scholarly journals DUCTILITY OF REINFORCED CONCRETE SUB FRAME FOR INDUSTRIALIZED BUILDING SYSTEM

2019 ◽  
Vol 81 (2) ◽  
Author(s):  
Ahmed Sabah Aljawadi ◽  
Abdul Kadir Marsono ◽  
Che Ros Ismail
Keyword(s):  
Reinforced Concrete ◽  
Earthquake Engineering ◽  
Precast Concrete ◽  
Accurate Determination ◽  
Concrete Specimen ◽  
Reinforced Concrete Beams ◽  
Test Scheme ◽  
Conventional Concrete ◽  
Frame System ◽  
Building System

An accurate determination of industrialized building system (IBS) frames ductility under alternating lateral loads is the key issue of this study. The performance features of IBS H frame assembly subjected to cyclic lateral pushover test with six attached IBS components are reported. A test scheme of nonlinear elastic sub-frame system is proposed to build an IBS structural building system. This system complies with the requirements of strength and ductility governed by European Codes 2 and 8. The three models are a conventional reinforced concrete H frame system CRCH (Model 1), IBS with steel conventional links as reinforcements IBSHN (Model 2), and special spiral links concrete IBSHS (Model 3). Each model is scaled to 1:5. All models are laboratory examined under cyclic lateral pushover test to failure, where the IBS connections are considered as hybrid partial rigid linking beams to columns. The beam ends are connected to column boxes via a U shaped steel plate. The experimental results of the IBS specimens are compared with the conventional reinforced concrete connection of similar shapes and size in the form of H sub-frame mechanism tested under the same condition. The models are subjected to cyclic lateral load controlled applied at the beam-column connection. The performance evaluation of IBS connections is made via load displacement hysteresis, ultimate and collapse parameter, ductility index, and surface cracks appearances. The conventional concrete specimen is obviously found to display better strength compared to IBS. Conversely, the ductility of IBS H frame specimen with spiral shear links and conventional closed loop links exhibits superior features compared to the conventional concrete specimen which is beneficial to earthquake engineering. It is demonstrated that the performance of the precast concrete structure is highly dependent on the ductile capacity of connectors to each of the IBS component. This is significant especially at the joints such as the beam-to-column connections. Our systematic methods on ductility characterizations of reinforced concrete beams may contribute toward the development of IBS in resisting earthquakes.

Flexural Performance of Reinforced Concrete Built-up Beams with SIFCON

2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Conventional Concrete ◽  
Flexural Performance ◽  
Load Carrying ◽  
Fiber Concrete

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.

Case Studies of Seismic Vibration Control of Civil Structures Using Shape Memory Alloys

2011 ◽  
Vol 243-249 ◽  
pp. 5427-5434
Author(s):  
Hui Qian ◽  
Hong Nan Li ◽  
Di Cui ◽  
Huai Chen
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Vibration Control ◽  
Case Studies ◽  
Precast Concrete ◽  
Reinforced Concrete Beams ◽  
Seismic Vibration ◽  
Concrete Members

Shape memory alloys (SMAs) are unique class materials that have the ability to undergo large deformations, while returning to their undeformed shape through either the applications of heat (SME) or removal of stress (SE). The unique properties lead to their wide applications in the biomedical, mechanical, aerospace, commercial industries, and recently in civil engineering. The paper presents two case studies of structural seismic vibration control using SMAs. The first one is a study of the SMA reinforced RC members. Two innovative applications in RC members, such as SMA-based Precast Concrete Frame Connection (SMA-PCFC), and SMA reinforced RC short column, were proposed. Moreover, the self-rehabilitation properties of SMAs-based Intelligent Reinforced Concrete Beams (SMA-IRCBs) were further experimentally investigated. The results show that SMAs can improve the mechanical properties of concrete members. SMA reinforced RC members have unique seismic performance compared to ordinarily steel reinforced concrete members. The second one is a study of the structural energy dissipation system using SMAs damping device. An innovative hybrid SMAs friction device (HSMAFD) which consists of pre-tensioned superelastic SMA wires and friction devices (FD) was presented. The results of cyclic tensile tests show that the HSMAFD exhibits stable large energy dissipation capacity and re-centering feature. The effectiveness of the HSMAFD in reducing horizontal response of structures subjected to strong seismic excitations was verified through shaking table tests carried out on a reduced-scale symmetric steel frame model with and without the HSMAFD.

The effect of assembling location on the performance of precast concrete beam under impact load

2017 ◽  
Vol 21 (8) ◽  
pp. 1211-1222 ◽  
Author(s):  
Qiushi Yan ◽  
Bowen Sun ◽  
Xuemei Liu ◽  
Jun Wu
Keyword(s):  
Reinforced Concrete ◽  
Impact Velocity ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Impact Load ◽  
Precast Concrete ◽  
Reinforced Concrete Beams ◽  
Impact Location ◽  
Weight Impact ◽  
The Impact

With incorporation of assembling joints, precast concrete beams could behave very differently in resisting both static and dynamic loads in comparison to conventional reinforced concrete beams. With no research available on the dynamic behavior of precast concrete beams under impact load, a combined experimental and numerical study is conducted to investigate the dynamic response of precast concrete beams under impact load. The results were also compared with reinforced concrete beams. Four groups of concrete beams were tested with all beams designed with the same reinforcement, but different assembling locations were considered for precast concrete beams. The effects of the assembling location in resisting drop weight impact of precast concrete beams were analyzed. The influence of impact mass and impact velocity on the impact resistance of precast concrete beams were also investigated. The results revealed that the further the assembling location is away from the impact location, the closer the mechanical performance of the precast concrete beam is to that of the reinforced concrete beam. When the assembling location and the impact location coincided, the assembling region suffered from severe local damages. With increased impact velocity and impact energy, the damage mode of the precast concrete beams may change gradually from bending failure to bending–shear failure and eventually to local failure. In addition, the bonding around the assembling interface was found to be effective to resist drop weight impact load regardless of the magnitude of the impact velocity and energy.

Seismic Testing and Verification of a 1/25 Scaled-Down Reinforced Concrete Specimen for the Reactor Building

2015 ◽  
Vol 764-765 ◽  
pp. 1129-1133
Author(s):  
Wei Ting Lin ◽  
Yuan Chieh Wu ◽  
An Cheng ◽  
Hui Mi Hsu
Keyword(s):  
Reinforced Concrete ◽  
Earthquake Engineering ◽  
Nuclear Power ◽  
Structural Integrity ◽  
Concrete Specimen ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Self Consolidating Concrete ◽  
Reactor Building ◽  
Scale Down

A 1/25 scale-down specimen was constructed of a reinforced concrete reactor building used in the nuclear power plant. The non-demoulding technology and self-consolidating concrete were used to cast the specimen with a length of 2.9 m, width of 2.9 m, height of 2.9 m and weight of 28 tons. The entirety struc-ture was composed of a primary containment (thickness of 10 cm), a secondary containment (thickness of 7.5 cm) and three floors (thickness of 30 and 15 cm). Shaking table tests were conducted on it in the National Center for Research on Earthquake Engineering. Testing results indicated that the scale-down specimen kept the structural integrity under a 0.6 g specific seismic wave hit. In addition, the ETABS model accurately represented the dynamic characteristics of the scale-down specimen by numerical method obtained the conservative results.

scholarly journals STRENGTH OF HIGHER STRENGTH CONCRETE ELEMENTS UNDER SHEAR ACTION

2018 ◽  
Vol 1 (50) ◽  
pp. 131-140
Author(s):  
O. O. Maliovana
Keyword(s):  
Reinforced Concrete ◽  
Design Method ◽  
Reinforced Concrete Beams ◽  
Variation Method ◽  
Experimental Program ◽  
Inclined Crack ◽  
Conventional Concrete ◽  
Strength Concrete ◽  
Strength Design ◽  
Concrete Elements

The strength design method of concrete and reinforced concrete elements is expounded in this article. The experimental program included the study of the strain condition and failure load determination for considered types of elements. The strength design method is expounded for concrete and reinforced concrete elements by means of variation method in the concrete plasticity theory that was developed in Poltava National Technical Yuri Kondratyuk University. There are the results of experimental investigation for truncated concrete wedges that simulate work of concrete compressed zone above dangerous inclined crack, Hvozdev specimens and crucial keys as well as beams. Also all elements were made of higher strength concrete in order to test the applicability of given method to these elements. The results of the experimental research have confirmed the applicability of plasticity zones assumed in the theoretical solutions. The theoretical strength is well coordinated with the experimental one. The failure character of reinforced concrete beams has been discovered. It has not differed from the flexure elements failure by cross section made of conventional concrete.

scholarly journals Performance Monitoring of Re-Engineered CRCP Test Sections: Volume 2

2021 ◽  
Author(s):  
Sachindra Dahal ◽  
◽  
Jeffery Roesler ◽  
Prakhar Gupta ◽  
Yating Zhang ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Performance Monitoring ◽  
Reinforced Concrete Beams ◽  
Conventional Concrete ◽  
Crack Control ◽  
Innovative Methods ◽  
And Performance ◽  
Control Terminal ◽  
Initial Results ◽  
Design Construction

Innovative methods in structural design, concrete materials, construction processes, and support layer selection and design were proposed to improve the performance of continuously reinforced concrete pavement (CRCP). With the aim of making CRCP more economical initially, the proposed ideas were evaluated by constructing two 500 ft. long continuously reinforced concrete beams (CRCB) in Rantoul, IL. The CRCB were also instrumented to monitor responses under environmental loading for various design and material changes such as steel content, internally-cured concrete, active crack control, and macro-fibers. Adopting the initial results of the CRCB sections, three experimental CRCP test sections were also constructed by the Illinois Tollway in 2016 and 2017. These sections evaluated the effects of steel content (0.58% versus 0.80%), base type and interface, internal cure versus conventional concrete, active crack control, terminal joint design, and macro-fiber addition on the crack properties and pavement responses. Details about the design, construction, and performance of the CRCB and CRCP sections are presented in this volume.

Embedded smart sensor dipole antennas for real-time damage assessment, humidity, and temperature monitoring in reinforced and non-reinforced concrete structures

2021 ◽  
pp. 1-10
Author(s):  
Murat Ozturk
Keyword(s):  
Reinforced Concrete ◽  
Resonance Frequency ◽  
Real Time ◽  
Damage Assessment ◽  
Concrete Structures ◽  
Concrete Specimen ◽  
Dipole Antenna ◽  
Temperature Monitoring ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures

Abstract In this study, a dipole antenna is designed for real-time damage assessment, humidity, and temperature monitoring in reinforced and non-reinforced concrete structures. The antenna-based sensor is embedded into reinforced and non-reinforced concrete beams to assess electromagnetic measurements. Reflection parameter S11 in dB values and resonant frequencies of the embedded antenna are evaluated to detect damage, humidity, and temperature changes. The exploratory results show that as deformation increases in reinforced concrete, resonance frequency values decrease and S11 values increase. The load and resonance frequency values showed very close trends as deformation increases in the beam. In water content sensing experiments, the S11 in dB values of the antenna decrease as the humidity increases for concrete specimens while the resonance frequency values increase as the humidity increases for the reinforced concrete specimen. Elevated temperature sensing experimental results show that the resonance frequency values of the antenna decrease as the temperature of the specimen increases for concrete specimens while the S11 in dB values increase as the temperature of the specimen increases for reinforced concrete specimen.

Basic parameters of crack resistance of conventional and damaged reinforced concrete beams strengthened by carbon plastic under the action of a high-level load.

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
V. Karpiuk ◽  
R. Hlibotskyi
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Concrete Beams ◽  
Precast Concrete ◽  
Limit State ◽  
Experimental Studies ◽  
Reinforced Concrete Beams ◽  
Physical Models ◽  
Carbon Plastic ◽  
Beam Position

The main results of experimental studies of the fracture resistance of conventional and damaged and brought to the limit state according to I group in the previous experiments of reinforced concrete beams reinforced with fiberglass carbon fiber (СFRP) in the lower stretched zone and at the supporting areas. According to the adopted methodology, a full-scale experiment was performed on a four-factor three-level Box-Bank B4 plan. The tests of the prototypes were carried out according to the scheme of a single-track free-beam, alternately loaded from above, then from below by two concentrated forces without changing its (beam) position. During testing of the test specimens-beams for the action of short- term one-time and small-cycle loads, the formation, development and width of crack opening on their surface were monitored. The width of the opening  of normal cracks was determined at the level of the stretched working armature, and the inclined ones - in the middle of the height of the beam in places where it was visually greatest. Due to the adopted methodology, new experimental data were obtained to substantially refine the physical models of the inclined sections of the precast concrete structures by the action of low-cycle reloading of high levels, resulting in the first identified systemic effect on fracture toughness. Keywords: concrete, reinforcement, carbon fiber fabric (CFRP), reinforced concrete beam, normal and inclined cracks, deformations.

scholarly journals Flexural Behaviour of Hybrid Fibre Reinforced Concrete Beam by using (LC3) Cement

2019 ◽  
Vol 9 (1S3) ◽  
pp. 460-465
Keyword(s):  
Reinforced Concrete ◽  
Young’S Modulus ◽  
Concrete Beams ◽  
Young's Modulus ◽  
Absorption Capacity ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Fibre Reinforced Concrete ◽  
Conventional Concrete ◽  
Hybrid Fibre

In this paper, the flexural behavior of hybrid fibre reinforced concrete beams was investigated. Two types of hybrid fibres were used. used in this study, one is having high young’s modulus steel fibre (Hooked end) and another one is having low young’s modulus Polypropylene fibre with different proportions. Nine types of reinforced concrete beams were made by using M50 grade high strength concrete mix a volume factors of hybrid fibres as 1.5%. this beams includes conventional concrete, LC3 concrete and he beam with the following combinations of hybrid fibres such as OPC 100%, LC3 100%, SF100%, SF25% -PF75%, SF40%-PF60%, SF50%-PF50%, SF60%-PF40%, SF75%-PF25 %, PF100%, the working results shows that percentage proportion of combined SF-PF at 75%-25% had the best implementation on its flexural strength. Experimental results also shows that beam with SF75%-PF25% had their structural stiffness, ductility index and energy absorption capacity have been improved the most as compared with the conventional concrete and other fibre combinations of beams.

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