Department of Environmental and Water Resources Engineering

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

School of Civil Engineering

Permanent deformation is pavement distress that has been the root cause of failure of roads globally. With the formation of a rut, follows cracking which inevitably damages the asphalt and sub-base layers. To curb the rutting distress, this study investigates the use of nanosilica, miniaturized silica particles to the power of 10-9 to modify the binder of the asphalt concrete. The nano-silica was added at 4%, 6% and 15% by weight of bitumen into the asphalt mixture. Marshall Mix design method was used to prepare the forty-eight samples used in the study. Repeated Load Permanent Deformation (RLPD) test and Shape Memory (SM) were performed at two temperatures (25°C and 40°C). It was found that the rutting resistance and shape memory had the best performance with the addition of 15% nano-silica at 40°C. Addition of nano-silica at 15% by weight of bitumen had the best amelioration of not only permanent deformation resistance but also shape retention thus enhancing pavement performance. © Published under licence by IOP Publishing Ltd.

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Department of Structural and Geotechical Engineering

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IOP Conference Series: Earth and Environmental Science

Nano-Silica modifier asphalt concrete under rutting resistance and shape memory component

The main cause of reinforced concrete deterioration is chloride attack. Chloride ions penetrated into the concrete can destroy the passive layer around steel reinforcement provided by the high alkalinity and low pH of cement paste, activating electrochemical corrosion. Durable concrete gives more corrosion resistance of embedded steel that continuously ensures a stronger long life of the reinforced concrete structure. The concrete structures within the seashore areas allow chloride ions to easily penetrate into the concrete and reduce the life span of the structure. In this paper, the rapid chloride permeability test (RCPT) as per ASTM C1202 is presented to determine the chloride profile, concrete chloride resistivity and rate of corrosion. The specimens were prepared with concrete incorporating three different type fibres including steel, E-waste copper wire and E-glass fibres of 1.0% by volume of concrete. The RCPT was conducted for time period of 28 days, 56 days and 90 days. The final RCPT results of fibre-reinforced concrete mix with control mix concrete were compared. The test result shows that the E-glass fibre-reinforced concrete was more durable than the other concrete mixes. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Lecture Notes in Civil Engineering

Evaluation of Rapid Chloride Permeability Test on Concrete Containing Steel, E-Waste Copper Wire and E-Glass Fibres

Fracture mechanics is the field of mechanics concerned with the study of propagation of cracks in materials and recognizes the role of cracks in the performance of structures leading to damage tolerant design approach. Cracks or crack like defects is observed in many structures which may lead to their catastrophic failure under a tensile stress field. In this paper, the structural integrity of plates with surface and embedded cracks is investigated using ABAQUS FEA code and the fracture parameter—stress intensity factor (SIF)—is evaluated. Convergence study is conducted to arrive at the optimum mesh parameters using both the conventional finite element method and the extended finite element method (XFEM). The FE model is validated by comparing FE results with published numerical solutions. The effect of varying crack depth and location on SIF is studied. The FE results matched well with the closed-form solutions and experimental results. It is observed that the crack depth and its location have significant influence on SIF. The conventional finite element method requires a mesh that conforms to the crack geometry, typically with a very detailed, focused mesh at the crack tip. The crack front must be defined explicitly and must specify the virtual crack extension direction in addition to matching the mesh to the cracked geometry. XFEM gives better result for cylindrical shells without mesh refinement around crack tip. © 2021, Springer Nature Switzerland AG.

Innovative Infrastructure Solutions

Fracture analysis of plates and shells using FEM and XFEM

Seismic protection of hospital buildings is at most important as they belong to lifeline structures. Proper definition of seismic demand is essential for earthquake protection of structural components. Generation of floor response spectra assumes significant in design and analysis of structural contents which require high seismic demand. Limiting the floor acceleration/drift is found to be difficult in most of the times in traditional lateral load resisting system and is period-sensitive in addition to ductility [1]. But decoupling the floor from the building using suitable isolation schemes found to reduce the floor accelerations and displacements [2]. The paper presents an investigation into the seismic demand reduction for a chosen isolation scheme on a 10-storey hospital building which essentially lies in the descending portion of response spectrum [3]. The passive isolation scheme consists of spring and damper assembly connecting isolated floor to the building. Nonlinear time history analysis has been carried out on both the floor isolated and non-isolated building subjected to an earthquake intensity of 0.3 g. Dynamic characteristics of the building were evaluated, and apparent dynamic magnification factors were found out which are useful for generation of floor response spectra. Seismic peak floor acceleration (PFA) is one of the significant parameters influencing performance of the building contents. In addition to PFA, spectral acceleration and displacements were selected as engineering demand parameters. Based on the acceleration and drift demands, suitable floor isolation system is suggested. With the chosen floor isolation scheme, seismic demand has been found to decrease imparting higher efficiency to the system. Accurate recommendation related to displacements and floor acceleration provisions are necessary for the efficient seismic protection design of non-structural elements. © 2021, Springer Nature Singapore Pte Ltd.

Floor Response Spectra: An Investigation on Hospital Building

Auxetic is a material or a structure which has gained popularity due to its enhanced properties; they are widely used in the field of biomedical, aerospace, automotive, military and textile industry. They exhibit negative Poisson’s ratio, that is, unlike unconventional materials, they become wider when uniaxially stretched and thinner when uniaxially compressed. They exhibit enhancement in physical properties like vibration absorption, shear resistance, indentation resistance, fracture resistance and lower fatigue crack propagation. In this paper, a 3D unit cell was numerically modelled to evaluate the auxetic behaviour, and parametric analysis was done to evaluate the performance of different designs of unit cell, and it was compared with the equivalent monolithic one. Various design parameters considered were the height of the vertical connecting strut and the centre and radius of the curved strut of the core. It was found that a curved strut core shows auxetic behaviour, and as the distance of the centre of the curved strut increases, the deflection of the unit cell increased. This 3D unit cell was then numerically modelled to sandwich beam with auxetic core subjected to three-point bending. The behaviour of the structure was studied numerically using Abaqus/CAE 6.14. © 2021, Springer Nature Singapore Pte Ltd.

Flexural Behaviour of Auxetic Core Sandwich Beam

The Gulf Cooperation Council (GCC) countries are arid with very limited availability of water resources. In recent years, these countries have started an intensive program to increase the storage of groundwater through various techniques of managed aquifer recharge (MAR). Water consisting of varying quantity and quality (derived from various sources) are used via MAR techniques to increase the groundwater storage and, if possible to enhance its quality, respectively. This paper presents a review of the MAR techniques practiced in GCC countries including the implementation strategies of the different structures. Generally, seven MAR techniques are utilized in GCC countries including dams, aquifer storage and recovery (ASR) technique, aquifer storage transfer and recovery (ASTR) technique, ponds, soil aquifer treatment (SAT) technique, rooftop rainwater harvesting, and Karez/Ain system. Results indicated that ASR using excess desalinated water or treated sewage effluent (TSE) is the most used MAR technique in GCC countries, followed by the use of ASTR, dams, and ponds. Based on this review, twelve different selection criteria have been developed for GCC countries for better MAR practice in the future. © 2020, King Fahd University of Petroleum & Minerals.

Arabian Journal for Science and Engineering

Managed Aquifer Recharge in the Gulf Countries: A Review and Selection Criteria

The contamination of soil by heavy metals and metalloids is a worldwide problem due to the accumulation of these compounds in the environment, endangering human health, plants, and animals. Heavy metals and metalloids are normally present in nature, but the rise of industrialization has led to concentrations higher than the admissible ones. They are non-biodegradable and toxic, even at very low concentrations. Residues accumulate in living beings and become dangerous every time they are assimilated and stored faster than they are metabolized. Thus, the potentially harmful effects are due to persistence in the environment, bioaccumulation in the organisms, and toxicity. The severity of the effect depends on the type of heavy metal or metalloid. Indeed, some heavy metals (e.g., Mn, Fe, Co, Ni) at very low concentrations are essential for living organisms, while others (e.g., Cd, Pb, and Hg) are nonessential and are toxic even in trace amounts. It is important to monitor the concentration of heavy metals and metalloids in the environment and adopt methods to remove them. For this purpose, various techniques have been developed over the years: physical remediation (e.g., washing, thermal desorption, solidification), chemical remediation (e.g., adsorption, catalysis, precipitation/solubilization, electrokinetic methods), biological remediation (e.g., biodegradation, phytoremediation, bioventing), and combined remediation (e.g., electrokinetic- microbial remediation; washing-microbial degradation). Some of these are well known and used on a large scale, while others are still at the research level. The main evaluation factors for the choice are contaminated site geology, contamination characteristics, cost, feasibility, and sustainability of the applied process, as well as the technology readiness level. This review aims to give a picture of the main techniques of heavy metal removal, also giving elements to assess their potential hazardousness due to their concentrations. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Applied Sciences (Switzerland)

Remediation of metal/metalloid-polluted soils: A short review

Commuting adds a significant proportion to the total PM2.5 and PM1 exposure concentration, especially in urban areas. However, spatial and inter-day variations of commuter exposure concentrations are rarely assessed in India. This study investigates the personal exposure concentration of PM2.5 and PM1 in Vellore city, India while commuting in active (pedestrian and bicycle) and motorized (motorbike, car, auto-rickshaw, and bus) transport modes. A total of 312 one-way trips were completed in urban traffic route and residential route during morning and afternoon periods to assess spatial and inter-day variations. The inhaled dose per trip and inhaled dose per kilometre travelled were also estimated using exposure concentrations, minute ventilation rates, travel time, and distance travelled. Irrespective of travel mode, PM2.5 and PM1 exposure concentrations in traffic route was consistently higher than the residential route. Morning trips were highly polluted than afternoon trips in traffic route, whereas afternoon trips registered marginally higher concentration than morning trips in the residential route. Motorized transport modes were observed with the highest exposure concentration compared to active commuters in both traffic and residential routes. Median PM2.5 and PM1 exposure concentration of motorized commuters across all routes and trips ranged from 54 to 202 and 21–153 μg m−3. Car commuters experienced the highest PM2.5 and PM1 exposure concentration. Pedestrian and bicycle commuters registered maximum inhaled doses per trip in traffic and residential routes, respectively. Also, inhaled doses per kilometre travelled in active commuters were 4–8 times higher than motorized commutes. Motorbike commuters experienced the lowest doses among all six commutes. © 2020 Turkish National Committee for Air Pollution Research and Control

Atmospheric Pollution Research

Commuter exposure concentrations and inhalation doses in traffic and residential routes of Vellore city, India

Background: Particulate matter (PM) is one among the crucial air pollutants and has the potential to cause a wide range of health effects. Indian cities ranked top places in the World Health Organization list of most polluted cities by PM. Objectives: Present study aims to assess the trends, short- and long-term health effects of PM in major Indian cities. Methods: PM-induced hospital admissions and mortality are quantified using AirQ+ software. Results: Annual PM concentration in most of the cities is higher than the National Ambient Air Quality Standards of India. Trend analysis showed peak PM concentration during post-monsoon and winter seasons. The respiratory and cardiovascular hospital admissions in the male (female) population are estimated to be 31,307 (28,009) and 5460 (4882) cases, respectively. PM2.5 has accounted for a total of 1,27,014 deaths in 2017. Conclusion: Cities with high PM concentration and exposed population are more susceptible to mortality and hospital admissions. © 2021 Informa UK Limited, trading as Taylor & Francis Group.

International Journal of Environmental Health Research

Health effects of particulate matter in major Indian cities

Background: Ambient fine particulate matter (PM2.5) is one of the leading risk factors in India. The elevated levels of PM2.5 exposure concentration in India are related to higher premature mortality. However, health benefits or avoidable premature mortality by reducing PM2.5 concentration is uncertain. Objectives: Here we simulated the health benefits by assuming the achievement of 1) National Ambient Air Quality Standards of India (PM2.5 annual average = 40 μg m−3), 2) National Clean Air Programme policy (30% reduction) and 3) World Health Organization standard (10 μg m−3). Methodology: Using Environmental Benefits Mapping and Analysis Program – Community Edition (BenMAP-CE), the health benefits are estimated at national, state and district levels for various health endpoints viz., all-cause, ischaemic heart disease (IHD), chronic obstructive pulmonary disease (COPD), lung cancer and stroke. PM2.5 data, concentration-response coefficient, population, and baseline incidence rate are specified as input data in BenMAP–CE. Results: At the national level, all-cause health benefits in three simulations range from 0.79 to 2.1 million cases during 2019. Similarly, IHD, COPD, lung cancer, and stroke related health benefits are in the range of 0.28–0.68, 0.17–0.39, 0.01–0.03, and 0.14–0.34 million cases, respectively. State-level estimates showed that Uttar Pradesh, Bihar, and West Bengal are having maximum health benefits whereas north-eastern states are found with lowest estimates. Districts such as Allahabad, Lucknow, Muzaffarpur, Patna, and Sultanpur are estimated to have highest health benefits. States and districts with higher PM2.5 concentration and exposed population are found with maximum health benefits. Among the three simulations, achievement of the World Health Organization standard resulted in highest estimates. Further, the limitations and sensitivity of input parameters used in this study are discussed in detail. Conclusion: Study results highlighted the need for state and district-specific air quality management measures to increase PM2.5 related health benefits. © 2020 Elsevier B.V.