scholarly journals Development of Narrow Loop Joint for Precast Concrete Slabs with Fiber-Reinforced Mortar: Experimental Investigation of Material Properties and Flexural Behavior of Joint

2021 ◽  
Vol 11 (17) ◽  
pp. 8235
Author(s):  
Shuichi Fujikura ◽  
Minh Hai Nguyen ◽  
Shotaro Baba ◽  
Hiromi Fujiwara ◽  
Hisao Tategami ◽  
...  
Keyword(s):  
Concrete Slab ◽  
Precast Concrete ◽  
Highway Bridges ◽  
Flexural Behavior ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slab ◽  
Suitable Material ◽  
Girder Bridges ◽  
Steel Girder Bridges

In the replacement of the reinforced concrete slab in existing steel girder bridges, a loop joint is commonly used to join precast concrete slabs on site. However, a relatively wide joint is needed, and considerable time and effort are consumed to construct the joint due to the addition of transverse reinforcements to the joint on site. These disadvantages affect the progress of on-site construction and should be addressed, especially when this method is applied to highway bridges, where early traffic opening is necessary in many cases. This study proposes a narrow loop joint that has fiber-reinforced mortar without transverse reinforcements. Several material tests were conducted to determine a suitable material for the joint. A series of flexural loading tests of slabs was conducted to investigate the flexural behavior of the proposed loop joint with the selected material (polyvinyl alcohol (PVA) fibers). The results showed that the flexural capacity and deformation performance of the proposed joint with PVA fibers are equivalent to those of the conventional loop joint.

scholarly journals Numerical Modeling and Analysis of Concrete Slabs in Interaction with Subsoil

2020 ◽  
Vol 12 (23) ◽  
pp. 9868
Author(s):  
Radim Cajka ◽  
Zuzana Marcalikova ◽  
Vlastimil Bilek ◽  
Oldrich Sucharda
Keyword(s):  
Numerical Modeling ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Fiber Reinforced Concrete ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slab ◽  
Modeling And Analysis ◽  
Non Linear

This article focuses on the analysis and numerical modeling of a concrete slab interacting with subsoil. This is a complex task for which a number of factors enter into the calculation, including the scope or dimension of the model, the non-linear solution approach, the choice of input parameters, and so forth. The aim of this article is to present one possible approach, which is based on a non-linear analysis and a three-dimensional computational model. Five slabs were chosen for modeling and analysis. The experiments involved slabs of 2000 × 2000 mm and a thickness of 150 mm, which were tested using specialized equipment. The slabs included a reinforced concrete slab, a standard concrete slab, and three fiber-reinforced concrete slabs. The fiber-reinforced slabs had fiber volume fractions of 0.32%, 0.64%, and 0.96%, which corresponded to fiber dosages of 25, 50, and 75 kg/m3. A reinforced concrete slab was chosen for the calibration model and the initial parametric study. The numerical modeling itself was based on a detailed evaluation of experiments, tests, and recommendations. The finite element method was used to solve the three-dimensional numerical model, where the fracture-plastic material of the model was used for concrete and fiber-reinforced concrete. In this paper, the performed numerical analyses are compared and evaluated, and recommendations are made for solving this problem.

Dimension and Frequency Profiles of Concrete Highway Bridges in New Madrid Region of Southeastern Missouri

1997 ◽  
Vol 1594 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Ralph Alan Dusseau
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Highway Bridges ◽  
Ambient Vibration ◽  
Earthquake Hazards ◽  
Empirical Formulas ◽  
Reinforced Concrete Slab ◽  
Box Girder ◽  
Bridge Spans ◽  
New Madrid

The results of a study funded by the U.S. Geological Survey as part of the National Earthquake Hazards Reduction Program are presented. The first objective of this study was the development of a database for all 211 highway bridges along I-55 in the New Madrid region of southeastern Missouri. Profiles for five key dimension parameters (which are stored in the database) were developed, and the results for concrete highway bridges are presented. The second objective was to perform field ambient vibration analyses on 25 typical highway bridge spans along the I-55 corridor to determine the fundamental vertical and lateral frequencies of the bridge spans measured. These 25 spans included six reinforced concrete slab spans and two reinforced concrete box-girder spans. The third objective was to use these bridge frequency results in conjunction with the dimension parameters stored in the database to develop empirical formulas for estimating bridge fundamental natural frequencies. These formulas were applied to all 211 Interstate highway bridges in southeastern Missouri. Profiles for both fundamental vertical and lateral frequencies were then developed, and the results for concrete highway bridges are presented.

scholarly journals Ductility and flexure of lightweight expanded clay basalt fiber reinforced concrete slab

2021 ◽  
Vol 17 (1) ◽  
pp. 74-81
Author(s):  
Vera V. Galishnikova ◽  
Alireza Heidari ◽  
Paschal C. Chiadighikaobi ◽  
Adegoke Adedapo Muritala ◽  
Dafe Aniekan Emiri
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Lightweight Aggregate Concrete ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Chopped Basalt Fiber

Relevance. The load on a reinforced concrete slab with high strength lightweight aggregate concrete leads to increased brittleness and contributes to large deflection or flexure of slabs. The addition of fibers to the concrete mix can improve its mechanical properties including flexure, deformation, toughness, ductility, and cracks. The aims of this work are to investigate the flexure and ductility of lightweight expanded clay concrete slabs reinforced with basalt fiber polymers, and to check the effects of basalt fiber mesh on the ductility and flexure. Methods. The ductility and flexural/deflection tests were done on nine engineered cementitious composite (expanded clay concrete) slabs with dimensions length 1500 mm, width 500 mm, thickness 65 mm. These nine slabs are divided in three reinforcement methods types: three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm (first slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed chopped basalt fiber plus basalt fiber polymer (mesh) of cells 2525 mm (second slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed basalt fiber of length 20 mm, diameter 15 m (third slab type). The results obtained showed physical deflection of the three types of slab with cracks. The maximum flexural load for first slab type is 16.2 KN with 8,075 mm deflection, second slab type is 24.7 KN with 17,26 mm deflection and third slab type 3 is 32 KN with 15,29 mm deflection. The ductility of the concrete slab improved with the addition of dispersed chopped basalt fiber and basalt mesh.

scholarly journals IDENTIFIKASI FAKTOR PENGARUH DOMINAN KETERLAMBATAN PROYEK AKIBAT RANTAI PASOK PADA PENGADAAN PELAT BETON PRACETAK

2020 ◽  
Vol 3 (4) ◽  
pp. 1295
Author(s):  
Firena Bian Saputri ◽  
Basuki Anondho
Keyword(s):  
Supply Chain ◽  
Human Error ◽  
Concrete Slab ◽  
Precast Concrete ◽  
Influence Factors ◽  
Concrete Slabs ◽  
Literature Study ◽  
Factors Affecting ◽  
Project Duration ◽  
Speed Up

One way that can be done to speed up the duration of the project is to use precast concrete slabs. However, the use of precast concrete slab elements in the project can be ineffective if in the order stage, production stage, until the delivery stage of precast concrete elements to the project site is not managed properly, which can cause delays in project duration. Therefore, the use of precast concrete slabs is very dependent on the supply chain management. To anticipate this risk, it is necessary to identify what are the dominant factors in the supply chain that affect the procurement of precast concrete slabs which can cause delays in project duration. The initial influence factors were collected through a literature study and interviews with a number of practitioners, followed by a survey using a questionnaire to a number of project actors in projects using precast concrete slabs. The Likert scale 1-5 is used to measure the level of influence of a factor identified on project delays. By using factor analysis techniques, as many as three groups of dominant supply chain factors affecting the procurement of precast concrete slabs were found, namely special factors, technical factors, and human error factors.ABSTRAKSalah satu cara yang dapat dilakukan demi mempercepat durasi proyek adalah menggunakan pelat beton pracetak. Namun, penggunaan elemen pelat beton pracetak di proyek bisa tidak efektif apabila dalam tahap pemesanan, tahap produksi, hingga tahap pengiriman elemen beton pracetak ke lokasi proyek tidak dikelola dengan baik, sehingga dapat menyebabkan keterlambatan durasi proyek. Oleh sebab itu, penggunaan pelat beton pracetak sangat bergantung pada manajemen rantai pasokannya. Untuk mengantisipasi risiko tersebut, perlu adanya identifikasi mengenai faktor dominan apa saja pada rantai pasok yang mempengaruhi pengadaan pelat beton pracetak yang dapat menyebabkan keterlambatan durasi proyek. Faktor pengaruh awal dikumpulkan melalui studi literatur dan wawancara kepada sejumlah praktisi, dilanjutkan dengan survei menggunakan kuesioner kepada sejumlah pelaku proyek di proyek yang menggunakan pelat beton pracetak. Skala Likert 1-5 digunakan untuk mengukur tingkat pengaruh suatu faktor yang diidentifikasi terhadap keterlambatan proyek. Dengan menggunakan teknik analisis faktor, sebanyak tiga kelompok faktor dominan rantai pasok yang berpengaruh pada proses pengadaan pelat beton pracetak ditemukan, yaitu faktor khusus, faktor teknis, dan faktor human error.

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