scholarly journals Experimental Study on the Shear Behavior of Bolted Concrete Blocks with Oblique Shear Test

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bo Meng ◽  
Hongwen Jing ◽  
Shengqi Yang ◽  
Yingchao Wang ◽  
Biao Li
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Normal Force ◽  
Concrete Block ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Failure Plane ◽  
Residual Shear Strength ◽  
Apparent Cohesion ◽  
Concrete Blocks

The shear behavior of concrete blocks reinforced by fully grouted bolts with different diameters was studied in this paper. More than 90 intact cubic samples (100 mm × 100 mm × 100 mm) with bolts ranging from 2 mm to 5 mm in diameter were tested at a constant stain rate of 0.5 mm/min. An oblique shear apparatus, which could simultaneously apply shear and normal force on tested samples at three slope angles (53°, 58°, and 63°) of a predetermined shear plane, was employed. The results indicate that the bolt has no evident influence on the shear behavior of intact concrete blocks at the prepeak shear strength stage. The bolt could significantly reduce the shear strength drop in the peak shear strength of the concrete block and contribute to reserving the residual shear strength of concrete blocks, especially at steep slope angles of the shear failure plane. The shear resistance provided by the bolt to the concrete block at the residual shear slip stage has a positive relationship with the diameter. The bolt with a larger diameter inflected in the vicinity of the shear failure plane of concrete block at the postpeak shear strength stage; additional normal force and direct shear resistance could still be persistently provided. Two empirical equations of the apparent cohesion and apparent internal angle of the bolted concrete block were obtained by linear regression considering rb, which is the ratio of the cross-sectional area of the bolt to that of the bolted concrete block.

scholarly journals Shear Behavior of Hollow Concrete Block Masonry with Precast Concrete Anti-Shear Blocks

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Xinlei Yang ◽  
Hanchen Wu ◽  
Jianxin Zhang ◽  
Hailiang Wang
Keyword(s):  
Shear Strength ◽  
Precast Concrete ◽  
Ductile Failure ◽  
Concrete Block ◽  
Shear Behavior ◽  
Shear Loading ◽  
Control Group ◽  
Double Shear ◽  
Shear Failures ◽  
Maximum Shear Strength

In order to improve the shear behavior of hollow concrete block masonry, precast concrete anti-shear blocks were proposed to enhance the shear strength of hollow concrete block masonry. Four groups of hollow concrete block masonry triplets with precast concrete anti-shear blocks were tested under shear loading, and their behaviors were compared with a control group. The results show that as the height of precast concrete anti-shear blocks increases, the shear strength of the masonry increases. The maximum shear strength of masonry triplets with precast concrete anti-shear blocks was 234.48 percent higher than that of the control specimens. The shear strength of masonry triplets was mainly determined by the failure of hollow concrete block unit. The majority of specimens exhibited double shear failures; however, these failures showed characteristics of ductile failure to a certain extent. Based on the experimental results, a equation for calculating the shear strength of masonry with precast concrete anti-shear blocks was proposed.

Influence of Stirrup Corrosion on Shear Strength of RC Beams

2012 ◽  
Vol 204-208 ◽  
pp. 3287-3293
Author(s):  
Xin Xue ◽  
Hiroshi Seki ◽  
Yu Song
Keyword(s):  
Shear Strength ◽  
Mass Loss ◽  
Local Maximum ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Maximum Mass ◽  
Rc Beams ◽  
Load Carrying ◽  
Maximum Mass Loss

There have been few reports on shear behavior of reinforced concrete (RC) beams with corroded stirrups, and the influence of stirrup corrosion has yet to be identified. Given this background, experience was carried out to investigate the shear behavior of RC beams containing corroded stirrups. Investigation results indicate that if the percentage local maximum mass loss is below 35%, there is little influence on the load-carrying mechanism. The concrete shear resistance seems to change little and the shear capacity can be calculated by just taking into consideration the reduction in stirrup shear resistance. It is also found that the anchorage conditions of the stirrups have a predominant influence on the shears of RC beams.

scholarly journals EXPERIMENTAL INVESTIGATION OF MECHANICAL PROPERTIES OF SOLID CONCRETE BLOCK MASONRY EMPLOYING DIFFERENT MORTAR RATIOS

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Muhammad Rizwan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Research Work ◽  
Concrete Block ◽  
Unit Weight ◽  
Three Samples ◽  
Individual Unit ◽  
Concrete Blocks

This research work aims to investigate experimentally the mechanical properties of solid concrete blocks as an individual unit and assembly (block masonry) employing different mortar mix ratios. The material properties of the concrete block unit, such as compressive strength and unit weight were explored by taking three samples from the four local factories. The block masonry assemblages were subjected to various load patterns for the evaluation of compressive strength, diagonal tensile strength and shear strength. For the bond, four types of mortars i.e., cement – sand (1:4), cement – sand (1:8), cement – sand – khaka (1:2:2) and cement – sand – khaka (1:4:4) were used in the joints of concrete block masonry assemblages. (Khaka is a by-product formed in the stone crushing process). For each type of mortar, three samples of block masonry were fabricated for compressive strength, shear strength and diagonal tensile strength, and tested in the laboratory. It is observed that the replacement of sand by khaka enhanced the mechanical properties of masonry.

scholarly journals Experimental Investigation of the Shear Behavior of a Concrete Beam without Web Reinforcements Using External Vertical Prestressing Rebars

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Xingwei Xue ◽  
Xuan Wang ◽  
Xudong Hua ◽  
Meizhong Wu ◽  
Longqing Wu ◽  
...  
Keyword(s):  
Compressive Stress ◽  
Shear Failure ◽  
Concrete Beams ◽  
Shear Crack ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Shear Cracks ◽  
Web Reinforcement ◽  
Shear Performance

The shear performance of concrete beams is known to be an important mechanical feature; hence, enhanced shear resistance is critical for determining a beam’s performance in terms of security and service life. This paper presents a study on the shear behavior of concrete beams without web reinforcement strengthened by external vertical prestressing rebars (EVPRs). Experimental data were obtained from seven test beams with varying influencing factors (stirrup ratio ρsEP, arrangement spacing s, prestressing force Fp, and compressive stress degree γp of the EVPRs) to determine their effects on the shear behavior. The results reveal that the EVPRs can significantly improve the shear capacity and ductility of concrete beams without web reinforcement. Furthermore, the failure mode is changed from brittle diagonal tension to relatively ductile shear compression, and the flexural cracks and shear cracks are more fully developed. The shear capacity becomes enhanced as the ρsEP and γp are increased; vertical compressive stress provided by the EVPRs can reduce the principal tensile stress of the concrete structure to prevent the shear cracking and enhance the shear resistance of the concrete. Meanwhile, in the stage from the formation of the critical shear crack (CSC) to the shear failure, the EVPRs can be used as stirrups to share the shear load. It can be concluded that EVPRs can effectively improve the shear performance of concrete beams.

Back Analysis of Landslide Deposit Basal Failure Plane Residual Shear Strength

IACGE 2013 ◽  
2013 ◽  
Author(s):  
N. Matasovic ◽  
C. Conkle ◽  
A. F. Witthoeft ◽  
A. Stern ◽  
T. Hadj-Hamou
Keyword(s):  
Shear Strength ◽  
Back Analysis ◽  
Failure Plane ◽  
Residual Shear Strength ◽  
Landslide Deposit

scholarly journals Influence of the Diatomite Specie on the Peak and Residual Shear Strength of the Fine-Grained Soil

2021 ◽  
Vol 11 (4) ◽  
pp. 1352
Author(s):  
Carlos J. Slebi-Acevedo ◽  
Daniel A. Zuluaga-Astudillo ◽  
Juan C. Ruge ◽  
Daniel Castro-Fresno
Keyword(s):  
Shear Strength ◽  
Physical And Mechanical Properties ◽  
Friction Angle ◽  
Shear Resistance ◽  
Strength Test ◽  
Residual Shear Strength ◽  
Shear Strength Test ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Mexican Species

Diatomite is a powdering mineral mainly composed of diatom microfossils present in marine and lacustrine soils, which influences their physical and mechanical properties. Although many articles have been found in the literature concerning the influence of diatomite in the overall behavior of natural soils, few research efforts have been carried out to evaluate the influence of the diatom microfossil species on their shear resistance. Therefore, in this research, the influence of the diatomite species and the content in the peak and the residual shear strength of diatomite-fine grained soil mixtures was analyzed using the annular shear strength test. Scanning electron microscopy (SEM) and Atterberg limits were also carried out as additional tests to explain the interlocking effect between the microfossils and the soil. Overall, both diatomite species increased both peak and residual shear strength of the soil similar to dense sands. Nevertheless, the Mexican species reveal higher friction angle values compared with Colombian species.

Effect of roughness on shear behavior of red clay – concrete interface in large-scale direct shear tests

2015 ◽  
Vol 52 (8) ◽  
pp. 1122-1135 ◽  
Author(s):  
Xiaobin Chen ◽  
Jiasheng Zhang ◽  
Yuanjie Xiao ◽  
Jian Li
Keyword(s):  
Surface Roughness ◽  
Shear Strength ◽  
Large Scale ◽  
Shear Failure ◽  
Friction Angle ◽  
Confining Pressure ◽  
Shear Behavior ◽  
Interfacial Shear ◽  
Red Clay ◽  
Direct Shear Tests

Few studies have focused on evaluating regular surface roughness and its effect on interfacial shear behavior of the red clay – concrete interface. This paper presents the results of a series of laboratory large-scale direct shear tests conducted using different types of red clay – concrete interfaces. The objective is to examine the effect of surface roughness on these types of soil–concrete interfaces. In the smooth-interface tests, the measured peak and residual shear strength values are very close to each other, with no observed shear dilation. The surface roughness is found to have a remarkable effect on the interfacial shear strength and shear behavior, with the shear strength increasing with increased surface roughness level. The shear dilation is likely to occur on rougher interfaces under lower confining pressure due to the behavior of compressed clay matrices. Owing to the clay matrix’s cohesion and friction, the interfacial shear strength on rough interfaces consists of cohesive and frictional forces between the clay and concrete surfaces. The friction angle value is observed to fluctuate between the clay’s friction angle and the smooth interface’s friction angle. This can be related to the position change of the shear failure slip plane. The confining pressure and surface roughness could change the shear failure plane’s position on the interface. Furthermore, the red clay – structure interface is usually known as the weakest part in the mechanical safety assessment.

scholarly journals Experimental Study on Mechanical Properties of Interface between Basalt Fiber-Reinforced Polymer/Glass Fiber-Reinforced Polymer Composite Cement Plate and Concrete

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Lifeng Zhang ◽  
Hui Liu ◽  
Wenqiang Li ◽  
Hangjun Liu ◽  
Xuehui An ◽  
...  
Keyword(s):  
Shear Strength ◽  
Failure Modes ◽  
Shear Failure ◽  
Concrete Strength ◽  
Concrete Block ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Bond Slip ◽  
Reinforced Polymer ◽  
Composite Samples

The bonding behaviors of the plate-concrete interface of a composite structure consisting of a concrete block in the middle and two cement plates at both sides play a key role in its overall mechanical performance. In this paper, the authors conduct 3 groups of push-out shear tests on a total of 39 composite samples to assess the bonding performance. The influence of the FRP cement plates, the concrete strength, and the ribs installed in the cement plate on the interfacial shear strength, the relative bond-slip, strain, and the failure modes of the composite samples is recorded and analyzed. The results show that (1) the shear strength and bond-slip performance of the interface are largely improved if the GFRP/BRRP cement plates are used; (2) shear strength of the interface increases with the concrete strength, while the deformation behaviors show no significant improvement; (3) an inclusion of the ribs to the interface enhances the shear strength and shear stiffness but decreases the maximum relative slip at failure; (4) most of the samples present the shear failures along the interface; however, the bending shear failure prior to the interface shear failure is also observed on the concrete block for low concrete strength samples and the samples with ribs; and (5) regression method is used to develop a constitutive model of the stress-slip at the interface to describe the relationship between the shear strength with the cement plates, the concrete strength, and ribs.

scholarly journals Experience with Shear Frames

1983 ◽  
Vol 29 (103) ◽  
pp. 485-491 ◽  
Author(s):  
R. Perla ◽  
T. M. H. Beck
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Normal Stress ◽  
Shear Failure ◽  
Statistical Data ◽  
Failure Plane ◽  
Shear Frame ◽  
Strength Distributions

AbstractThe shear frame is a simple in situ device for indexing the shear strength of thin weak layers. The index is sensitive to shear-frame geometry, rate-of-pull, and shear-frame mass. It is time-consuming to carefully align the device on the Gleitschicht (shear failure plane) in a slab avalanche zone. The ratio shear frame index/shear stress of the Gleitschicht has a high variance, and may not be a fundamental measure of slab avalanche stability. Corrections for the normal stress on the Gleitschicht reduce the variance only slightly. Despite these limitations, the shear frame is a useful tool for gathering statistical data on strength distributions and anisotropies of the Gleitschicht until a more fundamental technique is developed.

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