Precast Concrete Paving Repairs at Vancouver International Airport

2021 ◽  
pp. 036119812110025
Author(s):  
Christopher T. Senseney ◽  
Peter J. Smith ◽  
Mark B. Snyder
Keyword(s):  
Load Transfer ◽  
Precast Concrete ◽  
Base Material ◽  
Pilot Project ◽  
Galvanized Steel ◽  
Slab Thickness ◽  
Foreign Object Damage ◽  
Design Procedures ◽  
International Airport ◽  
And Function

In 2019, Vancouver International Airport conducted a precast concrete panel replacement pilot project on Taxiway Victor to establish whether precast concrete was a viable option for a planned runway repair project. This was the first major use of precast airfield pavement in North America in nearly 20 years. Twelve panels measuring 6 m × 7.5 m with a thickness of 360 mm and weighing up to 43 metric tons each were installed to demonstrate the viability of in-situ concrete panel replacement in 8-h night work windows. The panels were designed as heavily reinforced “ductile slabs”; conventional pavement design procedures would have required much greater slab thickness and removal/replacement of base material, which would have greatly slowed panel replacements. Load transfer was provided by 38-mm diameter galvanized steel dowels, which were spaced nonuniformly along each panel edge. The use of bottom slots presented a clean surface with minimal potential for foreign object damage. Five of the panels included embedded airfield light cans, which required great placement precision to ensure their proper alignment and function. Seven of the panels were nonplanar, requiring a special first-of-its-kind warped casting bed that was large enough to produce nonplanar airfield-sized panels to the specified fabrication tolerances. Many valuable lessons were learned during this pilot project, which confirmed that long-life jointed precast concrete pavement repairs could be successfully constructed in 8-h overnight work windows on an active airfield using large repair panels and doweled joints, while adhering to strict panel-to-panel elevation tolerances.

scholarly journals Concrete Modular Pavements – Types, Issues And Challenges

2019 ◽  
Vol 14 (1) ◽  
pp. 80-103 ◽  
Author(s):  
Audrius Vaitkus ◽  
Judita Gražulytė ◽  
Rita Kleizienė ◽  
Viktoras Vorobjovas ◽  
Ovidijus Šernas
Keyword(s):  
Traffic Congestion ◽  
Road Network ◽  
Load Transfer ◽  
Precast Concrete ◽  
Concrete Slabs ◽  
Time Saving ◽  
Urban Streets ◽  
The Road ◽  
Different Types ◽  
Pavement Construction

According to the European Asphalt Pavement Association, more than 90 per cent of the European road network is paved with asphalt. Constantly increasing traffic volume and climate change accelerate deterioration of current pavements. As a result, there arises a need to rehabilitate them prematurely. Repair and rehabilitation work lead to traffic congestion, which is one of the most significant concerns in highly trafficked roads and urban streets. Concrete modular pavements consisting of precast concrete slabs are a reasonable solution to deal with the road works since their construction, as well as repair, is time-saving. Repair works typically are implemented during a low traffic period (usually at night). A primary purpose of concrete modular pavements is heavily trafficked roads and other transport areas. This paper focuses on concrete modular pavements, their types, issues and challenges related to their design, slab fabrication and pavement construction. The conducted analysis revealed 15 different types of concrete modular pavements that differ from the techniques of slab joints and load transfer between the adjacent slabs. More than 20 issues and challenges related to the design of modular elements, slab fabrication and pavement construction were identified. Finally, the existing practice of concrete modular pavements was summarised and the gaps of scientific knowledge, as well as a need for comprehensive research, were defined.

Experimental Investigations on the Seismic Behavior of Precast Concrete Columns with Novel Box Connections

2019 ◽  
Vol 14 (02) ◽  
pp. 2050007
Author(s):  
Xizhi Zhang ◽  
Shengbo Xu ◽  
Shaohua Zhang ◽  
Gaodong Xu
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Seismic Behavior ◽  
Load Transfer ◽  
Precast Concrete ◽  
Hysteretic Behavior ◽  
Experimental Investigations ◽  
Test Results ◽  
Energy Dissipation Capacity

In this study, two types of novel box connections were developed to connect precast concrete (PC) columns and to ensure load transfer integrity. Cyclic loading tests were conducted to investigate the seismic behavior of the PC columns with proposed connections as well as the feasibility and reliability of novel box connections. The failure mode, hysteretic behavior, bearing capacity, ductility, stiffness degradation and energy dissipation were obtained and discussed. The test results indicated that the all PC columns exhibited the ductile flexural failure mode and that the proposed connections could transfer the force effectively. The adoption of novel box connections could improve the deformation capacity and energy dissipation capacity of PC columns. A higher axial compression ratio could enhance the bearing capacity of PC column with proposed connection but would significantly deteriorate the ductility and energy dissipation capacity. Finite element models were developed and the feasibility of the models was verified by the comparison with the test results.

Precast Concrete Soldier Pile System with Corrugated Section Post for Riverbank Protection

2014 ◽  
Vol 567 ◽  
pp. 457-462
Author(s):  
Nur Akmilah ◽  
Ong Chong Yong
Keyword(s):  
Precast Concrete ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Pilot Project ◽  
Structural Shape ◽  
Structural Capacity ◽  
Wall Structures ◽  
Innovative Solution ◽  
Stone Walls ◽  
Soldier Pile

Gabions, rubble stone walls, L-shape concrete retaining wall and revetments are commonly used for riverbank protection against base scouring and soil slope erosion. These conventional solutions for low retaining wall structures are relatively cheap and easy to execute. However, they are proven not lasting with high maintenance costs. Although steel sheetpile walls are structures with better performance for slope stabilization purpose, they are very expensive to build and maintain against corrosion. To address the problem, a new precast concrete soldier pile wall system was developed to provide a permanent and relatively economical solution with several innovative features. The system is comprised of a series of precast posts driven to the predetermined depth and secondary precast lagging elements secured between posts to support the retained earths. The structural capacity that resists lateral load is derived from passive earth pressure mobilized in front the embedded body to toe of the posts. The lagging elements are installed at 0.5m to 1.0m below the river invert levels to provide protection against base scouring. The precast posts and laggings take the efficient structural shape of corrugated section. They are jointed with a specially designed tongue and groove (T&G) slots to facilitate installation. A pilot project where such innovative solution is presented.

scholarly journals Steel Beam-Column Joint with Discontinuous Vertical Reinforcing Bars

2015 ◽  
pp. 197-204
Author(s):  
Ju-Yun Hu ◽  
Won-Kee Hong ◽  
Seon-Chee Park ◽  
Jisoon Kim
Keyword(s):  
Load Transfer ◽  
Precast Concrete ◽  
Steel Plates ◽  
Steel Beam ◽  
Test Results ◽  
Reinforcing Bars ◽  
Concrete Frames ◽  
Steel Members ◽  
Column Joint ◽  
In Parenthesis

The authors proposed steel beam-column connections for precast concrete frames in previous studies. The steel-concrete composite frames provided fast assembly time as steels with economy of concrete structures. However, when enough space is not available at column-beam joints steel sections from beams cannot be connected with column brackets. This paper suggests that some vertical reinforcing bars are disconnected at joints by connecting vertical steel reinforcements to steel plates placed above and below column steels to provide load transferring path. Loads from re-bars are transferred to steel plates, column steels and back to steel plates and re-bars below column steels. Re-bars connected to steel plates by bolts at above and below column steel are discontinued at joint to provide spaces for connections between column brackets and beam steels. Extensive experiments were performed to verify load transfer from re-bars to steel plates above joints and steel plates to re-bars below joint. The flexural load bearing capacity of a column with total of 24 vertical re-bars were compared to columns with discontinuous re-bars at joints. The number of discontinuous re-bars at joint used in column specimen was 0 (0.0%), 4 (16.7%), 12 (50.0%), and 20 (83.3%). The numbers in parenthesis are the percentages of discontinuous rebars to the total number of vertical re-bars of control column. Experiments showed how loads from vertical steel reinforcements that were cut off at joints were transferred to steel plate. The test results also demonstrated that a part of flexural capacities were reduced for specimen with discontinuous vertical re-bars. The reduction of 6.0 %, 13.7% and 54.0% of flexural capacities were observed for columns with 4 (16.7%), 12 (50.0%) and 20 (83.3%) discontinuous vertical rebars, respectively. The test results can be used to design vertical reinforcing bars and column joints that can provide space for column brackets to which steel members of beams are connected.

scholarly journals Behaviour of Horizontal Connections in Precast Walls under Lateral Loading

2019 ◽  
Vol 8 (3) ◽  
pp. 436-440
Keyword(s):  
Load Transfer ◽  
Precast Concrete ◽  
High Strength ◽  
Structural Performance ◽  
Horizontal Connections ◽  
Wall Specimen ◽  
Efficient Load Transfer ◽  
Precast Walls ◽  
Strength And Ductility ◽  
Better Than

The design of connections is one of the most important considerations in the structural design of precast concrete structures. The purpose of the connection is to transfer loads, restrain movement and provide stability. Within one joint there may be several load transfers, each one must be designed for adequate strength and ductility and appropriately detailed. The proposed investigation aims to achieve efficient horizontal connections in precast walls with improved structural performance under various loads. HYSD reinforcement dowels are used as connectors. The arrangement of dowels is varied to achieve the efficient load transfer in the walls. The experimental investigation on three precast wall and one monolithic wall depicts that the precast wall exhibits high strength than the monolithic wall specimen and structural performance were found to be better than the monolithic wall specimen and also the efficient load transfer is achieved in the precast wall

scholarly journals KESIAPAN KECAMATAN DALAM MENERIMA DAN MELAKSANAKAN PELIMPAHAN SEBAGIAN KEWENANGAN PEMERINTAHAN DARI BUPATI KEPADA CAMAT DI KABUPATEN CIANJUR PROVINSI JAWA BARAT

2016 ◽  
Vol 6 (1) ◽  
pp. 55
Author(s):  
Riswati Riswati ◽  
Muslim Muslim
Keyword(s):  
Qualitative Research ◽  
Public Services ◽  
Pilot Project ◽  
Regional Government ◽  
The Public ◽  
Descriptive Research ◽  
Delegation Of Authority ◽  
Important Position ◽  
And Function ◽  
Role And Function

AbstractStructuring the territory understood as a method and not a fi nal destination in the structure ofgovernance (local). The ultimate goal in governance or regional government is the achievementof social welfare. Structuring the region as a method intended to bring the device to the localcommunity as the owner of sovereignty.Sub-District as a working area of the district head has an important position in the publicservice, because it deals directly with the public as the main consumers of public services inquestion. Important essence of districts explicitly stated in Law No. 32 of 2004, which confi rmedthat the sub-district serves as the district/city.This research uses descriptive research design analysis with a qualitative approach. This studyincludes qualitative research, which produces descriptive data. Qualitative research is alsomore emphasis on process rather than in terms of results, in addition to this research mayreveal a problem concerning what is in accordance with the reality on the ground.Based on the results of research and discussion as well as the data obtained in the fi eld,it can be concluded as follows: 1) decree No. 44 and No. 45 of 2012 issued on December28, 2012 have not been fully implemented. The Regent of new regulations implemented infour districts as a pilot project for the District Campaka and Cidaun representing southerncoastal areas Cianjur berkarateristik ocean regions and the mainland. While CematanPacet and Middle Reef representing the Highlands and the Regional Tourism; 3) Basedon the results of questionnaires distributed researchers showed that almost 94% of theauthority delegated by declaring that have been implemented by the Head Campaka,Cidaun, Karangtengah and Pacet despite many obstacles. 4) Based on the interview withthe Head Campaka, Cidaun, Karangtengah and Pacet and the districts mentioned thatthe authority delegated in accordance with Law No. 32 of 2014 governing authority of theRegent. But the delegation of authority was not followed denganpembiayaan suffi cient; 5)Obstacles encountered in the implementation of devolved government affairs, among others,the allocation of funds from the budget has been no improvement since the publication oflegislation or declaring the partial delegation of authority so that what is being implementedby kecamaatan still in accordance with the regulations and declaring before it was issued.Another was in the delegation of authority should be delegated the funds and personnel aswell as the completeness of facilities and infrastructure to carry out the delegated authority;Of the conclusions that can be drawn up by the author, the author tries to give somerecommendations, among others: 1) the ineffectiveness of the role and function of districts foris probably due to the limited authority given to districts to districts that causes districts “nothesitate” to take action if social problems arising in the areas they work; 2) In addition, untilnow there is no synchronization of activity between districts and other institutions at the districtlevel (vertical and horizontal); 3) Short-term: through the synchronization of activities andmake districts as an important actor in the management of these activities, the medium term:to simplifi cation institutions where local authorities through applicable legislation activate therole and functions of the district. Long-term: to reduce the role and function of districts to onlyfocus on one function, namely the function of public services. But we realize that this causes motion districts arena becomes very, very limited, while the other functions being in the arena of motion districts.Keywords: government, delegation of authority and district

scholarly journals Vertical Bearing Capacity of Precast Pier Foundation Filled with Demolished Concrete Lumps

2021 ◽  
Author(s):  
Bin Lei ◽  
Wengui Li ◽  
Zhuo Tang ◽  
Fuzhi Yang
Keyword(s):  
Bearing Capacity ◽  
Shear Failure ◽  
Load Transfer ◽  
Precast Concrete ◽  
Utilization Efficiency ◽  
Soil System ◽  
Ordinary Concrete ◽  
Local Shear ◽  
S Curve ◽  
Vertical Bearing

The application of recycled compound concrete made of demolished concrete lumps (DCLs) and fresh normal concrete in pier foundation can effectively improve the utilization efficiency of construction waste resources. In this study, two prefabricated pier foundations based on recycled compound concrete (dimension of Ø800 × 2500 mm and Ø1000 × 2500 mm) and two cast-in-place pier foundations based on ordinary concrete (dimension of Ø800 × 2500 mm and Ø1000 × 2500 mm) were tested. Special attention was devoted to the load-settlement curve characteristics of the precast pier foundation of compound concrete, the load transfer law of the pier-soil system, the soil pressure distribution at the bottom of the pier, and the failure mode. The results showed that the Q-S curve of precast concrete pier foundation made of recycled compound concrete is slow deformation at loading, which is consistent with that of cast-in-place concrete pier foundation. The load transfer theory of pier-soil system is established, and its accuracy is verified by experimental analysis. The precast foundation of recycled compound concrete is the same as the cast-in-place foundation of ordinary concrete. The failure form of prefabricated pier foundation made of recycled compound concrete was a local shear failure, while the failure form of ordinary concrete cast-in-place pier foundation was piercing-type shear failure. The feasibility of relevant theoretical methods for calculating the vertical ultimate bearing capacity is examined.

scholarly journals Gas brazing of thin-sheet galvanized steel with aluminum solders

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Vitaliy Polishchuk ◽  
Nataliya Strelenko ◽  
Vladyslav Kovalenko
Keyword(s):  
Base Metal ◽  
Thin Sheet ◽  
Zinc Coating ◽  
Base Material ◽  
Galvanized Steel ◽  
Liquid Solder ◽  
Physicochemical Processes ◽  
Brazed Joint ◽  
Coated Layer ◽  
Qualitative Characteristics

. In this work, the first stage of experimental research was carried out to estimate the main physicochemical processes that determine the qualitative characteristics of a brazed joint made of thin sheet galvanized steel during gas brazing with aluminum solder systems. In particular, an estimation was made of the ability of spreading and wetting of aluminum solders (AlSi5, AlSi12) on the surface of thin sheet galvanized steel ( DX56D + Z of 0.4 mm thick and zinc-coated layer of 45–65 microns) at a step-by-step increase in the heating area of the base metal in the presence and absence of flux (Al-Flux 726). The aluminum alloys was heated “not directly,” but through the base metal to maximize the preservation of the anticorrosive zinc coating at the interface between the liquid solder and the base material.

scholarly journals Recent Advances in the Research of the Seismic Response of RC Precast Buildings at the University of Ljubljana

2021 ◽  
Vol 7 ◽  
Author(s):  
Blaž Zoubek ◽  
Anže Babič ◽  
Matjaž Dolšek ◽  
Matej Fischinger ◽  
Tatjana Isaković
Keyword(s):  
Seismic Response ◽  
Fragility Curves ◽  
Precast Concrete ◽  
Structural System ◽  
Design Procedures ◽  
Cyclic Behaviour ◽  
Displacement Capacity ◽  
Precast Buildings ◽  
Cladding Panels ◽  
The University

Although in Europe, precast concrete buildings had been built for decades, their seismic response was poorly understood, which is reflected in ambiguous code requirements and conservative design approaches. Therefore, this structural system was the main focus of several European research projects in the past 2 decades. The University of Ljubljana was actively involved in these projects. The key results of the work performed at the University of Ljubljana are presented and discussed in this paper. The main contributions include: a) the development of a new capacity model of beam-column dowel connections, which are one of the critical parts of the RC precast structural system, b) new insight into the cyclic behaviour of fastening systems of concrete cladding panels, and new design procedures for the estimation of strength and displacement capacity of cladding fasteners, c) the development of a methodology for seismic fragility analysis of RC precast buildings, and the fragility curves of precast RC building classes, which can be used for the safety-calibration of the new design procedures of RC precast buildings, and d) the development of a relatively simple and economically attractive back-up (strengthening) system to prevent the falling of panels in case of a strong earthquake.

scholarly journals Gambaran Pelaksanaan Serah Terima Antar Shift di Rumah Sakit X Jakarta

2020 ◽  
Vol 14 (3) ◽  
pp. 383-390
Author(s):  
Amalia Cahyaningtyas ◽  
Hanny Handayani ◽  
Aat Yatnikasari
Keyword(s):  
Role Play ◽  
Pilot Project ◽  
Head Nurse ◽  
Analysis Study ◽  
Fishbone Diagram ◽  
Nursing Ward ◽  
And Function ◽  
Role And Function

A description of handover processes in hospital: A survey from Jakarta, IndonesiaBackground: Handover at the change of nurse shift is one of an important role in patient safety and continuiting quality of care.Purpose: To optimization of implementation of handover processes in hospital: A survey from Jakarta, IndonesiaMethod: An analysis study with approach fishbone diagram, start with filling in questionnaires, observations and interviews and then analyzed using fishbone diagrams. Based on fishbone diagrams, the problem was obtained that the implementation of handover of patient patients was not optimal.Results: To optimize the implementation of handover, implementation was carried out in the form of improving SPO, improving nurses' effective communication with SBAR and making role play video handover.Conclusion: The result is the handover can be optimal with the role and function of management of the head nurse especially a directing role. Recommendations given by follow up and revising the hand over standars, make a pilot project nursing ward and evaluate the implementation of the patient's handover through regular supervision.Keywords: Fishbone Diagram; Handover; Head Nurse; Optimization; DirectingPendahuluan: Serah terima perawat antar shift jaga merupakan salah satu komponen penting dalam mencapai keselamatan pasien dan mempertahankan kualitas asuhan.Tujuan: Meningkatkan optimalisasi fungsi pengarahan kepala ruang dalam pelaksanaan serah tertima antar shift di RS X Jakarta.Metode: Menggunakan study analysis situasi dengan pendekatan diagram tulang ikan, dimulai dengan mengisi kuesioner, observasi dan wawancara dan kemudian dianalisis menggunakan diagram tulang ikan. Berdasarkan diagram tulang ikan, masalah diperoleh bahwa pelaksanaan serah terima pasien pasien belum optimal.Hasil: Untuk mengoptimalkan pelaksanaan serah terima, implementasi dilakukan dalam bentuk meningkatkan SPO, meningkatkan komunikasi efektif perawat dengan SBAR dan membuat role play video serah terima.Simpulan: Hasilnya adalah serah terima dapat dioptimalkan dengan peran dan fungsi manajemen kepala ruang  khususnya fungsi pengarahan. Rekomendasi yang diberikan dengan menindaklanjuti dan merevisi SOP serah terima, membuat ruang percontohan dan mengevaluasi pelaksanaan serah terima pasien melalui pengawasan rutin.

Sign in / Sign up

Export Citation Format

Share Document