Performance of Skew Reinforcing in Inverted-T Bridge Caps

2018 ◽  
Vol 2672 (41) ◽  
pp. 65-74 ◽  
Author(s):  
Satya Sapath Roy ◽  
Jamshaid Sawab ◽  
Tianmin Zhou ◽  
Y. L. Mo ◽  
Thomas T. C. Hsu
Keyword(s):  
Traditional Method ◽  
Structural Performance ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Physical Test ◽  
Construction Period ◽  
Traditional Arrangement

Inverted-T bridge caps (ITBCs) have been widely used in most bridges in Texas in recent years. In some typical cases, the bridge caps are skew when two roads are not aligned in a perpendicular manner. The traditional method of flaring the transverse reinforcement out in skew ITBCs introduces significant complexity in design and during construction. An alternative is to provide skew reinforcing which will substantially reduce the design complexities and construction period. In this paper, three ITBC specimens were subjected to shear action to evaluate and compare the performance of ITBCs with traditional reinforcing with those with skew reinforcing. The three specimens include 0-degree skew, 30-degree skew with traditional reinforcing, and 30-degree skew with skew reinforcing, worthy of verification and quantification as demonstrated in this paper. The physical test results show that the skew reinforcement arrangement does not weaken the bridge cap’s capacity, and the structural performance remains almost the same as that of the traditional arrangement. In addition, the serviceability performance of skew reinforcements is better as compared with traditional reinforcements.

Bending and Shear Strength of I-Slab with Polystyrene Forms

2008 ◽  
Vol 385-387 ◽  
pp. 353-356 ◽  
Author(s):  
Seung Hun Kim ◽  
K.K. Lee ◽  
Han Seung Lee ◽  
K.J. Lee ◽  
In Seok Kang
Keyword(s):  
Precast Concrete ◽  
The Self ◽  
Punching Shear ◽  
Structural Performance ◽  
Displacement Curve ◽  
Test Results ◽  
Construction Period ◽  
Experimental Works ◽  
Concrete Deck

Where the self weight of the overall slab needs to be considered, the quantity of in-situ concrete required can be reduced by the introduction of polystyrene void forms supplied and fixed to the precast panel during manufacture. In this study, new I-slab system with polystyrene form and precast concrete deck is proposed to reduce the construction period and the self weight of the slab. This paper presents experimental works on the bending and shear of the I-slabs. Five specimens were tested. The main parameters of experiments were the hole diameter of polystyrene form and the thickness of slab. Structural performance of I-slab was evaluated on the basis of failure mode, load-displacement curve, and ultimate strengths. Based on the test results, the critical punching shear sections were changed as test variables, so the punching shear strengths were very different. Test results indicated that the developed I-slab were very effective to increase the strength because of self weight reduction.

Structural Performance of Exterior Beam-Column Joints with Large Diameter Headed Bars

2017 ◽  
Vol 754 ◽  
pp. 337-340
Author(s):  
Hyung Suk Jung ◽  
Hyun Ki Choi ◽  
Chang Sik Choi ◽  
Joo Hong Chung
Keyword(s):  
Reinforced Concrete ◽  
Large Diameter ◽  
Structural Performance ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Reinforced Concrete Structure ◽  
Current Design ◽  
Cover Thickness ◽  
Concrete Placement ◽  
Better Than

Generally, a conventional standard hook is used for the reinforcement's anchorage. However, this results in steel congestion, and it makes fabrication and construction difficult. Using a headed bar offers a potential solution for these problems and may also ease fabrication, construction and concrete placement. But, in current design code of the headed bar, it had limitation about the yield strength and the diameter of rebar etc. It hard to use the large diameter headed bar in the reinforced concrete structure. This paper presents the cyclic responses of four reinforced concrete exterior beam-column joints, which are anchored with large diameter headed bars or hooked bars. To evaluate the anchorage capacity of large diameter headed bars, specimen variables were set with anchorage detail, side cover thickness of concrete, and transverse reinforcement. Also, structural performance of beam-column joints is evaluated and compared with each other. The behavior of joints with headed bars are as good as, or better than those companion joints with 90-degree hooked bars. Test results show that the large diameter headed bar has enough anchorage capacity in exterior beam-column joints. Test results show side cover of concrete improved the anchorage capacity of the bars and transverse reinforcement enhanced the anchorage capacity and ductility of joints.

Experimental study of moment carrying behavior of typical Tibetan timber beam-column joints

2021 ◽  
pp. 136943322110015
Author(s):  
Ting Guo ◽  
Na Yang ◽  
Huichun Yan ◽  
Fan Bai
Keyword(s):  
Bending Moment ◽  
Structural Performance ◽  
Test Results ◽  
Timber Beam ◽  
Rotational Stiffness ◽  
Trilinear Model ◽  
Column Joint ◽  
Loading Tests ◽  
The Moment ◽  
Relationship Of

This study aimed to investigate the moment carrying behavior of typical Tibetan timber beam-column joints under monotonic vertical static load and also evaluate the influence of length ratio of Gongmu to beam (LRGB) and dowels layout on the structural performance of the joint. Six full-scale specimens were fabricated with same construction but different Gongmu length and dowels position. The moment carrying performance of beam-column joints in terms of failure mode, moment resistance, and rotational stiffness of joints were obtained via monotonic loading tests. Test results indicated that all joints are characterized by compressive failure perpendicular to grain of Ludou. Additionally, it was found that greater LRGB leads to greater initial rotational stiffness and maximum moment of the joint by an increase of restraint length for beam end; however, offsetting dowels toward column resulted smaller stiffness and ultimate bending moment of joints, particularly, offsetting Beam-Gongmu dowels toward column changed the moment-rotation curve pattern of the beam-column joint, accompanied by a hardening stiffness at last phase. Furthermore, a simplified trilinear model was proposed to represent the moment-rotation relationship of the typical Tibetan timber beam-column joint.

Debonding Behaviors of CFRP Strengthened RC Beams with Weak Interfaces

2013 ◽  
Vol 351-352 ◽  
pp. 587-591
Author(s):  
Sen Li ◽  
Xiao Gang Wang ◽  
Xin Gang Zhou
Keyword(s):  
Tensile Strain ◽  
Structural Integrity ◽  
Structural Performance ◽  
Rc Beams ◽  
Test Results ◽  
Weak Interface ◽  
Premature Rupture ◽  
Loading Process ◽  
Interface Effects

Debonding behaviors of CFRP strengthened RC beams were experimentally investigated under the influence of weak interfaces, which are induced either by defective bonding of replaced cover or expansive cracks. Shown by test results, weak interfaces impaired considerably the structural integrity of strengthening systems during loading, and easily led to CFRP debonding failure. U-strips worked effectively in preventing the integral debonding and guarantee the structural performance of flexural sheets. However, local cover delamination in the loading process and premature rupture of flexural CFRP could still take place due to the weak interface effects. Therefore, allowable tensile strain of flexural CFRP should be reduced, and more strict confinement and anchorage measures should be taken in this case.

New Method for Measuring Liquid Level in WFGD System

2011 ◽  
Vol 418-420 ◽  
pp. 1804-1807
Author(s):  
Li Li ◽  
Zheng Hui Tan ◽  
Jia Wen Liu
Keyword(s):  
Flue Gas ◽  
Traditional Method ◽  
Large Deviation ◽  
Flue Gas Desulfurization ◽  
New Method ◽  
Liquid Level ◽  
Test Results ◽  
Economic Operation ◽  
Local Test ◽  
Operation Cost

Traditional method for measuring liquid level of absorption tower in wet flue gas desulfurization (WFGD) system is introduced in this paper, and it's found that measuring accuracy of the method exists in large deviation. A new method is proposed to measure liquid level of absorption tower for this situation. The local test results show that not only measurement result of new method is more close to the actual liquid level than traditional method, but also using new method can save operation cost and ensure the safety, stability, and economic operation of WFGD system.

scholarly journals Experimental Study on the Temperature Distribution and Residual Strength of Fire-damaged RC Columns Depending on Heated Areas

2020 ◽  
Vol 20 (3) ◽  
pp. 75-80
Author(s):  
Eunmi Ryu ◽  
Heesun Kim ◽  
Yeongsoo Shin
Keyword(s):  
Temperature Distribution ◽  
Residual Strength ◽  
Axial Loading ◽  
Concrete Columns ◽  
Structural Performance ◽  
Test Results ◽  
Floor Plan ◽  
Heated Area ◽  
Actual Fire ◽  
Asymmetric Heating

Most of the columns in actual fire conditions are heated on partial faces rather than all four sides due to the floor plan, which results in asymmetric behaviors of columns. The asymmetric behaviors of fire-damaged columns may cause more vulnerability to the structural performance. In this study, temperature distribution and residual strength of reinforced concrete columns exposed to fire were investigated according to various heated areas. To achieve the objective, columns were heated for 2 h according to ISO-834 standard time-temperature curve and subsequently tested under the axial loading after a week. The test results show that the residual strength of the fire-damaged columns decreased as the heated area increased, and the residual strength reduced additionally due to asymmetric heating.

scholarly journals Experimental Study on Mechanical Performance of U-Shaped Steel-Encased Concrete Composite Beam-Girder Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhangqi Hu ◽  
Ran He ◽  
Yukui Wang ◽  
Weirong Lv ◽  
Jingchao Li
Keyword(s):  
Composite Beam ◽  
Mechanical Performance ◽  
Concrete Slab ◽  
Bottom Flange ◽  
The Novel ◽  
Test Results ◽  
Construction Period ◽  
Failure Patterns ◽  
Loading Tests ◽  
Two Sides

This paper proposes a novel U-shaped steel-encased concrete composite beam-girder joint (referred to herein as the novel composite beam-girder joint), in which the U-shaped beams at two sides (L and R) are inserted into a shaped sleeve, and the U-shaped girder and two U-shaped beams are connected by the shaped sleeve through welding. Compared with the traditional beam-girder joints, the novel composite beam-girder joints take advantage of easy construction, light weight, and short construction period. The failure patterns, load-strain and load-deflection curves, and strain distributions of the novel composite beam-girder joints were investigated through the static loading tests on two full-scale specimens, denoted as GBJ1 and GBJ2. The two specimens were varied in beam section reinforcements. Specimen GBJ2 was equipped with 3Ф16 additional bars in the U-shaped beams based on Specimen GBJ1. Test results show that the two specimens failed as the through arc cracks developed at the concrete slab interfaces. The additional bars can increase the bearing capacity slightly but will also increase the stress concentration on the bottom flange of the shaped sleeve, leading to the decrease of ductility for Specimen GBJ2. The slab effect is considered in the test and can thus reflect the actual stress state of the beam-girder joints well. This study can provide a reference for the design and application of beam-girder joints.

Mechanical Properties of Large Scale Confined Concrete

2011 ◽  
Vol 94-96 ◽  
pp. 1983-1988
Author(s):  
Jia Song ◽  
Zhen Bao Li ◽  
Yong Ping Xie ◽  
Xiu Li Du ◽  
Yue Gao
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Axial Compression ◽  
Large Scale ◽  
Plain Concrete ◽  
Concrete Columns ◽  
Confined Concrete ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Reinforcement Configuration

An experimental study was made of the mechanical properties of large scale confined concrete subjected to the axial compression test. Eleven tied concrete columns and six plain concrete prisms were tested. In the test, each specimen had the same transverse reinforcement configuration, and similar volumetric ratio of lateral steel, while different size. The test results in this paper indicate that the size of the specimen has no obvious relationship with the ultimate strength, however, it does affect the post-peak ductility to some extent. As a supplement to the experimental study, a finite element method was adopted to imitate the mechanical behavior of the confined concrete under axial compression. The results of the imitation in this paper indicate the confinement mechanism of large scale specimens.

scholarly journals Concept Map Technique as a New Method for Whole Text Translation

2017 ◽  
Vol 10 (4) ◽  
pp. 62
Author(s):  
Tamara Mohd Altabieri Krishan
Keyword(s):  
Traditional Method ◽  
English Language ◽  
Concept Map ◽  
Arabic Language ◽  
T Test ◽  
New Method ◽  
Test Results ◽  
Test Of Homogeneity ◽  
The Difference

This study discusses the use of concept map tool as a new method for teaching translation (from English language to Arabic language). This study comprised 80 students divided into two groups. The first group was taught the new vocabulary by using the concept tool method, whereas the second group was taught the new vocabulary by the traditional method. Pre-test and test of homogeneity was administered in order to ensure the equivalence of the students. During the training, the two groups were subjected to evaluation tests (first, second and final) in which the students were asked to summarize text into a paragraph by translation. The differences between the two methods were compared by using t-test. Results of pre-test indicated that the difference between the two groups was not significant and the scores were linearly distributed. Results of students’ scores between the two groups for the first exam was not significant, however, the difference between the two groups for second, final and total scores was significant. It was seen that the introduced method of text translation improves the student skills compared with the traditional method.

The Design of an Intelligent Tracing Car Controller

2011 ◽  
Vol 411 ◽  
pp. 283-286
Author(s):  
Dang Juan Li
Keyword(s):  
Analog Circuits ◽  
Processing Unit ◽  
Test Results ◽  
Physical Test ◽  
Tracking Process ◽  
Driver Circuit ◽  
Transistor Circuit ◽  
Intelligent Tracking

We focus on the design of an intelligent tracing car controller based on analog circuits. In this work, detectors, processing unit and driver module are acted as the Infrared tube, LM393 and the switch of transistor circuit respectively. The voltage comparison and filtering are finished after analyzing and processing the track information acquired. And the signal controls the driver circuit action. Therefore the intelligent tracking process was realized. The physical test results show that the design is simple, stable working and good following mark ability.

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