scholarly journals Long-Term Behavior of RC Beams Strengthened with Hybrid Composite Beam

2019 ◽  
Vol 9 (9) ◽  
pp. 1734
Author(s):  
IL-Heon Kim ◽  
Hyung-Joo Lee ◽  
Joo-Won Kang ◽  
Yeol Choi
Keyword(s):  
Hybrid Composite ◽  
Composite Beam ◽  
American Concrete Institute ◽  
Time Dependent ◽  
Rc Beams ◽  
Experimental Conditions ◽  
Sustained Loads ◽  
Long Term Behavior ◽  
Hybrid Composite Beam

This paper describes the results of long-term tests on reinforced concrete (RC) beams strengthened with hybrid composite beam (HCB) under two different sustained loads. Test specimens were fabricated to reflect the most common RC beam size used in school buildings in South Korea. The specimens had dimensions of 400 mm (width) × 600 mm (depth) × 6000 mm (length), and were tested with or without external strengthening by a hybrid composite beam (HCB). Test results showed that strengthening the RC beams with HCB not only reduced the instantaneous deflection but was also effective in decreasing long-term deflection. In this study, time-dependent factors were investigated using a modified version of the American Concrete Institute (ACI) equation. Time-dependent factors of HCB-strengthened RC beams found in the present work differed from those of other investigations due to various experimental conditions. In the present study, we found that the ACI equation may not provide a reasonable estimation of the long-term behavior of HCB-strengthened RC beams.

Lateral Impact of Railroad Bridges With Hybrid Composite Beams: Finite Element Modeling and Preliminary Dynamic Behavior Study of HCB

2014 ◽  
Author(s):  
Yuan Jing ◽  
Z. John Ma ◽  
Richard M. Bennett ◽  
David B. Clarke
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Hybrid Composite ◽  
Composite Beam ◽  
Glass Fibers ◽  
Fe Analysis ◽  
Future Research ◽  
Lateral Impact ◽  
Time Duration ◽  
Hybrid Composite Beam

Grade separations have been used along High-Speed Rail (HSR) to decrease traffic congestion and the danger that occurs at grade crossings. However, the concern with grade separations is the potential damage due to lateral impact of bridge superstructures by over-height vehicles. This is a concern with existing bridges, and lateral impact is not included in standard bridge code provisions. A new bridge technology, Hybrid Composite Beam (HCB), was proposed to meet the requirements of another HSR objective, that of a sustainable solution for the construction of new and replacement bridges in rail infrastructure. The hybrid composite beam combines advanced composite materials with conventional concrete and steel to create a bridge that is stronger and more resistance to corrosion than conventional materials. The HCB is composed of three main parts; the first is a FRP (fiber reinforced polymer) shell, which encapsulates the other two parts. The second part is the compression reinforcement which consists of concrete or cement grout that is pumped into a continuous conduit fabricated into the FRP shell. The third part of the HCB is the tension reinforcement that could consist of carbon or glass fibers, prestressed strands, or other materials that are strong in tension, which is used to equilibrate the internal forces in the compression reinforcement. The combination of conventional materials with FRP exploits the inherent benefits of each material and optimizes the overall performance of the structure. The behavior of this novel system has been studied during the last few years and some vertical static tests have been performed, but no dynamic or lateral impact tests have been conducted yet. Therefore, the main objective of this study is to evaluate the performance of HCB when subjected to lateral impact loading caused by over-height vehicles. This paper explains the advantages of HCB when used in bridge infrastructures. The commercial software ABAQUS was used to perform the finite element (FE) modeling of a 30ft long HCB. Test data was used to validate the results generated by FE analysis. A constant impact loading with a time duration of 0.1 second was applied to an area at the mid-span of the HCB. Lateral deflection and stress distribution were obtained from FE analysis, and local stress concentration can be observed from the stress contour. Full-scale beam dynamic testing will be conducted in the future research to better study the behavior of HCB when subjected to over-height vehicles.

Study on the Flexible Strength of U-shape Hybrid Composite Beam

2012 ◽  
Vol 24 (5) ◽  
pp. 521-534 ◽  
Author(s):  
Sung-Bae Kim ◽  
Sang-Seup Kim ◽  
Won-Rok Lee ◽  
Jung-Yeon Kim ◽  
Seung-Bae Lee ◽  
...  
Keyword(s):  
Hybrid Composite ◽  
Composite Beam ◽  
Hybrid Composite Beam

scholarly journals Enhancing the properties of damar (Agathis loranthifolia Salisb.) wood by making hybrid bamboo-wood composite

2021 ◽  
Vol 914 (1) ◽  
pp. 012066
Author(s):  
D R Trisatya ◽  
M Iqbal ◽  
I M Sulastiningsih
Keyword(s):  
Interior Design ◽  
Hybrid Composite ◽  
Composite Beam ◽  
Promising Result ◽  
Core Layer ◽  
Wood Composite ◽  
Laminated Bamboo ◽  
The Face ◽  
Superior Mechanical Properties ◽  
Hybrid Composite Beam

Abstract This study was carried out to investigate the characteristics of laminated bamboo and damar (Agathis loranthifolia Salisb.) wood as the core layer of the bamboo-damar hybrid composite beam. Andong bamboo (Gigantochloa pseudoarundinacea (Steud.) Widjaja) and mayan bamboo (Gigantochloa robusta Kurz.) were used as the face and back layers of the beam, glued with isocyanate adhesive. Four types of composite beam were produced with various number of laminated bamboo layers. Results showed that the four layers (two layers for each face and back sides) laminated andong bamboo performed superior mechanical properties than others hybrid composite beam, while the four layers (two layers for each face and back sides) laminated mayan bamboo demonstrated the highest compression and bonding strength. The density, MOR, MOE and compression strength of the hybrid composite beam improved 31.3%, 25.95%, 37.81% and 25.12%, respectively, as the outcomes of the incorporation of laminated andong bamboo on the outer layers of the damar board. This paper proves that the number of laminated bamboo layers enhances the properties of the bamboo-damar hybrid composite beam. Furthermore, it shows promising result for complementing furniture and interior design materials as the bamboo-damar hybrid composite beam has remarkable properties.

scholarly journals Effects of Variable Humidity on the Creep Behavior of Concrete and the Long-Term Deflection of RC Beams

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Pengfei Li ◽  
Shiqin He
Keyword(s):  
Experimental Data ◽  
Relative Humidity ◽  
Creep Strain ◽  
Analytical Models ◽  
Deformation Characteristics ◽  
Rc Beams ◽  
Test Results ◽  
Sustained Loads ◽  
Average Relative Humidity

The influences of variable humidity on the creep behaviors of concrete and the long-term deflections of RC beams are analyzed in this paper. A total of 6 prismatic specimens and 5 RC beams were subjected to sustained loads and 3 types of variable humidity conditions for 331 days. The creep strains of the prismatic specimens and the deflections of the RC beams were recorded to investigate the long-term deformation characteristics. The test results reveal that both the creep strain and the deflection of specimens under cyclic humidity conditions exhibit approximately linear tendencies that are obviously less than those of specimens exposed only to natural air. During certain wetting cycles, the deformation rate became slower and the creep strain even recovered with an increase in the humidity, especially for shorter wetting-drying cycles. Long-term deflections predicted using the CEB-FIP 90 and ACI 209R models were compared with the test results to evaluate the versatility of these current specifications. The findings included rather large errors between the predicted results and experimental data when the average relative humidity was adopted in the analytical models.

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