scholarly journals Experimental Study of the Shear Performance of Scrap Tire-Granular Material Composite Columns

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Fengchi Wang ◽  
Xiaomei Nie ◽  
Hanyu Zhao ◽  
Haiming Hu
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Lateral Displacement ◽  
Vertical Force ◽  
Scrap Tire ◽  
Stress Strain ◽  
Composite Columns ◽  
Failure Patterns ◽  
Loading Mode ◽  
Shear Performance

Scrap tires filled with granular materials can be used for geotechnical engineering. However, when subjected to earthquakes and other conditions, shear failure occurs between the tires. In this paper, eight groups of tire-sand composite columns are prepared and tested under shear strength tests. Different vertical forces, sand densities, and loading modes are considered to investigate the shear performance. The failure patterns, load-displacement curves, and stress-strain curves are observed. The results show that the shear failure of composite undergoes three typical stages: overall flexural lateral displacement, transverse compression, and relative interfacial slip. Under monotonic loading, the restriction of the transverse deformation of the composite column is enhanced with increasing vertical force. The overall antidisturbance ability of the composite is enhanced with increasing sand density. The cyclic loading mode can improve the lateral stiffness of the tire-sand composite. The relative motion between the tire-sand interfaces has two forms: elastic creep and interface sliding. Under the hoop effect of the tire, the pores between the particles produce a pseudocohesive force, which causes the shear strength of the tire-sand composite to be higher than that of common sand. A formula is obtained to describe the stress-strain variations in the composite under different vertical forces.

Shear Strength of Concrete and Gypsum Composite Walls

2013 ◽  
Vol 368-370 ◽  
pp. 976-983 ◽  
Author(s):  
Kang Liu
Keyword(s):  
Shear Strength ◽  
Glass Fiber ◽  
Shear Failure ◽  
Design Procedure ◽  
Green Product ◽  
Ultimate Shear Strength ◽  
Glass Fiber Reinforced ◽  
Shear Performance ◽  
Save Energy ◽  
Composite Walls

Gypsum walls are a green product that helps to save energy and protect the environment. This paper investigates the shear strength of glass fiber reinforced gypsum (GFRG) walls fully or partially filled with concrete in the hollow cores. Eight full scale GFRG walls were tested. The shear performance of the tested walls, including the shear failure mode, hysteresis responses, the ultimate shear strength were studied in the paper. A design procedure for the shear strength of the concrete filled GFRG walls is developed.

scholarly journals Experimental Study and Failure Criterion Analysis on Combined Compression-Shear Performance of Self-Compacting Concrete

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 713 ◽  
Author(s):  
Jingrong Wang ◽  
Faxiang Xie ◽  
Chuanlong Zhang ◽  
Jing Ruan
Keyword(s):  
Residual Stress ◽  
Shear Strength ◽  
Axial Compression ◽  
Failure Modes ◽  
Shear Failure ◽  
Experimental Results ◽  
Compression Stress ◽  
Self Compacting Concrete ◽  
Cohesive Stress ◽  
Shear Performance

To investigate the combined compression-shear performance of self-compacting concrete (SCC), eight groups of concrete specimens under different axial compression ratios were designed, and the composite performance under different axial stresses was carried out by hydraulic servo machine. The uniaxial and tensile splitting strength of SCC were also included in the study. The failure modes of SCC were presented, discussed, and compared with normal concrete (NC). The characteristic points of stress-strain curves of SCC specimens from the experiments were extracted and analyzed under different axial compression stress. Based on the experimental results, the shear strength of compression-shear load was divided into cohesive stress and residual friction stress. The variation of residual stress and cohesive stress under the combined compression-shear stress was analyzed, and the relationship was obtained by numerical regression. Research results indicated that the residual stress increases linearly with the compression stress while the cohesive stress increased at first and then decreased. The research found that the friction coefficient of SCC was much smaller than NC due to the lack of interlocking effect. Utilizing the compression-shear strength of SCC, the material failure criteria of SCC were proposed from the view of shear failure strength and octahedral stress space, which could fit the experimental results confidently following the mathematical regression analysis. The comparison with data from other literature shows favorable consistence with the obtained criteria. The results of the study could be beneficial complement in engineering practices where SCC was applicable.

Shear Strength of Void Slab with Polystyrene Forms

2012 ◽  
Vol 217-219 ◽  
pp. 626-629
Author(s):  
Seung Hun Kim
Keyword(s):  
Shear Strength ◽  
Precast Concrete ◽  
Test Results ◽  
Ultimate Shear Strength ◽  
Construction Period ◽  
Failure Patterns ◽  
Shear Performance ◽  
Experimental Works ◽  
Resistance Performance ◽  
Concrete Deck

Void slab systems with polystyrene form and precast concrete deck have been used to reduce the construction period and the self-weight of the slab. This paper presents experimental works on the shear of the void slabs. Four specimens were tested. The main parameters of experiments were the type of polystyrene forms and the thickness of slab. Shear performances of void slabs were evaluated on the basis of failure patterns, load-displacement curves, and ultimate shear strengths. Based on the test results, the unidirectional void slabs had the best shear resistance performance when they used PF2 type of polystyrene forms. For all specimens that failed due to shear, ultimate shear strength was 52% or higher than nominal shear strength by ACI318-08. This indicates that void slabs have a sufficient shear performance in the truss bar arrangement direction

scholarly journals Effect of Microstructures on the Shear Strength of Larix kaempferi

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 830
Author(s):  
Mingyue Li ◽  
Shuangbao Zhang ◽  
Yurong Wang ◽  
Haiqing Ren
Keyword(s):  
Cell Wall ◽  
Shear Strength ◽  
Failure Mode ◽  
Wall Thickness ◽  
Shear Failure ◽  
Microfibril Angle ◽  
Cell Wall Thickness ◽  
Larix Kaempferi ◽  
Significant Difference ◽  
Shear Performance

Shear strength is important for the application of Larix kaempferi (Lamb) Carr. The structural difference between earlywood and latewood of Larix kaempferi affects its mechanical properties, especially shear strength. The microstructures of earlywood and latewood in Larix kaempferi, however, are different. In this study, we investigated the shear strength and shear failure mode in the RL direction of 40 Larix kaempferi specimens. The results demonstrated that the initial crack appears in any location of a growth ring, whereas shear failure is concentrated in earlywood, as well as the junction between earlywood and latewood. The destruction of earlywood is the tear destruction, whereas when the destruction happened in the junction of earlywood and latewood, one to three earlywood cells usually adhered to latewood. At the cell wall level, the shear failure of earlywood was mostly observed in the direction of the microfibril angle (MFA). When the crack occurs in latewood, the destruction of latewood also occurs in the intercellular layer and preserves the complete morphology of tracheids. When destruction occurs in the wood ray, the ray cells detach intact from the tracheids. The failure mode is determined by the microstructure of earlywood and latewood. Our research suggests that the density, cell wall thickness, and MFA have significant differences between earlywood and latewood. The earlywood was found to have an MFA of 25.4°, a cell wall thickness of 6.36 µm, and a density of 0.39 g/cm3. The MFA, cell wall thickness, and density of latewood density were 17.60°, 12.37 µm, and 0.78 g/cm3, respectively. However, there was no significant difference found in the crystallinity between the earlywood (43.97%) and latewood (42.79%). The correlation between the microstructures and shear strength showed that earlywood with a thin cell wall, large MFA, and low density had poor shear performance, while the latewood with a thicker tracheid, smaller MFA, and higher density had better shear performance. Therefore, when shear failure occurred, it occurred in earlywood. We thus deduced that the MFA, cell wall thickness, and density of earlywood synergically affect the shear strength in the RL direction of L. kaempferi.

Numerical Study on Shear Strength and Failure Pattern of Jointed Rock under Shear Testing

2005 ◽  
Vol 297-300 ◽  
pp. 2617-2622
Author(s):  
Hou Quan Zhang ◽  
Li Song ◽  
Junjie Liu ◽  
Tao Xu ◽  
Xiong Chen ◽  
...  
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Numerical Study ◽  
Process Analysis ◽  
Failure Process ◽  
Failure Surface ◽  
Shear Loading ◽  
Failure Pattern ◽  
Failure Patterns ◽  
Joint Separation

The purpose of this paper is to investigate shear strength and failure pattern of rock containing two parallel open joints with different horizontal separations using RFPA2D (rock failure process analysis) code. Specimens are placed in a direct shear box. The upper is invariably loaded with normal stress 0.15MPa, the left is controlled by a constant increasing horizontal displacement 0.002mm/step. The whole shear failure process is visually represented and the failure pattern in reasonable accordance with previous experimental results is obtained. In general, only mixed mode (tensile and shear) is observed for the failure pattern in the numerical tests. Tensile cracks initiate from the tips of pre-existing joints respectively with an initiation angle of about 45°, then propagate towards another joint in a single stria; Shear cracks occur in the further process and the main direction of shear failure surface is roughly parallel to shear loading. The failure pattern of bridged rock is mainly controlled by the joint separation and the roughness of wavy shear failure surface is different, which is mostly influenced by the joint separation in the same way. The peak shear load, related to the failure patterns, decreases with the increase of joint separation, but the shear strength of intact rock is invariable.

scholarly journals Experimental and Numerical Studies on the Structural Performance of a Double Composite Wall

2021 ◽  
Vol 11 (2) ◽  
pp. 506
Author(s):  
Sun-Jin Han ◽  
Inwook Heo ◽  
Jae-Hyun Kim ◽  
Kang Su Kim ◽  
Young-Hun Oh
Keyword(s):  
Shear Strength ◽  
Precast Concrete ◽  
Structural Performance ◽  
Behavioral Characteristics ◽  
Element Analysis ◽  
Numerical Studies ◽  
Shear Performance ◽  
Flexural Analysis ◽  
Composite Wall ◽  
Current Code

In this study, experiments and numerical analyses were carried out to examine the flexural and shear performance of a double composite wall (DCW) manufactured using a precast concrete (PC) method. One flexural specimen and three shear specimens were fabricated, and the effect of the bolts used for the assembly of the PC panels on the shear strength of the DCW was investigated. The failure mode, flexural and shear behavior, and composite behavior of the PC panel and cast-in-place (CIP) concrete were analyzed in detail, and the behavioral characteristics of the DCW were clearly identified by comparing the results of tests with those obtained from a non-linear flexural analysis and finite element analysis. Based on the test and analysis results, this study proposed a practical equation for reasonably estimating the shear strength of a DCW section composed of PC, CIP concrete, and bolts utilizing the current code equations.

scholarly journals An Experimental Study on Mechanical Behavior of Parallel Joint Specimens under Compression Shear

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Fei Wang ◽  
Ping Cao ◽  
Yu Chen ◽  
Qing-peng Gao ◽  
Zhu Wang
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Failure Mode ◽  
Shear Failure ◽  
Strain Curve ◽  
Shear Loading ◽  
Plane Shear ◽  
Joint Spacing ◽  
Dip Angle ◽  
Joint Inclination

In order to investigate the influence of the joint on the failure mode, peak shear strength, and shear stress-strain curve of rock mass, the compression shear test loading on the parallel jointed specimens was carried out, and the acoustic emission system was used to monitor the loading process. The joint spacing and joint overlap were varied to alter the relative positions of parallel joints in geometry. Under compression-shear loading, the failure mode of the joint specimen can be classified into four types: coplanar shear failure, shear failure along the joint plane, shear failure along the shear stress plane, and similar integrity shear failure. The joint dip angle has a decisive effect on the failure mode of the specimen. The joint overlap affects the crack development of the specimen but does not change the failure mode of the specimen. The joint spacing can change the failure mode of the specimen. The shear strength of the specimen firstly increases and then decreases with the increase of the dip angle and reaches the maximum at 45°. The shear strength decreases with the increase of the joint overlap and increases with the increase of the joint spacing. The shear stress-displacement curves of different joint inclination samples have differences which mainly reflect in the postrupture stage. From monitoring results of the AE system, the variation regular of the AE count corresponds to the failure mode, and the peak value of the AE count decreases with the increase of joint overlap and increases with the increase of joint spacing.

scholarly journals Cyclic Shear Performance of Reinforced Concrete Columns Strengthened by External Steel Rods

2021 ◽  
Vol 13 (23) ◽  
pp. 13224
Author(s):  
Hyeong-Gook Kim ◽  
Yong-Jun Lee ◽  
Kil-Hee Kim
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Analytical Approach ◽  
Concrete Columns ◽  
Loading Test ◽  
Rc Structures ◽  
Cyclic Shear ◽  
Flexural Failure ◽  
Shear Performance ◽  
Strengthening Method

This study presents a strengthening method for reinforced concrete (RC) columns. The proposed method, which consists of a pair of steel rods, two reverse-threaded couplers, and four corner blocks, is feasible and straightforward. A quasi-static cyclic loading test was performed on the columns externally strengthened by the steel rods. It was found that the corner blocks and the external steel rods with a low prestress level effectively confined the concrete on the compression side of plastic hinges, which eventually induced flexural failure with a ductility higher than three in the strengthened columns. In addition, an analytical approach to predict the shear strength and ultimate flexural strength of the externally strengthened columns was applied. The comparison of analytical and experimental results showed that the analytical approach provided highly accurate predictions on the maximum strength and the failure mode of the externally strengthened columns. It is expected that the application of the proposed method will improve the seismic performance of damaged or deteriorated RC structures, thereby increasing their lifespan expectancy and sustainability.

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