Search results for: lightweight concrete slab
485 On Demand Transport: Feasibility Study - Local Needs and Capabilities within the Oran Wilaya
Authors: Nadjet Brahmia
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The evolution of urban forms, the new aspects of mobility, the ways of life and economic models make public transport conventional collective low-performing on the majority of largest Algerian cities, particularly in the west of Algeria. On the other side, the information and communication technologies (ICT) open new eventualities to develop a new mode of transport which brings together both the tenders offered by the public service collective and those of the particular vehicle, suitable for urban requirements, social and environmental. Like the concrete examples made in the international countries in terms of on-demand transport systems (ODT) more particularly in the developed countries, this article has for objective the opportunity analysis to establish a service of ODT at the level of a few towns of Oran Wilaya, such a service will be subsequently spread on the totality of the Wilaya if not on the whole of Algeria. In this context, we show the different existing means of transport in the current network whose aim to illustrate the points of insufficiency accented in the present transport system, then we discuss the solutions that may exhibit a service of ODT to the problem studied all around the transport sector, to carry at the end to highlight the capabilities of ODT replying to the transformation of mobilities, this in the light of well-defined cases.Keywords: mobility, on-demand transport, public transport collective, transport system
Procedia PDF Downloads 349484 The Anatomy of Inter-Religious Conflict in Northern Nigeria: A Conflict without Peace Education
Authors: Shehu Hashimu
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Ever since the independence, Northern Nigeria has been experiencing a flashpoint of all sorts of conflict ranging from ethnoreligious, intra-religious, and inter-religious violence; many people are of the view and worrisome that indeed the region (North) is becoming a religious-political battle-ground. The trends of violence associated with these conflicts are a reflection of high level of misunderstanding, misinform unpolitical zeal toward uplifting peace education for greater enhancement among the religious, ethnic group or sects in the northern region. The aims of this paper, among other things, are to outline the misconception on the term inter-religious conflict. It is justifiable to state the brief historical antecedence of the making of contemporary Northern Nigeria and how conflict is fluctuating over and over without concrete resolution is another concern of the paper. The desirability of peace education in enhancing cordial relations and cementing potholes among various religious sects in the region (Northern Nigeria) cannot over emphasized considering the pivotal role play toward national cohesion; therefore, this paper strategically made a lengthy discourse for elaborations. In the conclusion aspect of it, the paper outline some relevant recommendation and suggestions for viable co-existence if properly implemented.Keywords: anatomy, inter-religious, conflict, peace education
Procedia PDF Downloads 238483 An Ultrasonic Signal Processing System for Tomographic Imaging of Reinforced Concrete Structures
Authors: Edwin Forero-Garcia, Jaime Vitola, Brayan Cardenas, Johan Casagua
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This research article presents the integration of electronic and computer systems, which developed an ultrasonic signal processing system that performs the capture, adaptation, and analog-digital conversion to later carry out its processing and visualization. The capture and adaptation of the signal were carried out from the design and implementation of an analog electronic system distributed in stages: 1. Coupling of impedances; 2. Analog filter; 3. Signal amplifier. After the signal conditioning was carried out, the ultrasonic information was digitized using a digital microcontroller to carry out its respective processing. The digital processing of the signals was carried out in MATLAB software for the elaboration of A-Scan, B and D-Scan types of ultrasonic images. Then, advanced processing was performed using the SAFT technique to improve the resolution of the Scan-B-type images. Thus, the information from the ultrasonic images was displayed in a user interface developed in .Net with Visual Studio. For the validation of the system, ultrasonic signals were acquired, and in this way, the non-invasive inspection of the structures was carried out and thus able to identify the existing pathologies in them.Keywords: acquisition, signal processing, ultrasound, SAFT, HMI
Procedia PDF Downloads 96482 Development and Characterization of a Bio-Sourced Composite Material Based on Phase Change Material and Hemp Shives
Authors: Hachmi Toifane, Pierre Tittelein, Anh Dung Tran Le, Laurent Zalewsi
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This study introduces a composite material composed of bio-sourced phase-change material (PCM) of plant origin combined with hemp shives, developed in response to environmental challenges in the construction sector. The state of the art emphasizes the low thermal storage capacity of bio-based materials and highlights increasing need for developing sustainable materials that offer optimal thermal, mechanical, and hydric performances. The combining of PCM's thermal properties and hygric properties of hemp shives results in a material that combines lightness, strength, and hygrothermal regulation. Various formulations are being assessed and compared to conventional hemp concrete. Thermal characterization includes the measurements of thermal conductivity and numerical simulations to evaluate the thermal storage capacity. The results indicate that the addition of PCM significantly enhances the material's thermal storage capacity, positioning this one as a promising, eco-friendly solution for sustainable construction and for improving the energy efficiency of buildings.Keywords: hemp composite, bio-sourced phase change material, thermal storage, hemp shives
Procedia PDF Downloads 32481 Investigation of Polypropylene Composite Films With Carbon Nanotubes and the Role of β Nucleating Agents for the Improvement of Their Water Vapor Permeability
Authors: Glykeria A. Visvini, George N. Mathioudakis, Amaia Soto Beobide, Aris E. Giannakas, George A. Voyiatzis
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Polymeric nanocomposites have generated considerable interest in both academic research and industry because their properties can be tailored by adjusting the type & concentration of nano-inclusions, resulting in complementary and adaptable characteristics. The exceptional and/or unique properties of the nanocomposites, including the high mechanical strength and stiffness, the ease of processing, and their lightweight nature, are attributed to the high surface area, the electrical and/or thermal conductivity of the nano-fillers, which make them appealing materials for a wide range of engineering applications. Polymeric «breathable» membranes enabling water vapor permeability (WVP) can be designed either by using micro/nano-fillers with the ability to interrupt the continuity of the polymer phase generating micro/nano-porous structures or/and by creating micro/nano-pores into the composite material by uniaxial/biaxial stretching. Among the nanofillers, carbon nanotubes (CNTs) exhibit particular high WVP and for this reason, they have already been proposed for gas separation membranes. In a similar context, they could prove to be promising alternative/complementary filler nano-materials, for the development of "breathable" products. Polypropylene (PP) is a commonly utilized thermoplastic polymer matrix in the development of composite films, due to its easy processability and low price, combined with its good chemical & physical properties. PP is known to present several crystalline phases (α, β and γ), depending on the applied treatment process, which have a significant impact on its final properties, particularly in terms of WVP. Specifically, the development of the β-phase in PP in combination with stretching is anticipated to modify the crystalline behavior and extend the microporosity of the polymer matrix exhibiting enhanced WVP. The primary objective of this study is to develop breathable nano-carbon based (functionalized MWCNTs) PP composite membranes, potentially also avoiding the stretching process. This proposed alternative is expected to have a better performance/cost ratio over current stretched PP/CaCO3 composite benchmark membranes. The focus is to investigate the impact of both β-nucleator(s) and nano-carbon fillers on water vapor transmission rate properties of relevant PP nanocomposites.Keywords: carbon nanotubes, nanocomposites, nucleating agents, polypropylene, water vapor permeability
Procedia PDF Downloads 64480 Mechanical Behavior of Sandwiches with Various Glass Fiber/Epoxy Skins under Bending Load
Authors: Emre Kara, Metehan Demir, Şura Karakuzu, Kadir Koç, Ahmet F. Geylan, Halil Aykul
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While the polymeric foam cored sandwiches have been realized for many years, recently there is a growing and outstanding interest on the use of sandwiches consisting of aluminum foam core because of their some of the distinct mechanical properties such as high bending stiffness, high load carrying and energy absorption capacities. These properties make them very useful in the transportation industry (automotive, aerospace, shipbuilding industry), where the "lightweight design" philosophy and the safety of vehicles are very important aspects. Therefore, in this study, the sandwich panels with aluminum alloy foam core and various types and thicknesses of glass fiber reinforced polymer (GFRP) skins produced via Vacuum Assisted Resin Transfer Molding (VARTM) technique were obtained by using a commercial toughened epoxy based adhesive with two components. The aim of this contribution was the analysis of the bending response of sandwiches with various glass fiber reinforced polymer skins. The three point bending tests were performed on sandwich panels at different values of support span distance using a universal static testing machine in order to clarify the effects of the type and thickness of the GFRP skins in terms of peak load, energy efficiency and absorbed energy values. The GFRP skins were easily bonded to the aluminum alloy foam core under press machine with a very low pressure. The main results of the bending tests are: force-displacement curves, peak force values, absorbed energy, collapse mechanisms and the influence of the support span length and GFRP skins. The obtained results of the experimental investigation presented that the sandwich with the skin made of thicker S-Glass fabric failed at the highest load and absorbed the highest amount of energy compared to the other sandwich specimens. The increment of the support span distance made the decrease of the peak force and absorbed energy values for each type of panels. The common collapse mechanism of the panels was obtained as core shear failure which was not affected by the skin materials and the support span distance.Keywords: aluminum foam, collapse mechanisms, light-weight structures, transport application
Procedia PDF Downloads 390479 The Interrelations between Niemeyer’s Works and the Concept of Typology: A Computer Based Analysis of Form and Structure
Authors: Aline M. C. Santoro, João C. Pantoja, Eduardo P. Rossetti
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While the aim of the modernist movement was to deny known typology, the creation of a new formal language also gave it new meaning, which was now related to Form. This is specifically true in the modern capital of Brazil, where Niemeyer sought to demonstrate the manner in which the new materials available, such as reinforced concrete, were able to produce innovative forms. With this study, we aim to demonstrate the relationship between Niemeyer’s forms and the topological typology known as tessellation, through the presentation of two case studies, the Monument to Caxias and the Saint George Orthodox Church. At a first glance, our purpose is to present the definition of Form, especially with relationship to the works of Niemeyer, seeking to identify in them the concepts presented by Moussavi. Afterwards, we will use a computer-based approach to study and model the forms of two of his buildings with the McNeel Rhinoceros program, where, with the aid of diagrams and renderings, we will be able to clearly and legibly represent their organic forms and further understand their structural systems. When we recognise the concept of typology as a starting point for structural form, it can be concluded that the case studies presented here are encompassed by the typology presented by Moussavi since they derive from his basic structural systems.Keywords: form, Niemeyer, structure, typology, topology
Procedia PDF Downloads 190478 Behaviour and Design of the Candle-Loc Inter-Module Connection in High-Rise Modular Buildings under Seismic Action
Authors: Alessandro Marzucchini, Yie Sue Chua, Andrew Lian, Richard Shonn Mills
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A unique, fast and easy installed inter-module connection named Candle-Loc was developed and applied in several high-rise steel and reinforced concrete modular buildings in Singapore and Hong Kong, China. However, its effect on the global behaviour of modular buildings in high seismic zones was not studied. Therefore, the design concept and the structural performance of each component in this connection was investigated through analytical approach. Response spectrum, linear time-history, and nonlinear time-history analyses were conducted to investigate the effects of the different joint models of the Candle-Loc in the global analysis of high-rise buildings under high seismic loads. It is found that it is important to assess the level of plasticity developed in the inter-module connection under high seismic loads. The ductility of the lateral force resisting system influences the amount of load taken by the inter-module connections.Keywords: high-rise, inter-module connection, nonlinear, seismic, time-history analysis
Procedia PDF Downloads 163477 Estimating Pile Toe Levels for Capacity Assessment of Piers and Wharves in the Philippines
Authors: Ailvy Faith Zamora, Serj Donn David, Michael Anderson
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There are a number of decades-old piers and wharves in Manila, Philippines, that are currently being used for container and bulk cargo handling port operations. These structures fulfill a very important role in the economy and hence have undergone rehabilitation and assessment of capacity to accommodate current and future operational requirements. The capacity assessment would include structural and pile geotechnical evaluation. Unfortunately, old marine structures in the Philippines may not have a complete set of as-built information. In certain instances, critical information, such as pile toe levels, is missing in the documentation. A combination of direct tests, geophysical tests, and numerical analysis/modelling has been performed to estimate existing pile toe levels of open-type piers and anchored quay wall wharves in Manila. These techniques were applied to both concrete and steel piles. This paper presents the tools utilized, testing setup, and techniques used for estimating toe levels of existing piles for certain structures, including the challenges encountered and applied solutions.Keywords: geophysical testing, pile toe level, structural assessment, piers, wharves
Procedia PDF Downloads 115476 Shotcrete Performance Optimisation and Audit Using 3D Laser Scanning
Authors: Carlos Gonzalez, Neil Slatcher, Marcus Properzi, Kan Seah
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In many underground mining operations, shotcrete is used for permanent rock support. Shotcrete thickness is a critical measure of the success of this process. 3D Laser Mapping, in conjunction with Jetcrete, has developed a 3D laser scanning system specifically for measuring the thickness of shotcrete. The system is mounted on the shotcrete spraying machine and measures the rock faces before and after spraying. The calculated difference between the two 3D surface models is measured as the thickness of the sprayed concrete. Typical work patterns for the shotcrete process required a rapid and automatic system. The scanning takes place immediately before and after the application of the shotcrete so no convergence takes place in the interval between scans. Automatic alignment of scans without targets was implemented which allows for the possibility of movement of the spraying machine between scans. Case studies are presented where accuracy tests are undertaken and automatic audit reports are calculated. The use of 3D imaging data for the calculation of shotcrete thickness is an important tool for geotechnical engineers and contract managers, and this could become the new state-of-the-art methodology for the mining industry.Keywords: 3D imaging, shotcrete, surface model, tunnel stability
Procedia PDF Downloads 283475 Illuminating Regional Identity: An Interdisciplinary Exploration in Saskatchewan
Authors: Anne Gibbons
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Both inside and outside of academia, people have sought to understand the “sense of place” of various regions, many times over and for many different reasons. The concept of regional identity is highly complex and surrounded by considerable contention. There are multiple bodies of research on regional identity theory in many different disciplines and even across sub-disciplinary classifications. Each discipline takes a slightly different angle or perspective on regional identity, resulting in a fragmented body of work on this topic overall. There is a need to consolidate this body of increasingly fragmented theory through interdisciplinary integration. For the purpose of this study, the province of Saskatchewan will serve as an exemplar for exploring regional identity in a concrete context. Saskatchewan can be thought of as a ‘functional region,’ with clear boundaries and clear residency, from which regional identity can be studied. This thesis shares the outcomes of a qualitative study grounded in a series of group interviews with askatchewan residents, from which it is concluded that the use of interdisciplinary theory is an appropriate approach to the study of regional identity. Regional identity cannot be compartmentalized; it is a web of characteristics, attributes, and feelings that are inextricably linked. The thesis thus concludes by offering lessons learned about how we might better understand regional identity, as illuminated through both interdisciplinary theory and the lived experiences and imaginations of people living in the region of Saskatchewan.Keywords: interdisciplinary, regional identity, Saskatchewan, tourism studies
Procedia PDF Downloads 519474 Effect of Concentration of Alkaline and Curing Temperature on Compressive Strength of Geopolymer Concert
Authors: Nursah Kutuk, Sevil Cetinkaya
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Geopolymers are becoming new concrete materials to use alongside cement, which are formed due to reaction between alumino-silicates and oxides with alkaline media. Silicates obtained from natural minerals or industrial wastes are used for geopolymer synthesis. Geopolymers have recently received wide attention because of their advantages over other cementitious material like Portland cement. Some of the advantages are high compressive strength, low environmental impact, chemical and fire resistance and thermal stability. In this study, geopolymers were prepared by using inorganic materials such as kaolinite and calcite. The experiments were carried out by varying the concentration of NaOH as 5, 10, 15 and 20 M, and at cure temperature of 22, 45 and 65 °C. Compressive strengths for each mixes at each cure temperature were measured. Results of the analyses indicated that the compressive strength of geopolymers did not increase steadily with increasing concentration of NaOH, but did increase steadily with increasing cure temperature. We examined the effect Na2SiO3/NaOH weight ratio on the properties of the geopolymers, too. It was seen that Na2SiO3/NaOH weight ratio was also important to prepare geopolymers that can be applied to construction industry.Keywords: geopolymers, compressive strength, kaolinite, calcite
Procedia PDF Downloads 289473 Monitoring Cellular Networks Performance Using Crowd Sourced IoT System: My Operator Coverage (MOC)
Authors: Bassem Boshra Thabet, Mohammed Ibrahim Elsabagh, Mohammad Adly Talaat
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The number of cellular mobile phone users has increased enormously worldwide over the last two decades. Consequently, the monitoring of the performance of the Mobile Network Operators (MNOs) in terms of network coverage and broadband signal strength has become vital for both of the MNOs and regulators. This monitoring helps telecommunications operators and regulators keeping the market playing fair and most beneficial for users. However, the adopted methodologies to facilitate this continuous monitoring process are still problematic regarding cost, effort, and reliability. This paper introduces My Operator Coverage (MOC) system that is using Internet of Things (IoT) concepts and tools to monitor the MNOs performance using a crowd-sourced real-time methodology. MOC produces robust and reliable geographical maps for the user-perceived quality of the MNOs performance. MOC is also meant to enrich the telecommunications regulators with concrete, and up-to-date information that allows for adequate mobile market management strategies as well as appropriate decision making.Keywords: mobile performance monitoring, crowd-sourced applications, mobile broadband performance, cellular networks monitoring
Procedia PDF Downloads 389472 Phonetics Problems and Solutions for 5th Grade Students of Turkish Language as a Foreign Language in Demirel College in 2015-2016 Academic Year
Authors: Huseyin Demir
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Foreign language learners are able to make mistakes in their pronunciation and writing when they encounter with alphabetical indications that are not available in their own language. The fifth-grade students who learn Turkish language at Demirel College in Georgia constitute the concrete example. ‘F’, ‘y’, ‘ö’, ‘ü’ letters in the Turkish alphabet are the most common mistakes they make. After a careful comparative linguistic study, it was found out that the mistakes caused by the fact that these signs were not available in Georgian. These problems have been tried to be solved through comparative language teaching method by using the pronunciation possibilities in other languages, which are spoken or known by students. First of all, other languages known by students are identified, the similar pronunciation difficulties in Turkish are also found in those languages in order to minimize the pronunciation problem in Turkish, pronunciation possibilities are that are available in those language are utilized. In this context, visual animations are made for pronunciation of English words such as year (yr), earn (örn), fair (fêir) and made student familiar with pronunciation with these words through repetition. With this study, it is observed that student’s motivation has been increased and with these indications, student’s mistakes are minimized.Keywords: pronunciation, Demirel college, motivations, Turkish as a foreign language
Procedia PDF Downloads 244471 Influence of Silica Fume on the Hydration of Cement Pastes Studied by Simultaneous TG-DSC Analysis
Authors: Anton Trník, Lenka Scheinherrová, Robert Černý
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Silica fume is a by-product of the ferro-silicon and silicon metal industries. It is mainly in the form of amorphous silica. Silica fume belongs to pozzolanic active materials which can be used in concrete to improve its final properties. In this paper, the influence of silica fume on hydration of cement pastes is studied using differential scanning calorimetry (DSC) and thermogravimetry (TG) at various curing times (2, 7, 28, and 90 days) in the temperature range from 25 to 1000 °C in an argon atmosphere. Samples are prepared from Portland cement CEM I 42.5 R which is partially replaced with the silica fume of 4, 8, and 12 wt.%. The water/binder ratio is chosen as 0.5. It is identified and described the liberation of physically bound water, calcium–silicate–hydrates dehydration, portlandite and calcite decomposition in studied samples. Also, it is found out that an exothermic peak at 950 °C is observed without a significant mass change for samples with 12 wt.% of silica fume after two days of hydration. This peak is probably caused by the pozzolanic reaction between silica fume and Portland cement. Its size corresponds to the degree of crystallization between Ca and Si. The portlandite content is lower for the samples with a higher amount of silica fume.Keywords: differential scanning calorimetry, hydration, silica fume, thermogravimetry
Procedia PDF Downloads 231470 Reliability Assessment Using Full Probabilistic Modelling for Carbonation and Chloride Exposures, Including Initiation and Propagation Periods
Authors: Frank Papworth, Inam Khan
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Fib’s model code 2020 has four approaches for design life verification. Historically ‘deemed to satisfy provisions have been the principal approach, but this has limited options for materials and covers. The use of an equation in fib’s model code for service life design to predict time to corrosion initiation has become increasingly popular to justify further options, but in some cases, the analysis approaches are incorrect. Even when the equations are computed using full probabilistic analysis, there are common mistakes. This paper reviews the work of recent fib commissions on implementing the service life model to assess the reliability of durability designs, including initiation and propagation periods. The paper goes on to consider the assessment of deemed to satisfy requirements in national codes and considers the influence of various options, including different steel types, various cement systems, quality of concrete and cover, on reliability achieved. As modelling is based on achieving agreed target reliability, consideration is given to how a project might determine appropriate target reliability.Keywords: chlorides, marine, exposure, design life, reliability, modelling
Procedia PDF Downloads 224469 Effect of Reinforcement Steel Ratio on the Behavior of R. C. Columns Exposed to Fire
Authors: Hatem Ghith
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This research paper experimentally investigates the effect of burning by fire flame from one face on the behavior and load carrying capacity for reinforced columns. Residual ultimate load carrying capacity, axial deformation, crack pattern and maximum crack width for column specimens with and without burning were recorded and discussed. Tested six reinforced concrete columns were divided into control specimen and two groups. The first group was exposed to a fire with a different temperature (300, 500, 700 °C) for an hour with reinforcement ratio 0.89% and the second group was exposed to a fire with a temperature 500 °C for an hour with different reinforcement ratio (0.89%, 2.18%, and 3.57%), then all columns were tested under short-term axial loading. From the obtained results, it could be concluded that the fire parameters significantly influence the fire resistance of R.C columns. The fire parameters cause axial deformation and moment on the column due to the eccentricity that generated from the difference in temperature and consequently the compressive stresses of both faces of the columns but the increased reinforcement ratio enhanced the resistance of columns for axial deformation and moment on the column due to the eccentricity.Keywords: columns, reinforcement ratio, strength, time exposure
Procedia PDF Downloads 239468 Utilizing Quicklime (Calcium Oxide) for Self-Healing Properties in Innovation of Coconut Husk Fiber Bricks
Authors: Christian Gabriel Mariveles, Darelle Jay Gallardo, Leslie Dayaoen, Laurenz Paul Diaz
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True experimental research with descriptive analysis was conducted. Utilizing Quicklime (Calcium Oxide) for self-healing properties of coconut husk fibre concrete brick. There are 2 setups established: the first one has the 1:1:2 ratio of calcium oxide, cement and sand, and the second one has a 2:1:2 ratio of the same variables. The bricks are made from the residences along Barangay Greater Lagro. The mixture of sand and cement is mixed with coconut husk fibers and then molded with different ratios in the molder. After the drying of cement, the researchers tested the bricks in the laboratory for compressive strength. The brick with the highest PSI is picked by the researchers to drop into freefall testing, and it makes remarkable remarks as it is deformed after dropping to different heights with a maximum of 20 feet. Unfortunately, the self-healing capabilities were not observed during the 12 weeks of monitoring. However, the brick was weighed after 12 weeks of monitoring, and it increased in weight by 0.030 kg. from 1.833 kg. to 1.863 kg. meaning that this ratio 2 has the potential to self-heal, but 12 weeks of monitoring by the researchers is not enough to conclude that it has a significant difference.Keywords: self healing, coconut husk bricks, research, calcium oxide, utilizing quicklime
Procedia PDF Downloads 37467 Differential Terrain: A Spectrum in Capitalism Transformation
Authors: Sibo Lu, Zhongkai Qian
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This study endeavors to articulate a spectrum of capitalist transformation from a politico-economic perspective, categorizing the development of capitalism into pre-modern, modern, and post-modern stages while examining the transitions between these states. It critically engages with the concepts of pre-modernity, modernity, and post-modernity, typically aligned with cultural studies, to shed light on their objective changes in the politico-economic realm. Post-modernity, in this context, is associated with the transition to high-value-added services and economic growth in ‘developed’ countries amidst globalization, framing a ‘neoliberal’ economic transformation. The paper scrutinizes the neoliberal economic shifts in the latter half of the 20th century as part of the post-modern state, arguing against viewing post-modernity merely as a cultural or subjective interpretative stance. Instead, it is posited as a concrete politico-economic phase marked by the dominance of post-Fordist systems. Through integrating insights from the political economy with continental philosophy, this research provides a nuanced analysis of capitalism's evolution, challenging conventional class analyses under the capitalist system and fostering a broader understanding of socio-economic paradigms.Keywords: post marxism, critical theory, political economy, capitalism transformation
Procedia PDF Downloads 26466 Understanding the Role of Alkali-Free Accelerators in Wet-Mix Shotcrete
Authors: Ezgi Yurdakul, Klaus-Alexander Rieder, Richard Sibbick
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Most of the shotcrete projects require compliance with meeting a specified early-age strength target (e.g., reaching 1 MPa in 1 hour) that is selected based on the underground conditions. To meet the desired early-age performance characteristics, accelerators are commonly used as they increase early-age strength development rate and accelerate the setting thereby reducing sagging and rebound. The selection of accelerator type and its dosage is made by the setting time and strength required for the shotcrete application. While alkaline and alkali-free accelerators are the two main types used in wet-mix shotcrete; alkali-free admixtures increasingly substitute the alkaline accelerators to improve the performance and working safety. This paper aims to evaluate the impact of alkali-free accelerators in wet-mix on various tests including set time, early and later-age compressive strength, boiled absorption, and electrical resistivity. Furthermore, the comparison between accelerated and non-accelerated samples will be made to demonstrate the interaction between cement and accelerators. Scanning electron microscopy (SEM), fluorescent resin impregnated thin section and cut and polished surface images will be used to understand the microstructure characterization of mixes in the presence of accelerators.Keywords: accelerators, chemical admixtures, shotcrete, sprayed concrete
Procedia PDF Downloads 161465 Gender Mainstreaming in Kazakhstan: A University Audit as the First Stage to Inform Policy
Authors: A. S. CohenMiller, Jenifer Lewis, Gwen McEvoy, Kristy Kelly
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This international, interdisciplinary study presents the first stage of a gender mainstreaming project within one university as a microcosm of society in Kazakhstan to make concrete policy recommendations and set up the potential for new research to monitor change over time. Local, regional, and UN representatives have noted the critical need and interest in gender related issues in Kazakhstan. Gender mainstreaming has been noted as a strategy to understand and address gender equality and equity such as within the academy in exploring and examining organizational/management issues, university decision-making and leadership, assessing the overall academic climate, discrimination issues, hiring and promotion, and student recruitment and retention. This presentation provides preliminary findings from the university gender audit, highlighting key elements for moving forward in gender mainstreaming. The full study analyzes findings from the full gender audit including interview with key stakeholders, time-use surveys, participant-observations and interviews with female students, staff and faculty, and reviews of formal organizational policies and practices.Keywords: academia, equity, Eurasia, gender audit, gender mainstreaming, Kazakhstan, policy, time-use survey
Procedia PDF Downloads 391464 Structural Health Monitoring of Buildings and Infrastructure
Authors: Mojtaba Valinejadshoubi, Ashutosh Bagchi, Osama Moselhi
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Structures such as buildings, bridges, dams, wind turbines etc. need to be maintained against various factors such as deterioration, excessive loads, environment, temperature, etc. Choosing an appropriate monitoring system is important for determining any critical damage to a structure and address that to avoid any adverse consequence. Structural Health Monitoring (SHM) has emerged as an effective technique to monitor the health of the structures. SHM refers to an ongoing structural performance assessment using different kinds of sensors attached to or embedded in the structures to evaluate their integrity and safety to help engineers decide on rehabilitation measures. Ability of SHM in identifying the location and severity of structural damages by considering any changes in characteristics of the structures such as their frequency, stiffness and mode shapes helps engineers to monitor the structures and take the most effective corrective actions to maintain their safety and extend their service life. The main objective of this study is to review the overall SHM process specifically determining the natural frequency of an instrumented simply-supported concrete beam using modal testing and finite element model updating.Keywords: structural health monitoring, natural frequency, modal analysis, finite element model updating
Procedia PDF Downloads 330463 Analysis of the Properties of Hydrophobised Heat-Insulating Mortar with Perlite
Authors: Danuta Barnat-Hunek
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The studies are devoted to assessing the effectiveness of hydrophobic and air entraining admixtures based on organ silicon compounds. Mortars with lightweight aggregate–perlite were the subjects of the investigation. The following laboratory tests were performed: density, open porosity, total porosity, absorptivity, capability to diffuse water vapour, compressive strength, flexural strength, frost resistance, sodium sulphate corrosion resistance and the thermal conductivity coefficient. The composition of the two mixtures of mortars was prepared: mortars without a hydrophobic admixture and mortars with cementitious waterproofing material. Surface hydrophobisation was produced on the mortars without a hydrophobic admixture using a methyl silicone resin, a water-based emulsion of methyl silicone resin in potassium hydroxide and alkyl-alkoxy-silane in organic solvents. The results of the effectiveness of hydrophobisation of mortars are the following: The highest absorption after 14 days of testing was shown by mortar without an agent (57.5%), while the lowest absorption was demonstrated by the mortar with methyl silicone resin (52.7%). After 14 days in water the hydrophobisation treatment of the samples proved to be ineffective. The hydrophobised mortars are characterized by an insignificant mass change due to freezing and thawing processes in the case of the methyl silicone resin – 1%, samples without hydrophobisation –5%. This agent efficiently protected the mortars against frost corrosion. The standard samples showed very good resistance to the pressure of sodium sulphate crystallization. Organosilicon compounds have a negative influence on the chemical resistance (weight loss about 7%). The mass loss of non-hydrophobic mortar was 2 times lower than mortar with the hydrophobic admixture. Hydrophobic and aeration admixtures significantly affect the thermal conductivity and the difference is mainly due to the difference in porosity of the compared materials. Hydrophobisation of the mortar mass slightly decreased the porosity of the mortar, and thus in an increase of 20% of its compressive strength. The admixture adversely affected the ability of the hydrophobic mortar – it achieved the opposite effect. As a result of hydrophobising the mass, the mortar samples decreased in density and had improved wettability. Poor protection of the mortar surface is probably due to the short time of saturating the sample in the preparation. The mortars were characterized by high porosity (65%) and water absorption (57.5%), so in order to achieve better efficiency, extending the time of hydrophobisation would be advisable. The highest efficiency was obtained for the surface hydrophobised with the methyl silicone resin.Keywords: hydrophobisation, mortars, salt crystallization, frost resistance
Procedia PDF Downloads 200462 Investigating the Behavior of Underground Structures in the Event of an Earthquake
Authors: Davoud Beheshtizadeh, Farzin Malekpour
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The progress of technology and producing new machinery have made a big change in excavation operations and construction of underground structures. The limitations of space and some other economic, politic and military considerations gained the attention of most developed and developing countries towards the construction of these structures for mine, military, and development objectives. Underground highways, tunnels, subways, oil reservoir resources, fuels, nuclear wastes burying reservoir and underground stores are increasingly developing and being used in these countries. The existence and habitability of the cities depend on these underground installations or in other words these vital arteries. Stopping the flow of water, gas leakage and explosion, collapsing of sewage paths, etc., resulting from the earthquake are among the factors that can severely harm the environment and increase the casualty. Lack of sewage network and complete stoppage of the flow of water in Bam (Iran) is a good example of this kind. In this paper, we investigate the effect of wave orientation on structures and deformation of them and the effect of faulting on underground structures, and then, we study resistance of reinforced concrete against earthquake, simulate two different samples, analyze the result and point out the importance of paying attention to underground installations.Keywords: underground structures, earthquake, underground installations, axial deformations
Procedia PDF Downloads 187461 Environmental Science: A Proposal for Constructing New Knowledge for Ecotourism Itineraries
Authors: Veruska C. Dutra, Mary L. G. S. Senna
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The principle of sustainability has been studied by different sciences with the purpose of formulating clear and concrete models. Much has been discussed about sustainability, and several points of view have been used to try to explain it; environmental science emerges from various environmental discourses that are willing to establish a new concept for understanding this complexity. This way, we focus on the activity of ecotourism as a way to integrate sustainable practices proposed by environmental science, and thus, make it possible to create a new perspective for eco-tourists and the managers of tourist destinations towards nature. The aim of this study was to suggest a direction for environmental awareness, based on environmental science, to change the eco-tourist's view of nature in ecotourism tours. The methodology used was based on a case study concerning the Jalapão State Park - JSP, located in the State of Tocantins, Northern Brazil. The study was based on discussions, theoretical studies, bibliographical research and on-site research. We have identified that to incite the tourists’ awareness, they need to visit nature to understand the environmental problems and promote actions for its preservation. We highlight in this study actions to drive their human perception through environmental science, so that the ecotourism itinerary tours to the JSP, promote a balance between the natural environment and the tourist, making them, in this way, environmental tourists.Keywords: science, environmental, ecoturism, Jalapão
Procedia PDF Downloads 326460 An Analysis of Instruction Checklist Based on Universal Design for Learning
Authors: Yong Wook Kim
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The purpose of this study is to develop an instruction analysis checklist applicable to inclusive setting based on the Universal Design for Learning Guideline 2.0. To do this, two self-validation reviews, two expert validity reviews, and two usability evaluations were conducted based on the Universal Design for Learning Guideline 2.0. After validation and usability evaluation, a total of 36 items consisting of 4 items for each instruction was developed. In all questions, examples are presented for the purpose of reinforcing concrete. All the items were judged by the 3-point scale. The observation results were provided through a radial chart allowing SWOT analysis of the universal design for learning of teachers. The developed checklist provides a description of the principles and guidelines in the checklist itself as it requires a thorough understanding by the observer of the universal design for learning through prior education. Based on the results of the study, the instruction criteria, the specificity of the criteria, the number of questions, and the method of arrangement were discussed. As a future research, this study proposed the characteristics of application of universal design for learning for each subject, the comparison with the observation results through the self-report teaching tool, and the continual revision and supplementation of the lecture checklist.Keywords: inclusion, universal design for learning, instruction analysis, instruction checklist
Procedia PDF Downloads 273459 Fuzzy Multi-Criteria Decision-Making Based on Ignatian Discernment Process
Authors: Pathinathan Theresanathan, Ajay Minj
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Ignatian Discernment Process (IDP) is an intense decision-making tool to decide on life-issues. Decisions are influenced by various factors outside of the decision maker and inclination within. This paper develops IDP in the context of Fuzzy Multi-criteria Decision Making (FMCDM) process. Extended VIKOR method is a decision-making method which encompasses even conflict situations and accommodates weightage to various issues. Various aspects of IDP, namely three ways of decision making and tactics of inner desires, are observed, analyzed and articulated within the frame work of fuzzy rules. The decision-making situations are broadly categorized into two types. The issues outside of the decision maker influence the person. The inner feeling also plays vital role in coming to a conclusion. IDP integrates both the categories using Extended VIKOR method. Case studies are carried out and analyzed with FMCDM process. Finally, IDP is verified with an illustrative case study and results are interpreted. A confused person who could not come to a conclusion is able to take decision on a concrete way of life through IDP. The proposed IDP model recommends an integrated and committed approach to value-based decision making.Keywords: AHP, FMCDM, IDP, ignatian discernment, MCDM, VIKOR
Procedia PDF Downloads 246458 Role of Sodium Concentration, Waiting Time and Constituents’ Temperature on the Rheological Behavior of Alkali Activated Slag Concrete
Authors: Muhammet M. Erdem, Erdoğan Özbay, Ibrahim H. Durmuş, Mustafa Erdemir, Murat Bikçe, Müzeyyen Balçıkanlı
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In this paper, rheological behavior of alkali activated slag concretes were investigated depending on the sodium concentration (SC), waiting time (WT) after production, and constituents’ temperature (CT) parameters. For this purpose, an experimental program was conducted with four different SCs of 1.85, 3.0, 4.15, and 5.30%, three different WT of 0 (just after production), 15, and 30 minutes and three different CT of 18, 30, and 40 °C. Solid precursors are activated by water glass and sodium hydroxide solutions with silicate modulus (Ms = SiO2/Na2O) of 1. Slag content and (water + activator solution)/slag ratio were kept constant in all mixtures. Yield stress and plastic viscosity values were defined for each mixture by using the ICAR rheometer. Test results were demonstrated that all of the three studied parameters have tremendous effect on the yield stress and plastic viscosity values of the alkali activated slag concretes. Increasing the SC, WT, and CT drastically augmented the rheological parameters. At the 15 and 30 minutes WT after production, most of the alkali activated slag concretes were set instantaneously, and rheological measurements were not performed.Keywords: alkali activation, slag, rheology, yield stress, plastic viscosity
Procedia PDF Downloads 282457 Carbonation and Mechanical Performance of Reactive Magnesia Based Formulations
Authors: Cise Unluer
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Reactive MgO hydrates to form brucite (Mg(OH)2, magnesium hydroxide), which can then react with CO2 and additional water to form a range of strength providing hydrated magnesium carbonates (HMCs) within cement-based formulations. The presented work focuses on the use of reactive MgO in a range of concrete mixes, where it carbonates by absorbing CO2 and gains strength accordingly. The main goal involves maximizing the amount of CO2 absorbed within construction products, thereby reducing the overall environmental impact of the designed formulations. Microstructural analyses including scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetry/differential thermal analysis (TG/DTA) are used in addition to porosity, permeability and unconfined compressive strength (UCS) testing to understand the performance mechanisms. XRD Reference Intensity Ratio (RIR), acid digestion and TG/DTA are utilized to quantify the amount of CO2 sequestered, with the goal of achieving 100% carbonation through careful mix design, leading to a range of carbon neutral products with high strengths. As a result, samples stronger than those containing Portland cement (PC) were produced, revealing the link between the mechanical performance and microstructural development of the developed formulations with the amount of CO2 sequestered.Keywords: carbonation, compressive strength, reactive MgO cement, sustainability
Procedia PDF Downloads 169456 Comparative Sulphate Resistance of Pozzolanic Cement Mortars
Authors: Mahmud Abba Tahir
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This is report on experiment out to compare the sulphate resistance of sand mortar made with five different pozzolanic cement. The pozzolanic cement were prepared by blending powered burnt bricks from the Adamawa, Makurdi, Kano, Kaduna and Niger bricks factories with ordinary Portland cement in the ratio 1:4. Sand –pozzolanic cement mortars of mix ratio 1:6 and 1:3 with water-cement ratio of 0.65 and 0.40 respectively were used to prepare cubes and bars specimens. 150 mortar cubes of size 70mm x 70mm x 70mm and 35 mortar bars of 15mm x 15mm x 100mm dimensions were cast and cured for 28 days. The cured specimens then immersed in the solutions of K2SO4, (NH4)2SO4 and water for 28 days and then tested. The compressive strengths of cubes in water increased by 34% while those in the sulphate solutions decreased. Strength decreases of the cubes, cracking and warping of bars immersed in K2SO4 were less than those in (NH4)2SO4. Specimens made with Niger and Makurdi pulverized burnt bricks experienced less effect of the sulphates and can therefore be used as pozzolan in mortar and concrete to resist sulphate.Keywords: burnt bricks powder, comparative, pozzolanic cement, sulphates
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