Search results for: preplaced aggregate concrete
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2163

Search results for: preplaced aggregate concrete

543 Production of Cement-Free Construction Materials via Fly Ash Carbonation

Authors: Zhenhua Wei, Gabriel Falzone, Bu Wang, Laurent Pilon, Gaurav Sant

Abstract:

The production of ordinary Portland cement (OPC) is a CO₂ intensive process. Specifically, cement clinkering reactions require not only substantial energy in the form of heat, but also result in the release of CO₂, from limestone decarbonation and the combustion of fuel. To overcome this CO₂ intensive process, clinkering-free cementation is demonstrated by the carbonation of fly ash; i.e., a by-product of coal combustion. It is shown that in moist environments and at sub-boiling temperatures, calcium-rich fly ashes readily react with gas-phase CO₂ to provide cementation. After seven days of CO₂ exposure at 75°C, such formulations achieve a compressive strength on the order of 35 MPa and take-up 9% CO₂ (by mass of the solid). On the other hand, calcium-deficient fly ashes, due to their lack of alkalinity (i.e., abundance of mobile Ca or Mg), show little if any potential for CO₂ uptake and strength gain. The role of the CO₂ concentration and processing temperature are discussed and linked to the progress of reactions, and the development of microstructure. The outcomes demonstrate a means for enabling clinkering-free cementation while enabling beneficial utilization of CO₂ and fly ash; i.e., two abundant but underutilized industrial by-products.

Keywords: fly ash, carbonation, concrete, strength

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542 Present Status, Driving Forces and Pattern Optimization of Territory in Hubei Province, China

Authors: Tingke Wu, Man Yuan

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“National Territorial Planning (2016-2030)” was issued by the State Council of China in 2017. As an important initiative of putting it into effect, territorial planning at provincial level makes overall arrangement of territorial development, resources and environment protection, comprehensive renovation and security system construction. Hubei province, as the pivot of the “Rise of Central China” national strategy, is now confronted with great opportunities and challenges in territorial development, protection, and renovation. Territorial spatial pattern experiences long time evolution, influenced by multiple internal and external driving forces. It is not clear what are the main causes of its formation and what are effective ways of optimizing it. By analyzing land use data in 2016, this paper reveals present status of territory in Hubei. Combined with economic and social data and construction information, driving forces of territorial spatial pattern are then analyzed. Research demonstrates that the three types of territorial space aggregate distinctively. The four aspects of driving forces include natural background which sets the stage for main functions, population and economic factors which generate agglomeration effect, transportation infrastructure construction which leads to axial expansion and significant provincial strategies which encourage the established path. On this basis, targeted strategies for optimizing territory spatial pattern are then put forward. Hierarchical protection pattern should be established based on development intensity control as respect for nature. By optimizing the layout of population and industry and improving the transportation network, polycentric network-based development pattern could be established. These findings provide basis for Hubei Territorial Planning, and reference for future territorial planning in other provinces.

Keywords: driving forces, Hubei, optimizing strategies, spatial pattern, territory

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541 Investigate the Performance of SMA-FRP Composite Bars in Seismic Regions under Corrosion Conditions

Authors: Amirmozafar Benshams, Saman Shafeinejad, Mohammad Zaman Kabir, Farzad Hatami, Mohammadreza Khedmati, Mesbah Saybani

Abstract:

Steel bars has been used in concrete structures for more than one hundred years but lack of corrosion resistance of steel reinforcement has resulted in many structural failures. Fiber Reinforced Polymer (FRP) bar is an acceptable solution to replace steel to mitigate corrosion problem. Since FRP is a brittle material its use in seismic region has been a concern. FRP RC structures can be made ductile by employing a ductile material such as Shape Memory Alloy (SMA) at the plastic hinge region and FRP at the other regions on the other hand SMA is highly resistant to corrosion. Shape Memory Alloy has the unique ability to undergo large inelastic deformation and regain its initial shape through stress removal therefore utilizing composite SMA-FRP bars not only have good corrosion resistance but also have good performance in seismic region. The result show indicate that such composite SMA-FRP bars can substantially reduce the residual drift with adequate energy dissipation capacity during earthquake.

Keywords: steel bar, shape memory alloy, FRP, corrosion

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540 The Review for Repair of Masonry Structures Using the Crack Stitching Technique

Authors: Sandile Daniel Ngidi

Abstract:

Masonry structures often crack due to different factors, which include differential movement of structures, thermal expansion, and seismic waves. Retrofitting is introduced to ensure that these cracks do not expand to a point of making the wall fail. Crack stitching is one of many repairing methods used to repair cracked masonry walls. It is done by stitching helical stainless steel reinforcement bars to reconnect and stabilize the wall. The basic element of this reinforcing system is the mechanical interlink between the helical stainless-steel bar and the grout, which makes it such a flexible and well-known masonry repair system. The objective of this review was to use previous experimental work done by different authors to check the efficiency and effectiveness of using the crack stitching technique to repair and stabilize masonry walls. The technique was found to be effective to rejuvenate the strength of a masonry structure to be stronger than initial strength. Different factors were investigated, which include economic features, sustainability, buildability, and suitability of this technique for application in developing communities.

Keywords: brickforce, crack-stitching, masonry concrete, reinforcement, wall panels

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539 A Study of Evolutional Control Systems

Authors: Ti-Jun Xiao, Zhe Xu

Abstract:

Controllability is one of the fundamental issues in control systems. In this paper, we study the controllability of second order evolutional control systems in Hilbert spaces with memory and boundary controls, which model dynamic behaviors of some viscoelastic materials. Transferring the control problem into a moment problem and showing the Riesz property of a family of functions related to Cauchy problems for some integrodifferential equations, we obtain a general boundary controllability theorem for these second order evolutional control systems. This controllability theorem is applicable to various concrete 1D viscoelastic systems and recovers some previous related results. It is worth noting that Riesz sequences can be used for numerical computations of the control functions and the identification of new Riesz sequence is of independent interest for the basis-function theory. Moreover, using the Riesz sequences, we obtain the existence and uniqueness of (weak) solutions to these second order evolutional control systems in Hilbert spaces. Finally, we derive the exact boundary controllability of a viscoelastic beam equation, as an application of our abstract theorem.

Keywords: evolutional control system, controllability, boundary control, existence and uniqueness

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538 Manufacturing Process of Rubber Cement Composite Paver Block

Authors: Ratnadip Natwarbhai Bhoi

Abstract:

The objective of this research paper is to study waste tire crumb rubber granules as a partial concrete replacement by the different percentages of facing layer thickness and without facing layer in the production of rubber cement composite paver block. The physical properties of RCCRP compressive strength, flexural strength, abrasion strength density, and water absorption testing by the IS 15658:2006 method. All these physical properties depend upon the ratio of crumb rubber uses. The result showed that the with facing layer at 15 mm, 25 mm, totally rubberized and without facing layer had little effect on compressive strength, flexural strength and abrasion resistance properties. Water absorption is also important for the service life of the product. The crumb rubber paver block also performed quite well in both compressive strength and abrasion resistance. The rubber cement composite rubber paver block is suitable for nonstructural purposes, such as being lightweight and easy installation for the walkway, sidewalks, and playing area applications.

Keywords: rubber cement, crumb rubber, composite, layer

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537 China Pakistan Economic Corridor: A Changing Mechanism in Pakistan

Authors: Komal Niazi, He Guoqiang

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This paper is focused on ‘CPEC (China Pakistan Economic Corridor) a changing mechanism in Pakistan’. China Pakistan Economic Corridor (CPEC) activity under OBOR (One Belt One Road (OBOR) CPEC is a piece of the bigger umbrella and goes for giving another hallway of exchange for China and Pakistan and is relied upon to profit the entire of South Asian area. But this study reveals that significance of acculturation can never be overemphasized in the investigation of diverse impacts and the routes people groups of various ethnic personalities figure out how to adjust and acknowledge the social attributes of a larger part group in a multiethnic culture. This study also deals with the effects of acculturation which can be seen at multiple levels through CPEC for both Pakistani and Chinese people, who were working on this project. China and Pakistan exchanged the cultural and social patterns with each other. Probably the most perceptible gathering level impacts of cultural assimilation regularly incorporate changes in sustenance (food), clothing, and language. At the individual level, the procedure of cultural assimilation alludes to the socialization procedure by which the Pakistani local people and Chinese who were working in Pakistan adopted values, traditions, attitudes, states of mind, and practices. But China has imposed discourse through economic power and language. CPEC dominates Pakistan’s poor area’s and changes their living, social and cultural values. People also claimed this acculturation was a great threat to their cultural values and religious beliefs. Main findings of the study clearly ascertained that research was to find out the conceptual understanding of people about the acculturation process through CPEC. At the cultural level, aggregate activities and social organizations end up plainly adjusted, and at the behavioral level, there are changes in a person's day by day behavioral collection and some of the time in experienced anxiety. Anthropological data methods were used to collect data, like snowball and judgmental sampling, case studied methods.

Keywords: CPEC, acculturation process, language discourse, social norms, cultural values, religious beliefs

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536 Evaluating the Challenges of Large Scale Urban Redevelopment Projects for Central Government Employee Housing in Delhi

Authors: Parul Kapoor, Dheeraj Bhardwaj

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Delhi and other Indian cities accommodate thousands of Central Government employees in housing complexes called ‘General Pool Residential Accommodation’ (GPRA), located in prime parcels of the city. These residential colonies are now undergoing redevelopment at a massive scale, significantly impacting the ecology of the surrounding areas. Essentially, these colonies were low-rise, low-density planned developments with a dense tree cover and minimal parking requirements. But with increasing urbanisation and spike in parking demand, the proposed built form is an aggregate of high-rise gated complexes, redefining the skyline of the city which is a huge departure from the mediocre setup of Low-rise Walk-up apartments. The complexity of these developments is further aggravated by the need for parking which necessitates cutting huge number of trees to accommodate multiple layers of parking beneath the structures thus sidelining the authentic character of these areas which is laden with a dense tree cover. The aftermath of this whole process is the generation of a huge carbon footprint on the surrounding areas, which is unaccounted for, in the planning and design practice. These developments are currently planned as mix-use compounds with large commercial built-up spaces which have additional parking requirements over and above the residential parking. Also, they are perceived as gated complexes and not as neighborhood units, thus project isolated images of high-rise, dense systems with little context to the surroundings. The paper would analyze case studies of GPRA Redevelopment projects in Delhi, and the lack of relevant development control regulations which have led to abnormalities and complications in the entire redevelopment process. It would also suggest policy guidelines which can establish comprehensive codes for effective planning of these settlements.

Keywords: gated complexes, GPRA Redevelopment projects, increased densities, huge carbon footprint, mixed-use development

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535 Estimation of Snow and Ice Melt Contributions to Discharge from the Glacierized Hunza River Basin, Karakoram, Pakistan

Authors: Syed Hammad Ali, Rijan Bhakta Kayastha, Danial Hashmi, Richard Armstrong, Ahuti Shrestha, Iram Bano, Javed Hassan

Abstract:

This paper presents the results of a semi-distributed modified positive degree-day model (MPDDM) for estimating snow and ice melt contributions to discharge from the glacierized Hunza River basin, Pakistan. The model uses daily temperature data, daily precipitation data, and positive degree day factors for snow and ice melt. The model is calibrated for the period 1995-2001 and validated for 2002-2013, and demonstrates close agreements between observed and simulated discharge with Nash–Sutcliffe Efficiencies of 0.90 and 0.88, respectively. Furthermore, the Weather Research and Forecasting model projected temperature, and precipitation data from 2016-2050 are used for representative concentration pathways RCP4.5 and RCP8.5, and bias correction was done using a statistical approach for future discharge estimation. No drastic changes in future discharge are predicted for the emissions scenarios. The aggregate snow-ice melt contribution is 39% of total discharge in the period 1993-2013. Snow-ice melt contribution ranges from 35% to 63% during the high flow period (May to October), which constitutes 89% of annual discharge; in the low flow period (November to April) it ranges from 0.02% to 17%, which constitutes 11 % of the annual discharge. The snow-ice melt contribution to total discharge will increase gradually in the future and reach up to 45% in 2041-2050. From a sensitivity analysis, it is found that the combination of a 2°C temperature rise and 20% increase in precipitation shows a 10% increase in discharge. The study allows us to evaluate the impact of climate change in such basins and is also useful for the future prediction of discharge to define hydropower potential, inform other water resource management in the area, to understand future changes in snow-ice melt contribution to discharge, and offer a possible evaluation of future water quantity and availability.

Keywords: climate variability, future discharge projection, positive degree day, regional climate model, water resource management

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534 Moment-Curvature Relation for Nonlinear Analysis of Slender Structural Walls

Authors: E. Dehghan, R. Dehghan

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Generally, the slender structural walls have flexural behavior. Since behavior of bending members can be explained by moment–curvature relation, therefore, an analytical model is proposed based on moment–curvature relation for slender structural walls. The moment–curvature relationships of RC sections are constructed through section analysis. Governing equations describing the bond-slip behavior in walls are derived and applied to moment–curvature relations. For the purpose of removing the imprecision in analytical results, the plastic hinge length is included in the finite element modeling. Finally, correlation studies between analytical and experimental results are conducted with the objective to establish the validity of the proposed algorithms. The results show that bond-slip effect is more significant in walls subjected to larger axial compression load. Moreover, preferable results are obtained when ultimate strain of concrete is assumed conservatively.

Keywords: nonlinear analysis, slender structural walls, moment-curvature relation, bond-slip, plastic hinge length

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533 Studies and Full Scale Tests for the Development of a Ravine Filling with a Depth of about 12.00m

Authors: Dana Madalina Pohrib, Elena Irina Ciobanu

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In compaction works, the most often used codes and standards are those for road embankments and refer to a maximum filling height of 3.00m. When filling a height greater than 3.00m, such codes are no longer valid and thus their application may lead to technical difficulties in the process of compaction and to the achievement of a sufficient degree of compaction. For this reason, in the case of controlled fillings with heights greater than 3.00m it is necessary to formulate and apply a number of special techniques, which can be determined by performing a full scale test. This paper presents the results of the studies and full scale tests conducted for the stabilization of a ravine with vertical banks and a depth of about 12.00m. The fillings will support a heavy traffic road connecting the two parts of a village in Vaslui County, Romania. After analyzing two comparative intervention solutions, the variant of a controlled filling bordered by a monolith concrete retaining wall was chosen. The results obtained by the authors highlighted the need to insert a geogrid reinforcement at every 2.00m for creating a 12.00m thick compacted fill.

Keywords: compaction, dynamic probing, stability, soil stratification

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532 The Effect of Nanoclay on Long Term Performance of Asphalt Concrete Pavement

Authors: A. Khodadadi, Hasani, Salehi

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The advantages of using modified asphalt binders are widely recognized—primarily, improved rutting resistance, reduced fatigue cracking and less cold-temperature cracking. Nanoclays are known to enhance the properties of many polymers. Nanoclays are used to improve modulus and tensile strength, flame resistance and thermal and structural properties of many materials. This paper intends to investigate the application and development of nano-technological concepts for bituminous materials and asphalt pavements. The application of nano clay on the fatigue life of asphalt pavement have not been yet thoroughly understood. In this research, two type of highway asphalt materials, dense Marshall specimens, with 2% nano clay and without nano clay, were employed for the fatigue behavior of the asphalt pavement.The effect of nano additive on the performance of flexible pavements has been investigated through the indirect tensile test for the samples prepared with 2% nano clay and without nano clay in four stress levels from 200–500 kPa. The primary results indicated samples with 2% nano clay have almost double or even more fatigue life in most of stress levels.

Keywords: Nano clay, Asphalt, fatigue life, pavement

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531 The Comparison Study of Human Microbiome in Chronic Rhinosinusitis between Adults and Children

Authors: Il Ho Park, Joong Seob Lee, Sung Hun Kang, Jae-Min Shin, Il Seok Park, Seok Min Hong, Seok Jin Hong

Abstract:

Introduction: The human microbiota is the aggregate of microorganisms, and the bacterial microbiome of the human digestive tract contributes to both health and disease. In health, bacteria are key components in the development of mucosal barrier function and in innate and adaptive immune responses, and they also work to suppress the establishment of pathogens. In human upper airway, the sinonasal microbiota might play an important role in chronic rhinosinusitis (CRS). The purpose of this study is to investigate the human upper airway microbiome in CRS patients and to compare the sinonasal microbiome of adults with children. Materials and methods: A total of 19 samples from 19 patients (Group1; 9 CRS in children, aged 5 to 14 years versus Group 2; 10 CRS in adults aged 21 to 59 years) were examined. Swabs were collected from the middle meatus and/or anterior ethmoid region under general anesthesia during endoscopic sinus surgery or tonsillectomy. After DNA extraction from swab samples, we analysed bacterial microbiome consortia using 16s rRNA gene sequencing approach (the Illumina MiSeq platform). Results: In this study, relatively abundance of the six bacterial phyla and tremendous genus and species found in substantial amounts in the individual sinus swab samples, include Corynebacterium, Hemophilus, Moraxella, and Streptococcus species. Anaerobes like Fusobacterium and Bacteroides were abundantly present in the children group, Bacteroides and Propionibacterium were present in adults group. In genus, Haemophilus was the most common CRS microbiome in children and Corynebacterium was the most common CRS microbiome in adults. Conclusions: Our results show the diversity of human upper airway microbiome, and the findings will suggest that CRS is a polymicrobial infection. The Corynebacterium and Hemophilus may live as commensals on mucosal surfaces of sinus in the upper respiratory tract. The further study will be needed for analysis of microbiome-human interactions in upper airway and CRS.

Keywords: microbiome, upper airway, chronic rhinosinusitis, adult and children

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530 Using Action Research to Digitize Theses and Journal Articles at the Main Library, Sultan Qaboos University, Oman

Authors: Nabhan H. N. Al-Harrasi

Abstract:

Action Research (AR) plays an important role in improving the problematical situation. It is a process that enhances thinking and practise and bridges the gap between abstract and concrete thinking. Nowadays, AR as a methodology is wildly used to implement projects based on understanding the needs of owners, considering the organizational culture, meeting the requirements, encouraging partnership, representing different viewpoints, and building the project. This research describes the whole processes of digitizing Post-graduate theses and all articles published in 6 Journals at Sultan Qaboos University. AR implemented to respond to the university needs to enhance accessibilities to its information resources and make them available through the national repository. In order to prepare the action plan, the library administration met to discuss several points related to the proposed project, the most important of which are: • Providing digitalization devices. • Locating a specific part of the Library as a Digitization Unit. • Choosing a team. • Defining tasks. • Implementing the proposed project and evaluating the whole processes.

Keywords: action research, digitization, Theses, Journal articles, open access, Oman

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529 Detection of Phoneme [S] Mispronounciation for Sigmatism Diagnosis in Adults

Authors: Michal Krecichwost, Zauzanna Miodonska, Pawel Badura

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The diagnosis of sigmatism is mostly based on the observation of articulatory organs. It is, however, not always possible to precisely observe the vocal apparatus, in particular in the oral cavity of the patient. Speech processing can allow to objectify the therapy and simplify the verification of its progress. In the described study the methodology for classification of incorrectly pronounced phoneme [s] is proposed. The recordings come from adults. They were registered with the speech recorder at the sampling rate of 44.1 kHz and the resolution of 16 bit. The database of pathological and normative speech has been collected for the study including reference assessments provided by the speech therapy experts. Ten adult subjects were asked to simulate a certain type of stigmatism under the speech therapy expert supervision. In the recordings, the analyzed phone [s] was surrounded by vowels, viz: ASA, ESE, ISI, SPA, USU, YSY. Thirteen MFCC (mel-frequency cepstral coefficients) and RMS (root mean square) values are calculated within each frame being a part of the analyzed phoneme. Additionally, 3 fricative formants along with corresponding amplitudes are determined for the entire segment. In order to aggregate the information within the segment, the average value of each MFCC coefficient is calculated. All features of other types are aggregated by means of their 75th percentile. The proposed method of features aggregation reduces the size of the feature vector used in the classification. Binary SVM (support vector machine) classifier is employed at the phoneme recognition stage. The first group consists of pathological phones, while the other of the normative ones. The proposed feature vector yields classification sensitivity and specificity measures above 90% level in case of individual logo phones. The employment of a fricative formants-based information improves the sole-MFCC classification results average of 5 percentage points. The study shows that the employment of specific parameters for the selected phones improves the efficiency of pathology detection referred to the traditional methods of speech signal parameterization.

Keywords: computer-aided pronunciation evaluation, sibilants, sigmatism diagnosis, speech processing

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528 Realization of Wearable Inertial Measurement Units-Sensor-Fusion Harness to Control Therapeutic Smartphone Applications

Authors: Svilen Dimitrov, Manthan Pancholi, Norbert Schmitz, Didier Stricker

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This paper presents the end-to-end development of a wearable motion sensing harness consisting of computational unit and four inertial measurement units to control three smartphone therapeutic games for children. The inertial data is processed in real time to obtain lower body motion information like knee raises, feet taps and squads. By providing a Wi-Fi connection interface the sensor harness acts wireless remote control for smartphone applications. By performing various lower body movements the users provoke corresponding game state changes. In contrary to the current similar offers, like Nintendo Wii Remote, Xbox Kinect and Playstation Move, this product, consisting of the sensor harness and the applications on top of it, are fully wearable, which means they do not rely on the user to be bound to concrete soft- or hardwareequipped space.

Keywords: wearable harness, inertial measurement units, smartphone therapeutic games, motion tracking, lower-body activity monitoring

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527 Low-Level Forced and Ambient Vibration Tests on URM Building Strengthened by Dampers

Authors: Rafik Taleb, Farid Bouriche, Mehdi Boukri, Fouad Kehila

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The aim of the paper is to investigate the dynamic behavior of an unreinforced masonry (URM) building strengthened by DC-90 dampers by ambient and low-level forced vibration tests. Ambient and forced vibration techniques are usually applied to reinforced concrete or steel buildings to understand and identify their dynamic behavior, however, less is known about their applicability for masonry buildings. Ambient vibrations were measured before and after strengthening of the URM building by DC-90 dampers system. For forced vibration test, a series of low amplitude steady state harmonic forced vibration tests were conducted after strengthening using eccentric mass shaker. The resonant frequency curves, mode shapes and damping coefficients as well as stress distribution in the steel braces of the DC-90 dampers have been investigated and could be defined. It was shown that the dynamic behavior of the masonry building, even if not regular and with deformable floors, can be effectively represented. It can be concluded that the strengthening of the building does not change the dynamic properties of the building due to the fact of low amplitude excitation which do not activate the dampers.

Keywords: ambient vibrations, masonry buildings, forced vibrations, structural dynamic identification

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526 Seismic Assessment of Old Existing RC Buildings with Masonry Infill in Madinah as Per ASCE

Authors: Tarek M. Alguhane, Ayman H. Khalil, Nour M. Fayed, Ayman M. Ismail

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An existing RC building in Madinah is seismically evaluated with and without infill wall. Four model systems have been considered i. e. model I (no infill), model IIA (strut infill-update from field test), model IIB (strut infill- ASCE/SEI 41) and model IIC (strut infill-Soft storey-ASCE/SEI 41). Three dimensional pushover analyses have been carried out using SAP 2000 software incorporating inelastic material behavior for concrete, steel and infill walls. Infill wall has been modeled as equivalent strut according to suggested equation matching field test measurements and to the ASCE/SEI 41 equation. The effect of building modeling on the performance point as well as capacity and demand spectra due to EQ design spectrum function in Madinah area has been investigated. The response modification factor (R) for the 5 story RC building is evaluated from capacity and demand spectra (ATC-40) for the studied models. The results are summarized and discussed.

Keywords: infill wall, pushover analysis, response modification factor, seismic assessment

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525 Optimal Design of Friction Dampers for Seismic Retrofit of a Moment Frame

Authors: Hyungoo Kang, Jinkoo Kim

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This study investigated the determination of the optimal location and friction force of friction dampers to effectively reduce the seismic response of a reinforced concrete structure designed without considering seismic load. To this end, the genetic algorithm process was applied and the results were compared with those obtained by simplified methods such as distribution of dampers based on the story shear or the inter-story drift ratio. The seismic performance of the model structure with optimally positioned friction dampers was evaluated by nonlinear static and dynamic analyses. The analysis results showed that compared with the system without friction dampers, the maximum roof displacement and the inter-story drift ratio were reduced by about 30% and 40%, respectively. After installation of the dampers about 70% of the earthquake input energy was dissipated by the dampers and the energy dissipated in the structural elements was reduced by about 50%. In comparison with the simplified methods of installation, the genetic algorithm provided more efficient solutions for seismic retrofit of the model structure.

Keywords: friction dampers, genetic algorithm, optimal design, RC buildings

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524 Seismic Behaviour of CFST-RC Columns

Authors: Raghabendra Yadav, Baochun Chen, Huihui Yuan, Zhibin Lian

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Concrete Filled Steel Tube (CFST) columns are widely used in Civil Engineering Structures due to their abundant properties. CFST-RC column is a built up column in which CFST members are connected with RC web. The CFST-RC column has excellent static and earthquake resistant properties, such as high strength, high ductility and large energy absorption capacity. CFST-RC columns have been adopted as piers in Ganhaizi Bridge in high seismic risk zone with a highest pier of 107m. The experimental investigation on scaled models of similar type of the CFST-RC pier are carried out. The experimental investigation on scaled models of similar type of the CFST-RC pier are carried out. Under cyclic loading, the hysteretic performance of CFST-RC columns, such as failure modes, ductility, load displacement hysteretic curves, energy absorption capacity, strength and stiffness degradation are studied in this paper.

Keywords: CFST, cyclic load, Ganhaizi bridge, seismic performance

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523 Experimental Study of the Infill Masonry Walls Response Subjected to Out-Of-Plane Static Loadings

Authors: André Furtado, Hugo Rodrigues, António Arêde, Humberto Varum

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Besides characterized as non-structural elements, infill masonry (IM) walls have an important contribute in the structural response of reinforced concrete structures as proved by the damages observed recent earthquakes. In particular, the out-of-plane (OOP) collapse has been one of the most observed failure mechanism. The aim of this research is to contribute to the increase of understanding regarding the OOP behaviour of full-scale infill panels considering different variables such as panel support width and axial load on the top of columns. For this, it was carried out in the Laboratory of Earthquake and Structural Engineering (LESE) an experimental campaign of five full-scale IM walls subjected to OOP distributed cyclic loadings. Specimens with different variables such as previous in-plane damage, support conditions, axial load on the top of the columns were studied. The results will be presented and discussed along the manuscript in terms of force-displacement hysteretic curves, cracking pattern, initial stiffness, stiffness degradation and accumulative energy dissipation.

Keywords: infill masonry walls, experimental testing, out-of-plane, full-scale

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522 Significance of Preservation of Cultural Resources: A Case of Walled City of Lahore as a Micro-Destination

Authors: Menaahyl Seraj, Gokce Ozdemir

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Tourism at destinations is dependent on various resources such as archeology and architecture. The need to preserve those resources is of the utmost importance when long-term tourism development is aimed. Shahi Guzargah (Royal Trail) was subject to a preservation project that is a linear historical passage within the Walled City of Lahore. Even though Lahore with its congested streets, lacks proper infrastructure and economically weak but yet it has the potential of transforming it into a tourist destination. This study highlights the potential hidden in the preservation of cultural resources through proper and concrete planning of living heritage city, and how it improves socio-economic standards of the community and affects tourism. Semi-structured open-ended interview question-forms were used to collect qualitative data from 14 respective stakeholders of the walled city and 10 concerned officials. The results of the study show that the preservation of cultural resources impacts and accelerates positively the development process of a destination. All opinions and gathered information reflect the importance of cultural preservation and its effect on increasing tourism.

Keywords: cultural tourism, cultural resources, destination, preservation

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521 Evaluation of Structural Behavior of Wide Sleepers on Asphalt Trackbed Due to Embedded Shear Keys

Authors: Seong Hyeok Lee, Jin Wook Lee, Bu Seog Ju, Woo Young Jung

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Korea Train eXpress (KTX) is now being operated, which allows Korea being one of the countries that operates the high-speed rail system. The high-speed rail has its advantage of short time transportation of population and materials, which lead to many researches performed in this matter. In the case of high speed classical trackbed system, the maintenance and usability of gravel ballast system is costly. Recently, the concrete trackbed structure has been introduced as a replacement of classical trackbed system. In this case, the sleeper plays a critical role. Current study investigated to develop the track sleepers readily applicable to the top of the asphalt trackbed, as part of the trcakbed study utilizing the asphalt material. Among many possible shapes and design of sleepers, current study proposed two types of wide-sleepers according to the shear-key installation method. The structural behavior analysis and safety evaluation on each case was conducted using Korean design standard.

Keywords: wide sleepers, asphalt, high-speed railway, shear-key

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520 Mechanistic Study of Composite Pavement Behavior in Heavy Duty Area

Authors: Makara Rith, Young Kyu Kim, Seung Woo Lee

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In heavy duty areas, asphalt pavement constructed as entrance roadway may expose distresses such as cracking and rutting during service life. To mitigate these problems, composite pavement with a roller-compacted concrete base may be a good alternative; however, it should be initially investigated. Structural performances such as fatigue cracking and rut depth may be changed due to variation of some design factors. Therefore, this study focuses on the variation effect of material modulus, layer thickness and loading on composite pavement performances. Stress and strain at the critical location are determined and used as the input of transfer function for corresponding distresses to evaluate the pavement performance. Also, composite pavement satisfying the design criteria may be selected as a design section for heavy duty areas. Consequently, this investigation indicates that composite pavement has the ability to eliminate fatigue cracking in asphalt surfaces and significantly reduce rut depth. In addition, a thick or strong rigid base can significantly reduce rut depth and prolong fatigue life of this layer.

Keywords: composite pavement, ports, cracking, rutting

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519 Numerical Investigation for External Strengthening of Dapped-End Beams

Authors: A. Abdel-Moniem, H. Madkour, K. Farah, A. Abdullah

Abstract:

The reduction in dapped end beams depth nearby the supports tends to produce stress concentration and hence results in shear cracks, if it does not have an adequate reinforcement detailing. This study investigates numerically the efficiency of applying different external strengthening techniques to the dapped end of such beams. A two-dimensional finite element model was built to predict the structural behavior of dapped ends strengthened with different techniques. The techniques included external bonding of the steel angle at the re-entrant corner, un-bounded bolt anchoring, external steel plate jacketing, exterior carbon fiber wrapping and/or stripping and external inclined steel plates. The FE analysis results are then presented in terms of the ultimate load capacities, load-deflection and crack pattern at failure. The results showed that the FE model, at various stages, was found to be comparable to the available test data. Moreover, it enabled the capture of the failure progress, with acceptable accuracy, which is very difficult in a laboratory test.

Keywords: dapped-end beams, finite element, shear failure, strengthening techniques, reinforced concrete, numerical investigation

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518 What Defines Acceptable European Values for Georgia

Authors: Maia Kipiani, Tamari Beridze, Natalia Tchanturia, Bella Goderdzishvili, Sophio Beridze, Natia Kuparadze

Abstract:

Europe has concrete examples how small nations can survive and maintain their identity in its area. Values are eternal guides of our life and source of its perfection. European values are universal and relevant for every epoch, society or state. Values, such as personal freedom, human dignity, sovereignty of law, national or cultural identity are universal and eternal. Even superficial review of history of Georgian culture clearly shows that western values, including fundamental human rights. This paper discusses the approach and findings of choice of values in Georgia. Georgia is still quite far away from perfectly established values. Georgia has walked the hardest road till XXI century. Country survived miraculously many times. The study shows that the only way to survive is to strengthen national, traditional values and should not forget global factors. It is clear that for achievement of goals is important European education, legislative and economic reforms, peacefully and democratically develop Georgia.

Keywords: democracy, economical reforms, European values, human dignity, science, society, sovereignty of law, well-being

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517 Seismic Base Shear Force Depending on Building Fundamental Period and Site Conditions: Deterministic Formulation and Probabilistic Analysis

Authors: S. Dorbani, M. Badaoui, D. Benouar

Abstract:

The aim of this paper is to investigate the effect of the building fundamental period of reinforced concrete buildings of (6, 9, and 12-storey), with different floor plans: Symmetric, mono-symmetric, and unsymmetric. These structures are erected at different epicentral distances. Using the Boumerdes, Algeria (2003) earthquake data, we focused primarily on the establishment of the deterministic formulation linking the base shear force to two parameters: The first one is the fundamental period that represents the numerical fingerprint of the structure, and the second one is the epicentral distance used to represent the impact of the earthquake on this force. In a second step, with a view to highlight the effect of uncertainty in these parameters on the analyzed response, these parameters are modeled as random variables with a log-normal distribution. The variability of the coefficients of variation of the chosen uncertain parameters, on the statistics on the seismic base shear force, showed that the effect of uncertainty on fundamental period on this force statistics is low compared to the epicentral distance uncertainty influence.

Keywords: base shear force, fundamental period, epicentral distance, uncertainty, lognormal variables, statistics

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516 A Fuzzy Structural Equation Model for Development of a Safety Performance Index Assessment Tool in Construction Sites

Authors: Murat Gunduz, Mustafa Ozdemir

Abstract:

In this research, a framework is to be proposed to model the safety performance in construction sites. Determinants of safety performance are to be defined through extensive literature review and a multidimensional safety performance model is to be developed. In this context, a questionnaire is to be administered to construction companies with sites. The collected data through questionnaires including linguistic terms are then to be defuzzified to get concrete numbers by using fuzzy set theory which provides strong and significant instruments for the measurement of ambiguities and provides the opportunity to meaningfully represent concepts expressed in the natural language. The validity of the proposed safety performance model, relationships between determinants of safety performance are to be analyzed using the structural equation modeling (SEM) which is a highly strong multi variable analysis technique that makes possible the evaluation of latent structures. After validation of the model, a safety performance index assessment tool is to be proposed by the help of software. The proposed safety performance assessment tool will be based on the empirically validated theoretical model.

Keywords: Fuzzy set theory, safety performance assessment, safety index, structural equation modeling (SEM), construction sites

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515 Machine Installation and Maintenance Management

Authors: Mohammed Benmostefa

Abstract:

In the industrial production of large series or even medium series, there are vibration problems. In continuous operations, technical devices result in vibrations in solid bodies and machine components, which generate solid noise and/or airborne noise. This is because vibrations are the mechanical oscillations of an object near its equilibrium point. In response to the problems resulting from these vibrations, a number of remedial acts and solutions have been put forward. These include insulation of machines, insulation of concrete masses, insulation under screeds, insulation of sensitive equipment, point insulation of machines, linear insulation of machines, full surface insulation of machines, and the like. Following this, the researcher sought not only to raise awareness on the possibility of lowering the vibration frequency in industrial machines but also to stress the significance of procedures involving the pre-installation process of machinery, namely, setting appropriate installation and start-up methods of the machine, allocating and updating imprint folders to each machine, and scheduling maintenance of each machine all year round to have reliable equipment, gain cost reduction and maintenance efficiency to eventually ensure the overall economic performance of the company.

Keywords: maintenance, vibration, efficiency, production, machinery

Procedia PDF Downloads 60
514 Frailty Patterns in the US and Implications for Long-Term Care

Authors: Joelle Fong

Abstract:

Older persons are at greatest risk of becoming frail. As survival to the age of 80 and beyond continues to increase, the health and frailty of older Americans has garnered much recent attention among policy makers and healthcare administrators. This paper examines patterns in old-age frailty within a multistate actuarial model that characterizes the stochastic process of biological ageing. Using aggregate population-level U.S. mortality data, we implement a stochastic aging model to examine cohort trends and gender differences in frailty distributions for older Americans born 1865 – 1894. The stochastic ageing model, which draws from the fields of actuarial science and gerontology, is well-established in the literature. The implications for public health insurance programs are also discussed. Our results suggest that, on average, women tend to be frailer than men at older ages and reveal useful insights about the magnitude of the male-female differential at critical age points. Specifically, we note that the frailty statuses of males and females are actually quite comparable from ages 65 to 80. Beyond age 80, however, the frailty levels start to diverge considerably implying that women are moving quicker into worse states of health than men. Tracking average frailty by gender over 30 successive birth cohorts, we also find that frailty levels for both genders follow a distinct peak-and-trough pattern. For instance, frailty among 85-year old American survivors increased in years 1954-1963, decreased in years 1964-1971, and again started to increase in years 1972-1979. A number of factors may have accounted for these cohort differences including differences in cohort life histories, differences in disease prevalence, differences in lifestyle and behavior, differential access to medical advances, as well as changes in environmental risk factors over time. We conclude with a discussion on the implications of our findings on spending for long-term care programs within the broader health insurance system.

Keywords: actuarial modeling, cohort analysis, frail elderly, health

Procedia PDF Downloads 225