bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical analysis of fast ions transport induced by magnetic islands in HL-2A
Authors: Zhang Yue , Wang Feng , Sun Jizhong , Li Mao , Hao Guangzhou
Published: June 2024

The transport of beam ions in the presence of single/multiple tearing modes (TMs) under HL-2A geometry has been investigated by test particle method. Simulation results show that there exists a threshold behavior in the number of lost beam ions in the plasma under perturbation of a (2,1) TM with amplitude

α
0

: when the amplitude

α
0

is over a critical value, the number of lost beam ions increases linearly with

α
0

at a much faster pace. Further analysis finds that the lost beam ions have relatively higher percentage of high energy at

α
0

around the critical value. It also finds that the distribution of lost beam ions which is initially concentrated on the high field side expands gradually toward the low field side as the perturbation amplitude

α
0

increases. From the phase space analysis, it shows that the enhanced outward transport of fast ions in the presence of magnetic islands results from orbit stochasticity, which is due to the overlap of the drift islands in the interaction of fast ions with TMs. When two TMs are simultaneously present, the stochastic threshold of fast ion orbit is found to be lower than that in their individual TM case. The phase space analysis shows that in the presence of two modes with the same toroidal mode number, the modes increase the loss of fast ions when they are out of phase; however, such the effect of strengthening transport of fast ions turns to weaken when they are in phase. In contrast, when two modes each with a different toroidal mode number, their phase difference phase hardly has any effect on the transport of fast ions.
Variational data encoding and correlations in quantum-enhanced machine learning
Authors: Wang 王 Ming-Hao 明浩 , Lü 吕 Hua 桦
Published: June 2024

Leveraging the extraordinary phenomena of quantum superposition and quantum correlation, quantum computing offers unprecedented potential for addressing challenges beyond the reach of classical computers. This paper tackles two pivotal challenges in the realm of quantum computing: firstly, the development of an effective encoding protocol for translating classical data into quantum states, a critical step for any quantum computation. Different encoding strategies can significantly influence quantum computer performance. Secondly, we address the need to counteract the inevitable noise that can hinder quantum acceleration. Our primary contribution is the introduction of a novel variational data encoding method, grounded in quantum regression algorithm models. By adapting the learning concept from machine learning, we render data encoding a learnable process. This allowed us to study the role of quantum correlation in data encoding. Through numerical simulations of various regression tasks, we demonstrate the efficacy of our variational data encoding, particularly post-learning from instructional data. Moreover, we delve into the role of quantum correlation in enhancing task performance, especially in noisy environments. Our findings underscore the critical role of quantum correlation in not only bolstering performance but also in mitigating noise interference, thus advancing the frontier of quantum computing.
Influence of ion species on extraction characteristics of mixed ion beams
Authors: Xu 徐 Ao 翱 , Gan 甘 Pingping 娉娉 , Wan 万 Xiang 翔 , Shi 石 Yuanjie 元杰
Published: June 2024

The spatial distributions of different kinds of ions are usually not completely the same in the process of extracting. In order to study the reason for the different characteristics of ion extraction, a simplified simulation model of Cu+ and Cr+ ions extraction process was established by 2D3V (two-dimensional in space and three-dimensional in velocity space) particle-in-cell (PIC) method. The effects of different extraction voltages from 0 V to 500 V on the density distribution of Cu+ and Cr+ ions and the change of plasma emission surface were analyzed. On the basis of this model, the ion density distribution characteristics of Cu+ ions mixed with Li+, Mg+, K+, Fe+, Y+, Ag+, Xe+, Au+, and Pb+ ions respectively under 200-V extraction voltage are further simulated, and it is revealed that the atomic mass of the ions is the key reason for different ion density distributions when different kinds of ions are mixed and extracted, which provides support for further understanding of ion extraction characteristics.
Using a linear dynamic system to measure functional connectivity from M/EEG
Authors: Drew Jordan , Foti Nicholas , Nadkarni Rahul , Larson Eric , Fox Emily , KC Lee Adrian
Published: June 2024

Objective. Measures of functional connectivity (FC) can elucidate which cortical regions work together in order to complete a variety of behavioral tasks. This study’s primary objective was to expand a previously published model of measuring FC to include multiple subjects and several regions of interest. While FC has been more extensively investigated in vision and other sensorimotor tasks, it is not as well understood in audition. The secondary objective of this study was to investigate how auditory regions are functionally connected to other cortical regions when attention is directed to different distinct auditory stimuli. Approach. This study implements a linear dynamic system (LDS) to measure the structured time-lagged dependence across several cortical regions in order to estimate their FC during a dual-stream auditory attention task. Results. The model’s output shows consistent functionally connected regions across different listening conditions, indicative of an auditory attention network that engages regardless of endogenous switching of attention or different auditory cues being attended. Significance. The LDS implemented in this study implements a multivariate autoregression to infer FC across cortical regions during an auditory attention task. This study shows how a first-order autoregressive function can reliably measure functional connectivity from M/EEG data. Additionally, the study shows how auditory regions engage with the supramodal attention network outlined in the visual attention literature.
Observation of alpha-particles in recent D–T experiments on JET
Authors: Kiptily V.G. , Challis C.D. , Dumont R. , Fitzgerald M. , Garcia J. , Garzotti L. , Ghani Z. , Hobirk J. , Jacquet P. , Kappatou A. , Keeling D. , Kazakov Ye. , Mantica P. , Mantsinen M.J. , Sharapov S.E. , Solano E.R. , Van Eester D. , Bonofiglo P.J. , Craciunescu T. , Dal Molin A. , Eriksson J. , Goloborodko V. , Iliasova M.V. , Khilkevitch E.M. , King D. , Lengar I. , Nocente M. , Menmuir S. , Podestà M. , Poradzinski M. , Rigamonti D. , Rivero-Rodriguez J. , Stancar Z. , Shevelev A.E. , Siren P. , Sun H. , Taylor D.M. , Tardocchi M. , Beaumont P. , Belli F. , Cecil F.E. , Coelho R. , Curuia M. , Garcia-Munoz M. , Joffrin E. , Lowry C. , Lennholm M. , Lerche E. , Maggi C.F. , Mailloux J. , Marocco D. , Maslov M. , Perez Von Thun C. , Rimini F. , Zoita V. ,   JET Contributors
Published: June 2024

The fusion reaction between deuterium and tritium, D(T,n)4
He is the main source of energy in future thermonuclear reactors. Alpha-particles (4
He-ions) born with an average energy of 3.5 MeV transferring energy to the thermal plasma during their slowing down, should provide the self-sustained D–T plasma burn. The adequate confinement of α-particles is essential to provide efficient heating of the bulk plasma and steady burning of a reactor plasma. That is why the fusion-born α-particle studies have been a priority task in the second D–T experiments (DTE2) on the Joint European Torus (JET) to understand the main mechanisms of their slowing down, redistribution and losses and to develop optimal plasma scenarios. JET with Be-wall and W-divertor, enhanced auxiliary heating systems and improved energetic-particle diagnostic capabilities, producing significant population of α-particles, provided the possibility for comprehensive studying of the α-particle behaviour. Selected results of the confined and lost α-particle measurements, evidence of α-particle self-heating and assessments of the fusion performance are presented in this paper giving an opportunity for further modelling and extrapolation to the International Thermonuclear Experimental Reactor and burning plasma reactors.
Analysis of the effect of obstacles on evacuation efficiency in emergencies
Authors: Niu Heng , Zhang Yuanyuan , Li Liang , Han Yanbin , Hou Qingtao , Niu Sijie
Published: June 2024

Congestion is one of the factors that affects evacuation efficiency in emergencies. In this study, we focus on shortening the total evacuation time (TET) by setting obstacles near the exit. For this purpose, we add a probability-based obstacle avoidance strategy to modify the original social force model to simulate pedestrians’ obstacle avoidance behaviour. Using the model, we analyse the influence of the number of obstacles, their position and their distance to the wall with the exit on the TET. In addition, we discuss the relationship between the average density at the exit and the TET, which shows that crowd diversion is an effective method to alleviate congestion and shorten the TET. The simulation results show that the evacuation efficiency can be improved by reasonably setting obstacles near the exit. This study can provide some guidance for the management of crowds during emergency evacuations.
Using Finite Element Method in Seismic Analysis: A Literature Review on Diaphragm Wall
Authors: Kumar Sanjie Dutt A. , Cruz Orlean Dela
Published: June 2024

The increasing complexity of machine tools and the rising cost of procuring equipment and machine downtime have drawn researchers’ attention to the development of non-contact structural health monitoring systems. One of these is using finite element modeling software that can oversee the problem in different structures, scenarios, and applications in the environment. FE modeling is applicable and time-efficient, but its applications have limitations due to inconsistencies in the real-time of its structures. For some FE, debugging is time-consuming for extensive analyses. Also, the nonlinearity of the structures increased the complexity, leading to higher memory requirements for the software. This paper discussed past research regarding underground structures assessing seismic with FEM analysis. It also aims to define the behavior, accuracy, and applicability of software imposed in specific structures and the seismic analysis that can be applied to set the in-situ parameters and then generate it for FE modeling.
Seismic fragility comparison of FBD and DDBD designed RC frame using incremental dynamic analysis
Authors: Palsanawala T N , Gondaliya K M , Vasanwala S A
Published: June 2024

Direct displacement-based design (DDBD) is a design approach in which structures are designed for predefined displacements to withstand earthquakes within specified performance criteria. In order to defeat the drawbacks of force-based design (FBD), which is based on stiffness assumptions, the DDBD method evaluated the displacement constraint in which structure response must remain within the predetermined displacement. The fragility assessment reveals the structure’s probability of future collapse from the nonlinear analysis will help to detect the structure’s performance. In this study, Incremental dynamic analysis (IDA) is performed on a four-story reinforced concrete (RC) frame structure designed using DDBD and FBD approach to predict nonlinear structural behavior in earthquake-prone regions. The RC frame is designed to satisfy the immediate occupancy (IO) performance limit of 1% drift while taking into account the DDBD method. Sixteen ground motions with two horizontal directions mounted to various intensity levels represented by peak ground acceleration (PGA) are used to perform IDA. Fragility curves are generated from logarithms of intensity measures (IM) computed from the IDA. As a result, earthquake damage in terms of the probability of collapse and inter-storey drift ratio are compared for both approaches and using the DDBD approach, four times less PGA occurrence is observed for the IO performance limit compared to FBD.
Fatigue Damage Assessment of Tensile Specimen considering Bilinear Damage Process
Authors: Pillai Anjaly J , Talukdar Sudip
Published: June 2024

Fatigue damage assessment in design phase is an important component of structural health monitoring and is conventionally assessed using Linear Damage Rule. The effect of sequence of loading and bifurcation of the fatigue damage process has not been considered in Miner’s Linear Damage Rule. This method has been improved considering damage curve in crack initiation and crack propagation stage. The transition point from crack initiation to crack propagation known as ‘knee-point’ plays an important role in the analysis. This method is further modified by considering opening stress in crack propagation stage. The effect of sequence of loading has also been considered in the proposed methodologies. The method is illustrated with an example of dynamically induced stress in a slender bar under uniform axial time varying force. Various parameters which affect the fatigue damage of the bar like stress range, excitation frequency and damping coefficient are also studied. It is found that conventional Miner’s Linear Damage Rule estimates higher damage index compared to the present method incorporating bilinear stages of fatigue damage process.
Girder’s Response under Integral Abutment Bridge
Authors: Chaurasiya Arti , Rai Anjali
Published: June 2024

From the past evaluation and trend in bridge engineering Integral abutment bridges are gaining more popularity than conventional bridges. Kalkaji Flyover Delhi is one of the recent examples of five span continuous deck IAB. Girders are directly joined with abutment/piers without any bearings. These girders play most important role in dead load of bridge. The present study is the analytical investigation of precast concrete girder used in IAB undergone to different loads. The software used for the analysis is Csi Bridge in which a bridge of width 22 metres having the slab thickness 0.3 metres is analysed. There are five longitudinal girders (I beam of 575 mm width and 250 mm thickness) provided across the bridge’s width spaced at 2.54 metres centre to centre from each other. The girder is subjected to dead load, thermal load, backfilling, dead load with thermal load and combination of loads. Through the finite element modelling, values for different parameters for different load cases are computed. The results of this study are showing that there is no effect of backfilling for hogging but on the other hand for sagging moment the value is 12.35 kN-m. Maximum value of bending moment is due to combination of loads. Stresses developed in deck slab at the bottom are highest due to thermal loads and lowest due to backfilling. On the top of deck the stress values are highest for combination of loads. Deadload can be reduced if the Steel Plate girder is used that’s the practical implementation in integral abutment bridges.
Structural vibration control of a high-rise structure with open ground storey
Authors: Adarsh S , Sajeeb R
Published: June 2024

The rising population density, particularly in the urban areas, increased the necessity to accommodate more people within the limited space constraints. The lack of ample space for horizontal expansion has triggered the requirement of tall structures. The increasing usage of superior strength and lightweight materials for the construction of high-rise structures renders it further flexible and lightly damped, thus rendering them extra sensitive towards dynamic excitations. Open Ground Storey (OGS) buildings are buildings where ground storey is kept open mainly for the purpose of parking vehicles. OGS buildings are featured by an abrupt decline in stiffness and strength in the ground storey, and are identified to have been repetitively exhibiting inferior performance during previous earthquakes all around the globe. The present paper focus on finding the seismic responses of a (G+35) structure with OGS with the nonlinear dynamic analysis and vibration control on the OGS structure using a tuned mass damper (TMD). TMDs with mass ratios of 1% to 10% in increments of 1% are considered in the study. The seismic performance of a regular (G+35) structure without open ground storey is also considered for comparison. The seismic responses of the building with OGS are found to be more than that of a regular building without OGS. TMD has been found to reduce the seismic responses of the OGS structure considered in this study. Also, TMD with higher mass ratio is found to offer better control effectiveness.
Effect of radius of curvature on the seismic response of curved bridges
Authors: Agrawal Suyesha , Gupta Praveen Kumar
Published: June 2024

Curved bridges have seen widespread application in complex transportation networks, including interchanges and river crossings. If the displacements caused by an earthquake are too large, curved bridges have a greater risk of suffering serious damage due to the rotation of the superstructure. Since curved bridges are more susceptible to damage during earthquakes due to the effect of curvature, this factor also significantly influences the seismic behaviour of curved bridges. The present investigation has ascertained the impact of the radius of curvature on the seismic response of a bridge. The effect of ground motion characteristics and levels of shaking on the performance of bearings has also been studied. It has also been investigated how the bridge responds to seismic activity for both unidirectional and bidirectional effects. To determine the effect of the radius of curvature on the seismic response of the bridges, a non-isolated and isolated curved bridge with high damping rubber bearings has been considered. Bridges with varying radius of curvature (R= ∞, 315m, 157m, and 105m) have been modelled in the finite element-based software SAP 2000, and their response to three different ground motions has been observed. Isolation bearings in a bridge have been found to be more effective against seismic loads. The performance of an isolated bridge is superior to that of a non-isolated bridge when isolation bearings are installed in all of the piers and abutments. It is observed that a lower radius of curvature increases the deck displacement. It is also observed that bidirectional loading increases the seismic response of the curved bridge significantly relative to unidirectional loading.
Comparative Analysis of Steel Chimney Using Indian Standards (IS) & European Norms (EN)
Authors: Paswan Pragati , Mishra Abhishek
Published: June 2024

Chimneys, also known as stacks, are vertical structures used to escape harmful gases to higher elevation. The height of the chimney is chosen such that the gases are diluted by air turbulence. The chimney should be analyzed and designed in accordance with the provisions of the relevant design standards. Design codes are documents that are created for the purpose of designing a particular structure. The majority of countries have developed their own design rules based on their geographical, topographical, and climatic characteristics. Thus, efforts are being made to compare European code (EN 1993-3-2) and Indian code (IS:6533-1989) for the design of self-supported steel chimney. In this paper, the focus is on evaluating the results of seismic and wind analysis of self-supported steel chimneys. A 90m self-supported steel chimney is considered for the study. The steel chimney is modeled and analyzed using SAP2000 software for seismic zone III and wind loads of basic wind speed 47m/sec. The top lateral displacements are determined to investigate the structural reaction of the steel stack.
Influence of Recycled Coarse Aggregates in the Application of Prestressed Concrete Members-A Review
Authors: Bhargav M Tharun , Senthil K
Published: June 2024

Currently the use of Pre-stressed Concrete (PSC) has increased globally because of its effectiveness in increasing the utilization area and strength of structural members than with the usage of conventional Reinforced concrete. However due to the increase in the cost of construction, sustainable methods such as the usage of Recycled Coarse Aggregate (RCA) in place of normal aggregate have to be practiced. In this context, a review is made to know the feasibility, advantages, and disadvantages of using RCA for PSC. The requirement of Physical-Mechanical properties of concrete for PSC is compared with the properties of RCA Concrete. Serviceability and durability requirements (high compressive strength, high bond strength, low creep, and shrinkage) of Pre-stressed Concrete by using RCA and rate of change of the strength of PSC with partial replacement of coarse aggregate with RCA after 7 days is studied. It is concluded that with an increase in percentage in replacement with RCA there is a decrease in compressive strength and increase in creep and shrinkage. It is also concluded that the bond strength between reinforcement and matrix wholly depends on the compressive strength of concrete. It is suggested that the modified EMV (Equivalent mortar volume) for the mix design of concrete was found to be an increased performance than the conventional method. It is also concluded that the RCA from old precast members and admixtures such as fly ash, slag, and silica fume decrease the shrinkage and creep strain. Ultimately RCA from the existing PSC members decreases the losses in the prestress members, for effective utilization of prestress in the concrete RCA replacement up to 30% found to perform well.
Stiffness Irregularity in RC High-rise Building
Authors: Adhav A A , Birajdar B G
Published: June 2024

The present study aims at analyzing the effect of vertical stiffness irregularities in a high-rise reinforced concrete building through analytical investigation. Vertical stiffness irregularity refers to uneven distribution of story stiffness. The study focuses on vertical stiffness irregularity induced due to variation in floor-to-floor height. The study of various design codes and review of recent literature is done and subsequent comparison is presented. Further, a detailed analysis of high-rise building by using software is carried out for varied degree of stiffness at various locations of building. The findings of the study like top story displacement, story drift ratio and ductility factor are presented. The efforts have been made to co-relate the degree of irregularity and its impact on top story displacement, story drift ratio and fundamental time period of building. The top story displacement and story drift ratio found higher in buildings with vertical stiffness irregularity. Further, the nonlinear static analysis is done to assess the effect of vertical stiffness irregularity in high-rise RC building by obtaining ductility factor. It was found that vertical stiffness irregularity reduces the ductility of building, especially when present at base of building. Reduction in ductility increases the seismic vulnerability of building which may leads to structural damage or failure in some cases. This aspect must be taken into consideration while designing a building with vertical stiffness irregularity.
Seismic Evaluation of Step-Back Building and Regular Building by Using Nonlinear Static and Nonlinear Dynamic Analysis
Authors: Sharma Rajneesh , Dwivedi A.K. , Rani Varsha , Rc Bush
Published: June 2024

The structural configuration of hill slope buildings differs from that of flat land buildings. During previous earthquakes, buildings located on a hill slope suffer severe damage/collapse even in moderate earthquakes. In comparison to flat land buildings, in both plan and elevation, these hillside structures are highly uneven. Under lateral loading, these buildings may subjected to severe torsion, and collapse may occur. The Indian Standards code, like many other national codes, does not provide the necessary insight into the expected performance and associated vulnerability of hill slope buildings. Hence, the purpose of this research was to compare the seismic behaviour of structures on hill slopes to that of buildings on level ground. To estimate the seismic performance and vulnerability of the step-back building, it is modelled in software SAP 2000 v.20.2.0 and NLSA and NLTHA are performed as per FEMA-356 and ATC-40. The seismic response of hill slope buildings is compared to flat land regular buildings in terms of capacity curve, ductility demand, hinge pattern and inter-storey drift at different PGAs. It has been noted that the story directly above the uppermost foundation level is where step-back buildings typically fail. The uphill side of the step-back buildings sustains significant damage. In general, the least vulnerable buildings are those on flat land, whereas those on hill slopes are considered to be the most vulnerable.
Review on Rebar Corrosion in Alkali-Activated Concrete Subjected to Chloride-Rich Environment
Authors: Thummar Chirag , Kondraivendhan B. , Modhera Chetankumar
Published: June 2024

Rebar corrosion in concrete structures is a crucial issue for deterioration, resulting in a significant impact on Gross Domestic Product (GDP) each year worldwide. For this reason, the construction industry urgently needs novel construction materials. A sustainable alternative, Alkali-Activated Concrete (AAC), has the potential to replace conventional cement concrete. The evaluation of AAC’s durability properties has attracted significant attention. AAC’s corrosion resistance was evaluated using various mix compositions, exposure conditions, and contaminants. In marine-exposed reinforced concrete structures, chloride is the primary corrosive agent that attacks reinforcement. A systematic review is necessary to overcome the main challenges of alkali-activated concrete corrosion under chloride-induced conditions. This article provides a comprehensive literature review of the chloride-induced corrosion phenomenon in AAC. The role of various parameters comprising the mix composition of AAC, which governs its resistance to chloride-induced corrosion, has been identified and briefly discussed, also explaining different electrochemical techniques of corrosion monitoring. The Review concludes that AAC is identical to conventional cement concrete regarding chloride resistance but also illustrates the ambiguity between test results and actual conditions.
Performance of bituminous concrete mixes using waste eggshell as a bitumen modifier
Authors: Debnath Jaba , Singh Khwairakpam Lakshman
Published: June 2024

The study focuses to investigate the strength performance of bituminous concrete mixes using waste eggshells to contribute to sustainable development. The waste eggshells converted in powder form then Calcium Oxide (CaO) was obtained by calcination process at 900C temperature which was confirmed using XRD test. Then different percentage of CaO (1%, 2%, 3%, 4% and 5% by weight of bitumen) is added to the virgin bitumen as a modifier. It was observed that 3% CaO was found to be optimum modifier content. Addition of 3% CaO to virgin bitumen, the penetration and ductility values decreased by 25.3% and 46.8% respectively. But the softening point value increased by 18.4% at the same percentage of CaO. The strength performance of the bituminous mixes with CaO modified binder was evaluated in terms of Marshall Stability, Indirect Tensile Strength test and Moisture Susceptibility test. Marshall stability value, indirect tensile strength value and moisture susceptibility value of bituminous concrete mixes with 3% CaO were increased by 6.4%, 18.56% and 5.5%, respectively. It is observed from the present study that CaO used as a bitumen modifier has improved the physical properties of bituminous binder as well as the strength properties of the mixes. It indicates that bituminous mixes with CaO modified bituminous binder can also be used in high traffic and high temperature areas.
Bituminous mixes using Sisal fibre for controlling the fatigue cracks in rural roads in India
Authors: Makendran C
Published: June 2024

Pavements fail due to many factors, including traffic loading, environmental factors, and material degradation. Among these factors, fatigue cracking and rutting play a predominant role in the failure of roads. Specifically, pavements consider only two parameters: fatigue cracking and rutting, which are 20% and 20 mm thick, respectively. Fatigue cracks are formed at the bottom of the bituminous pavement layers due to tensile stresses. To improve the fatigue resistance of the pavements, this study introduced sisal fibre in bituminous mixes, where different fibre lengths 7.5, 10, 12.5, 15, and 17.5 mm were used, which were added to a calculated weight with varying percentages of 0.06, 0.12, 0.18, 0.24, and 0.30 of the total weight of aggregate. Finally, comparing the results significantly improved fatigue resistance and Marshall parameters. The study concluded that the stability of fibres, which were 10 mm in length and made up 0.6% of the sample, reached its lowest point at 12.80 KN when these fibres were mixed with 5.74% Optimum Binder Content (OBC) and 0.30% fibres measuring 17.5 mm in length.
Repairing of concrete structures using nano-silica concrete
Authors: Tripathi Anurag , Mishra Abhishek
Published: June 2024

The application of nano-particles have proven their efficacies in different domains of science such as chemial industry, engineering, medicines and many more. Numerous studies have been conducted to enhance cement concrete through various techniques. The incorporation of silica-nano-particles (SNPs) into cement concrete has been shown to be of significant importance, conferring desirable properties. Multiple investigations have been conducted in this regard. This research primarily aims to determine the optimal percentage of SNPs for replacing ordinary portland cement (OPC) in concrete to achieve the most desirable attributes, such as strength, durability, and the production of calcium-silicate-hydrate Gel (C-S-H). Such modified concrete holds substantial potential for use in the retrofitting and repair of critical concrete structures. In this study, OPC 43 grade cement is partially substituted with silica-nano-particles within the range of 2-5% to formulate M30 concrete mix (IS 10262:2009, IS 456:2000) & results are obtained for 3, 7 & 28 days behaviour. The concrete test Samples & control samples are tested for compressive strength, scanning electron microscopy(SEM) has also been performed for the chemistry of C-S-H Gel production and results are compared. As it is very well known that C-S-H’s are the main products of the hydration of portland cement and is primarily responsible factor for the strength in cement concrete. The findings reveal that the partial replacement of OPC cement with 4% SNPs yields the most favorable outcomes in terms of strength and a denser matrix. Considering that cement is the most extensively used material in the construction industry, its replacement is being explored due to the environmental impact associated with cement manufacturing, including the release of CO2 emissions and greenhouse gases (GHG), thereby contributing to global climate change. The estimated carbon footprint is approximately 915 kilograms of CO2 emitted per 1000 kilograms of cement production.
Optimizing Opening Positions for Net Zero Construction Waste: A Methodology for Sustainable Building Design.
Authors: Sruthi Priya N , Pavithra Raj J S , Arunachalam S V , Krithiga Devi V , Amalan Sigmund Kaushik S
Published: June 2024

India currently generates over 277 million tonnes (MT) of solid waste each year, a number projected to soar to 387 million tonnes by 2030. A mere 20% of this waste (55 MT) is treated annually, while the remaining 80% (221 MT) ends up in landfills. The nation additionally produces 150 million tonnes of construction and demolition waste annually, with a paltry 1.5% (2.3 MT) being recycled. The Indian Green Building Council stipulates that construction waste exceeding 5% during construction is unacceptable. This paper proposes a methodology to achieve net zero construction waste by optimizing the placement of openings for Porotherm bricks. The goals include design optimization without altering the Window-to-Wall Ratio (WWR) and reducing cut block usage for Porotherm bricks by repositioning openings. The study analyzes available brick sizes and working practices, and calculates material waste for the base case, and, subsequently for the optimized case. Material waste percentages are compared, revealing significant reductions, with cut block wastage dropping from 12% to 0.6% in vertical adjustments and from 8% to 3% in horizontal adjustments. This research aligns with IGBC standards, aiding designers in achieving net zero waste in construction.
Investigation on properties of Pervious Concrete incorporating Lime Calcined Clay Cement (LC3)
Authors: Tripathi Shivam Mani , Kumar Kuldeep
Published: June 2024

By the end of 2050, annual cement production will probably exceed 5 million metric tonnes due to an increase in output every year. Ordinary Portland Cement is produced at a rate of about 3.6 billion metric tonnes annually [1]. A tonne of carbon is emitted into the environment for every metric tonne of cement produced, leading to environmental degradation. Another issue faced from the perspective of sustainability is urban flooding which prevents the recharge of groundwater. Also, the cost of mitigating the flooding problem through adequate drainage system is too expensive. This study aims to add significant addressal to both the above two problems by analysing the behaviour of pervious concrete prepared by using Lime Calcined Clay Cement (LC3). LC3 compositions with 30%,40% and 50% replacement of Ordinary Portland Cement with Lime Calcined Clay (LC2) were taken into study. Determination of most optimum LC3 mix was done and the mix design for pervious concrete was carried out. Pervious concrete was tested for its mechanical and hydraulic/durability properties. The results showed that LC3-30 yielded the highest compressive strength, lowest setting time and lowest water content requirement for standard consistency. The pervious concrete prepared with LC3-30 also gave comparable strength results when compared with OPC pervious concrete. However, no significant difference was found in hydraulic properties of the two concretes. LC3 shows a great potential in wide range applications of pervious works such as Pervious Concrete Pavements (PCP) and roofing. The study concludes that use of Lime Calcined Clay Cement can very well be incorporated to create economic, lightweight and sustainable structures.
Influence of Silica Fume and Fly Ash with Quarry dust on Steel Fiber Concrete
Authors: Kapgate Sudhir , Pote Amol , Ambadkar Swati
Published: June 2024

Concrete is possibly the most exhaustively elaborate progression material no matter what some acquired issue. Eventually a days, mix of added substances are getting unquestionable quality. Scientists have zeroed in on fiber created concrete, fly ash concrete and silica-fume concrete independently; yet as of in the somewhat late past, the overview isn't done on steel fiber with expansion of silica-fume and fly ash in concrete. Silica fume(SF) contain in 5 % by substantial weight of cement and fly ash (FA) contents( 5% to 25%) of substantial weight of cement and halfway uprooting of fine sand with different level of quarry dust (5% to 25%) were examined. Steel fiber having a span of 50 mm and substance of 1% by substantial weight of binder, are supplementary for silica-fume fly ash and quarry dust concrete(SF-FAQD). In this work, the mechanical properties of conventional concrete and silica-fume fly ash quarry dust steel fiber created concrete(SFFAQDSF) are examined. This paper produce the compressive strength, split tensile strength and flexural strength. From the study it have been accepted that the abrogating genuinely 20% of fine sand by quarry dust mix improved quality outcomes in standard with the standard cement.
Evaluation of Mortar Properties Utilizing Partial Cement Substitution with Jarosite
Authors: Gared Om Prakash , Gaur Arun , Khichad Jeetendra Singh , Somani Prakash , Sain Amit
Published: June 2024

This experimental study examines the use of Ordinary Portland Cement 43 grade in combination with jarosite as a partial cement substitute. Various cement pastes were formed, including a control paste without jarosite (J0) and pastes (J5 to J30) with 5%, 10%, 15%, 20%, 25%, and 30% jarosite replacement. The objective of this study is to evaluate the effect of jarosite on the normal consistency, initial setting time, and ultimate setting time of cement paste. Incorporating up to 30% jarosite as a cement substitute significantly increases the normal consistency, initial setting time, and ultimate setting time compared to the control mix by 43.10%, 96.10%, and 22.70%, respectively. The results demonstrate the potential of jarosite as an advantageous replacement material for improving mortar properties. Notably, mixture J15 has the highest compressive strength, measured 37.42 N/mm2 at 7 days and 51.37 N/mm2 at 28 days. Although compressive strength decreases with increasing levels of jarosite replacement, it remains preferable to that of the control mix up to J25.
Valorisation of pond ash as replacement of fine aggregate in cement mortars for practical applications
Authors: Sharma Sandesh , Vyas Ashok Kumar
Published: June 2024

Waste generated during the coal combustion process in thermal power plant is of major concern from disposal point of view. The majority of waste consists of pond ash generated during coal combustion process in thermal power plants. This study aims to use pond ash as a replacement for river sand in cement mortars. The river sand was replaced by pond ash up to 100%, by volume. The mechanical properties were evaluated for 1:4 (cement: sand) mortar mix proportions. The compressive strength of 1:4 mix with 30% replacement of river sand was observed increased by 27%, as compared to control mix. Similarly, tensile bond strength at 30% replacement was increased by 15% as compared to control mix. On the other hand, drying shrinkage was observed to increase by 35% as compared to control mix. Overall, the general mechanical properties like compressive strength, tensile bond strength, adhesive strength, etc. were found to increase up to the replacement of 50% of river sand. Thus, it can be concluded that up to 30% replacement level, almost all the mechanical properties improved.
Impact Resistance of Treated Recycled Aggregate Concrete: Drop Weight Test
Authors: Kumar Amit , Singh Gyani Jail
Published: June 2024

The present study deals with recycled aggregate concrete (RAC) performance against impact loads. The drop weight test determines RAC’s strength and impact energy absorption capacity. Recycled concrete aggregates (RCAs) with different qualities (physical and mechanical properties) are used to prepare the RAC mix. The RAC is treated with three different mechanical treatments with varying charges and drum revolutions. It is observed that quality improvisation in RCA improves RAC impact resistance. A strong correlation between the RCA abrasion value and the RAC impact energy is observed, with an R2 value of 0.79. Additionally, a good correlation holds between the RCA crushing value and the impact energy of RAC with an R2 value of 0.61. Furthermore, RAC’s impact resistance can be enhanced by reducing its brittleness index (BI). The BI of RAC decreases as RCA quality improves. A strong correlation is also held between the BI and the impact energy of RAC with an R2 value of 0.98. The impact energy absorbing capacity of RAC’s with treated RCA is increased by up to 48.35% compared to RAC with untreated RCA. RAC composed with improved quality RCA has an impact energy of 0.92 fractions of natural aggregate concrete (NAC). The impact energy of concrete built from untreated recycled concrete aggregate (URCA) is only 0.62 fraction of the impact energy of concrete made from NA.
A comparative study on life cycle analysis of cold mix and foamed mix asphalt
Authors: Meena Pinki , Ransinchung RN GD , Kumar Praveen
Published: June 2024

Cold mix asphalt (CM) technology is more sustainable and environmentally friendly than hot mix asphalt (HM) technology. The cold mixtures are prepared with aggregates, asphalt emulsion, and water at ambient temperature. The cold mix is used to achieve economic and ecological benefits but is used to a limited extent due to its low strength and high-water sensitivity. Some additives like Ordinary Portland cement, chemical stabilizers, fibers, cement kiln dust, limestone, and fly ash are added to enhance the strength and stability of cold mix asphalt and reduce the susceptibility to moisture. Foamed mix asphalt (FMA) is a unique pavement construction method for enhancing new granular materials. Cold water and air molecules are injected into the Writgen WLB 10S machine’s bitumen expansion chamber to produce foamed bitumen. When hot bitumen mixes with cold water, foam creates, and bitumen bubbles emerge during the instantaneous foaming process, known as foaming. The bitumen collected in a cylindrical bucket during foaming is known as foamed bitumen, and the foamed bitumen is used as a binder during mix design and has a low viscosity. Fundamental indicators of FMA are (i) expansion ratio and (ii) half-life. This paper reflects the life cycle analysis (LCA) of CM to hot mix based on different parameters like energy consumption and carbon emission in the cradle-to-gate stages incorporating the effects of various foaming agent contents. Also, the LCA method estimates greenhouse gas emissions at different stages of production, transport, and pavement laying at the site. The greenhouse gas emission is responsible for global warming.
Use of Sustainable Material as Column Filler in Soft Clay Bed Reinforced with Stone Column: Numerical Study
Authors: Srijan  , Somra Kevin , Kharra Pooja , Singh Sagar
Published: June 2024

Soil reinforcement is technique to improve the engineering characteristics of soil. For stabilizing the problematic soils (soft clay), a number of strengthening techniques are available, including the employment of thermal techniques, portland cement, lime, fly ash, ground freeing, jet grouting, and prefabricated vertical drains. Similarly, one of the most popular procedures for improving soil is using stone columns, which have been used all over the world to improve structures built on soft clay by increasing their bearing capacity and lowering total and differential settlements. Consolidation is accelerated by the function of stone columns as vertical drains. In this paper, Steel slag, an industrial waste, is used as a column filler material, which can act as a sustainable material and will also address the current environmental concern. Using steel slag for soil stabilization can be an economical and ecologically conscious way to extract solid waste. To explore the various behavioural responses of virgin soft clay beds and clay beds built with stone columns, a numerical analysis was done. Based on the stone column’s deformation criteria and the soft clay bed’s settlement criteria, a comparison between the two was made.
Enhancing Subgrade Properties of Black Cotton Soil through the Combined Use of Sugarcane Bagasse Ash and Ceramic Waste Powder
Authors: Gouda Jagdish , Santosh B. , Sitarami Reddy D. , Vijay Kakade B.
Published: June 2024

This study explores the potential of Sugarcane Bagasse Ash (SBA) and Ceramic Waste Powder (CWP) in enhancing the poor black cotton (BC) soils, known for their swelling and shrinking tendencies due to high clay content. BC soils can compromise construction stability when exposed to moisture. The research involves mixing BC soil with varying proportions of SBA and CWP: 2.5% SBA and 5% CWP, 5% SBA and 10% CWP, 7.5% SBA and 15% CWP, and 10% SBA and 20% CWP. Laboratory tests show that higher SBA and CWP ratios reduce plasticity, free swell index, and Optimum Moisture Content (OMC) in the soil. This indicates that SBA and CWP additions mitigate soil plasticity and swelling. Moreover, parameters such as Maximum Dry Density (MDD), California Bearing Ratio (CBR), and unconfined compressive strength improve as SBA and CWP content increases, indicating enhanced soil strength. Laboratory findings support using up to 7.5% SBA and 15% CWP for effective subgrade soil stabilisation. A Plaxis 2D model confirms that these proportions significantly enhance pavement subgrade stability. In summary, this study demonstrates the positive impact of SBA and CWP on BC soils, reducing plasticity and swelling and improving soil strength. Using specific proportions of SBA and CWP effectively enhances subgrade soil stability, as verified by Plaxis 2D modelling.
Application of the HEC-HMS model to generate a flood hydrograph of an extreme event in a tropical basin
Authors: Babu Shruthi H , Sathish Kumar D
Published: June 2024

Hydrologic modeling using computer models has gained much attention in extreme flood event studies. Hydrologic Engineering Center Hydrologic Modelling System (HEC-HMS) is an extensively used software for streamflow generation in the hydrologic domain. This pilot study employs the HEC-HMS model in generating streamflows in the Chaliyar river basin, Kerala. Adequate representation of various water balance components of the hydrologic cycle is necessary for computing the surface and subsurface calculations. It is attained by combining appropriate sub-processes in the hydrological models. Remote sensing techniques integrated with Geographic Information Systems (GIS) are used in deriving the catchment characteristics. The simple canopy and surface methods are used to calculate the interception losses. The deficit-constant method is applied to estimate the infiltration losses, and the Clark unit hydrograph transforms the rainfall into runoff. The Muskingum method is used to route the reach segments within the watershed. Hydrometeorological data of the most influencing stations for the upstream Chaliyar basin are obtained by regionalization using the Thiessen polygon method. Daily precipitation data from four rain gauge stations, namely, Ambalavayal, Edakkara, Nilambur, and Manjeri, are used as the forcing inputs to the model. The streamflow data obtained from the Kuniyil gauge station is used to calibrate and validate the model. Various forecast skill scores like Probability of Detection (POD) and False Alarm Rate (FAR) are calculated from the categorical forecasts to quantify the forecast accuracy of the developed model. The model is used to simulate the intense flood event of 2019 in the Chaliyar basin.