSB for Soil A and Soil B, respectively. There is a significant influence of fiber inclusion in retarding the crack initiation and water breakthrough at the onset of flexural distress for both the soil types. Thus, FRSB can withstand more distortion and strain while maintaining the integrity of the clay barrier. This observed behaviour of restraining cracks and improved performance of FRSB is primarily due to the reinforcement effect achieved due to soil-fiber interactions. © 2016 Elsevier B.V.

Applied Clay Science

Centrifuge model study on the performance of fiber reinforced clay-based landfill covers subjected to flexural distress

Journal of Rock Mechanics and Geotechnical Engineering

Investigation of block foundations resting on soil–rock and rock–rock media under coupled vibrations

In response to the demands of implementing building information modeling (BIM), new roles and job titles have emerged. However, it can be argued that these roles fundamentally fall within the scope of the traditional functions of existing core professional service providers, although being carried out through different means and methods. This study examines the circumstances that have created the necessity for these new roles in the South African context and also questions the sustainability of their legitimacy. Data were collected using key informant interviews with construction professional service providers (CPSPs) in South Africa and analyzed through thematic content analysis. A deep conceptualization and new theoretical insight is developed on the phenomenon of new role creation and legitimation. It was established that new BIM role takers are legitimated to exercise authority within project teams and organizations mainly by leveraging superior knowledge as a strategic resource. By implication, they will remain legitimate only as long as the constraint prompting their creation subsists, i.e., core professionals' BIM knowledge deficiencies, thereby affirming that the new BIM roles are transitory and unsustainable.

Journal of Construction Engineering and Management

New BIM Roles' Legitimacy and Changing Power Dynamics on BIM-Enabled Projects

The objective of this study was to employ an artificial neural network (ANN) to predict asphalt-rubber (AR) rutting performance characteristics using binder properties, crumb rubber (CR) gradations, and mechanical test parameters. The scope included advanced asphalt binder rheological characterization using a dynamic shear rheometer (DSR), encompassing preparation of a total of 18 laboratory-blended AR binders with two base binders and nine CR gradations, totaling over 2,200 data points. Principles of ANNs were used to predict the three AR binder performance parameters: η, G*/sinδ, and tanδ. Eight input parameters constituting test temperature and frequency, five CR gradation components, and base binder viscosity were employed to develop the ANN model. A back-propagation learning algorithm with scaled conjugate gradient (SCG) as the training algorithm in a feed-forward, two-hidden-layer neural network with seven and three neurons, respectively, was chosen as the best ANN architecture. The statistical goodness of fit measures R for the total data set were, respectively, 0.994, 0.997, and 0.977 for η,G*/sinδ, and tanδ. ANN modeling conceptualized as part of the study indicated that rubber inclusions in asphalt binders would aid in the improvement of the materials' rutting resistance. The magnitudes of weights and biases provided in this study for the eight chosen AR binder material input parameters could be well utilized in predicting the three binder material performance parameters. Overall, it is envisaged that the algorithm developed in this research pertinent to asphalt binders' advanced rheological characterization would further the state of the art in designing rut-resistant rubber modified asphalts. © 2017 American Society of Civil Engineers.

Journal of Materials in Civil Engineering

Heuristic principles to predict the effect of crumb rubber gradation on asphalt binder rutting performance

Comprehensive modelling of urban freight operations remains a challenge in transportation research. This is partly due to the diversity of commodities transported, shipment units, vehicle types used, stakeholders' objectives (e.g. suppliers, carriers, receivers), and to the limited availability of data. Thus, existing modelling efforts require several assumptions yet have limited behavioral foundations and minimal interaction between agents. This paper proposes a new agent-based modelling framework, which considers the heterogeneity of urban freight agents and their interactions. Agents include establishments (suppliers, carriers, and receivers) and freight vehicle drivers. Agents' decisions are structured in three temporal resolutions: strategic, tactical, and operational. A single set of agents is represented throughout all modelling levels ensuring a consistent and sequential flow of information. At the strategic level, establishments' characteristics and strategic decisions are modelled. These include location choices, fleet constitution, annual production/consumption of commodities, and establishment-to-establishment commodity flows. At the tactical level, shipments are assigned to carriers, who in turn plan their operations in terms of vehicle-driver-route assignments. Finally, at the operational level, the interactions between daily operational demands and transportation network supply are simulated. The supply representation has two different resolution levels (micro or meso) allowing for either detailed or computational efficient simulation. The simulation platform is distinct from previous works, as it explicitly considers planning horizons, replicates agent decision makings/interactions and involves a structure that allows for the propagation of influences bottom-up (e.g., prior simulation travel times on future route choice). The paper describes the simulation platform, constituent models, and illustrates its capabilities using an application of the modelling framework to the city of Singapore. © 2017 The Authors. Published by Elsevier B.V.

Fulltext

Transportation Research Procedia

A multi-scale agent-based modelling framework for urban freight distribution

The focus of this research was to evaluate and improve Florida Department of Transportation (FDOT) FB-Deep software prediction of nominal resistance of H-piles, prestressed concrete piles in limestone, large diameter (&gt; 36”) open steel and concrete piles, as well as estimation of unit side friction on permanent steel casing for drilled shafts in Florida limestone. To accomplish this the following data was collected, (1) 642 dynamic load tests (DLT) and 33 static load tests on H-piles, (2) 100 DLT tests for prestressed concrete piles in Florida limestone, (3) 50 open-ended steel and concrete piles (22 piles larger than 36-in) from coastal areas in the U.S. and Asia, and (4) 17 cased drilled shafts embedded in Florida limestone. Evaluation of the H-piles revealed that generally, the piles undergo both setup and plugging after driving that is lost after a few restrikes; in addition, long piles undergo skin friction unloading. Recommendations to improve FBDeep H-pile prediction include averaging Standard Penetration Test (SPT) N values only beneath the pile tip and increasing the limiting N values to 100 for strong limestone layers. In the case of prestressed concrete piles embedded in limestone, (1) weak limestone which for the purposes of this report was classified as N &lt; 45 blows per foot, exhibit unit skin friction values more representative of soil than rock/shelly sand, (2) for competent limestone (N&gt;45) the limiting SPT N value for estimating side and tip resistance should be increased to 100, and (3) the nominal tip resistance should be estimated by averaging the SPT N values within four diameters (or pile width) “B” below the pile tip. For all limestone (weak and competent), a revised unit tip resistance for 4B SPT N averaging is recommended. For all open-ended steel and concrete cylinder piles, it was found that many piles behaved plugged per the static load test results. It was established for both FB-Deep (2015) program and American Petroleum Institute (API - 2011) method that the end bearing was the minimum of inside side friction or unit end bearing acting over the bottom soil plug; in addition, the limiting N value should be increased to 100. Finally, for a permanent cased drilled shaft, the unit skin friction in load tested shafts was found to increase with rock strength to a limiting value of 1.2 tsf; an equation of nominal resistance as well as mobilized resistance as a function of displacement is presented. The contribution of casing in drilled shafts that derive most of their side resistance from the rock socket interface should not be implemented in design, due to strain incompatibility between the cased and uncased portions of the embedded length.

University of Florida. Dept

Evaluation of Static Resistance of Deep Foundation: Phase I

A methodology for obtaining implicit constitutive representations involving the Cauchy stress and the Hencky strain for isotropic materials undergoing a non-dissipative process is developed. Using this methodology, a general constitutive representation for a subclass of implicit models relating the Cauchy stress and the Hencky strain is obtained for an isotropic material with no internal constraints. It is shown that even for this subclass, unlike classical Green elasticity, one has to specify three potentials to relate the Cauchy stress and the Hencky strain. Then, a procedure to obtain implicit constitutive representations for isotropic materials with internal constraints is presented. As an illustration, it is shown that for incompressible materials the Cauchy stress and the Hencky strain could be related through a single potential. Finally, constitutive approximations are obtained when the displacement gradient is small. © 2017, Springer International Publishing AG.

Zeitschrift fur Angewandte Mathematik und Physik

Representations for implicit constitutive relations describing non-dissipative response of isotropic materials

Limited field data are available from reinforced concrete specimens exposed to environmental conditions and subjected to severe deterioration by Alkali Silica Reaction (ASR) and/or Delayed Ettringite Formation (DEF). A large-scale reinforced concrete specimen is subject to ASR/DEF deterioration for five years. Strain measurements indicate that both transverse and longitudinal reinforcement yield within six to twelve months of field exposure. Recorded surface strains compare well with the internal steel and concrete strains. Transverse expansion strains markedly exceed longitudinal expansion strains. Although ASR/DEF deterioration may cause severe surface cracking and possible reinforcement corrosion in the long-term, its effect on the structure's load carrying capacity remains unknown at this time. © 2016 Elsevier Ltd

Construction and Building Materials

Deterioration data of a large-scale reinforced concrete specimen with severe ASR/DEF deterioration

There is a dearth for practice-based approaches to model ASR/DEF related expansion in reinforced concrete. A minimalist semi-empirical model is developed to simulate ASR/DEF induced expansion strains in reinforced concrete. The model accounts for the reinforcement ratio, the effects of externally applied compressive and tensile loads, and the variation in temperature and moisture, thus expanding the applicability of the proposed model to concrete structures exposed to field conditions. The modeled longitudinal and transverse expansion strains compare well with the measured expansion strain data from small-scale laboratory specimens, and large-scale spliced column specimens exhibiting ASR/DEF related expansion. © 2016 Elsevier Ltd