Mechanical Properties of Fiber Reinforced Lime-Based Mortars Evaluated from Four-Point Bending Test

2016 ◽  
Vol 821 ◽  
pp. 526-531
Author(s):  
Michal Přinosil ◽  
Petr Kabele
Keyword(s):  
Thermal Effects ◽  
High Performance ◽  
Correlation Method ◽  
Image Correlation ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Four Point Bending ◽  
High Performance Fiber ◽  
Bending Behavior ◽  
Four Point Bending Test

In the study, the bending behavior of high-performance fiber reinforced lime-based mortars is experimentally investigated using four-point bending test. From the experimental data, the influence of the mortar’s composition on its stiffness, cracking strength and ultimate strength are investigated. It is also studied, whether the response has strain-softening or strain-hardening character and whether the material exhibits multiple cracking. Such behavior is very important for the durability of the material, because it allows carrying load during imposed deformations (due to thermal effects, movements of foundations, seismicity, etc.). The number of formed cracks is examined using digital image correlation method. The mortar composition is considered with two types of binder (pure lime, lime-metakaolin), with two types of polyvinyl alcohol fibers in four volume fractions (0.5÷2.0%). As the reference, we consider two sets of specimens made of plain mortar without fiber reinforcement.

scholarly journals Experimental and Numerical Investigation on Shear Retrofitting of RC Beams by Prefabricated UHPFRC Sheets

2016 ◽  
Vol 2 (5) ◽  
pp. 168-179
Author(s):  
Kian Aghani ◽  
Hassan Afshin
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Fem Analysis ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Externally Bonded ◽  
High Performance Fiber ◽  
Bending Capacity

Different methods are used for retrofitting RC members. One of the new methods in this field is using externally bonded fiber-reinforced Concrete (FRC) sheets in order to increase RC member’s shear and flexural strength. In this study, applicability of ultra-high performance fiber-reinforced concrete sheets in shear and flexural retrofitting of RC beams was investigated. In total, eight RC beams (dimensions 10×20×150 cm) with two different bending capacity and lack of shear strength were used and were tested in 3-points bending test. Of these, four were control beams and four were retrofitted with laterally bonded UHPFRC sheets. Dimensions of the sheets used for retrofitting were (3×15×126 cm). Also FEM analysis was used to model the effect of The method. the results show that this method can be well used for retrofitting RC beams. In this method the way of connecting sheets to beam’s surfaces has a fundamental role in behavior of retrofitted beams.

Relationship between Fiber Orientation and Flexural Strength in Ultra-High-Performance Fiber-Reinforced Concrete Panels

2014 ◽  
Vol 629-630 ◽  
pp. 71-78 ◽  
Author(s):  
Bo Zhou ◽  
Yuichi Uchida
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Fiber Orientation ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Three Point Bending ◽  
Concrete Panels ◽  
High Performance Fiber

In this study, the influence of fiber orientation on the flexural strength of ultra-high-performance fiber-reinforced concrete (UHPFRC) was examined. To this end, a circular UHPFRC panel measuring φ1,200 × 50 mm was cast from its center, and test specimens measuring 50 × 50 × 200 mm with 10 mm notches for three-point bending tests were cut from it with angles of 0, 30, 60 and 90° between the specimen axis and the radial direction of the panel. After the bending test, fiber orientation on the ruptured surfaces of the specimens was observed. The flexural strengths of the specimens cut at angles of 60, 30 and 0° were 80, 40 and 10% of that for the specimen cut at an angle of 90°. It was also found that the flexural strength of specimens cut from a rectangular panel cast from its center point depended on their original positions and orientation within the panel. Similar fiber orientation characteristics were found in the circular and rectangular panels.

Test Methods for Silicon Die Strength

2006 ◽  
Vol 128 (4) ◽  
pp. 419-426 ◽  
Author(s):  
M. Y. Tsai ◽  
C. H. Chen ◽  
C. S. Lin
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Test Methods ◽  
Biaxial Stress ◽  
Bending Test ◽  
Published Data ◽  
Failure Strength ◽  
Surface Conditions ◽  
Four Point Bending ◽  
Four Point Bending Test

Recently, the 3D or stacked-die packages become increasingly popular for packaging ICs into a system or subsystem to satisfy the needs of low cost, small form factor, and high performance. For the applications of these packages, IC silicon wafers have to be ground to be relatively thin through the wafer-thinning processes (such as grinding, polishing, and plasma etching). The strength of dies has to be determined for the design requirement and reliability assurance of the packages. From the published data, there still exist some issues, including a large scatter existed in die strength data and difficulties in differentiating the causes of the low strength between from the wafer grinding and from wafer sawing by either the three-point bending or four-point bending test. The purposes of this study are to develop new, reliable, and simple test methods for determination of die strength, in order to improve the data scatter, and to provide a solution for differentiating the factors that affect the variability of die strength for finding out the causes of the weakness of the die strength. In this study, two new test methods, point-loaded circular plate with simple supports test (PLT-I) and point-loaded plate on elastic foundation test (PLT-II), are proposed and then evaluated by testing two groups of silicon dies with different surface conditions. The surface conditions (roughness) of the specimens are determined by atomic force microscopy and correlated to failure strength. The failure forces from both tests have to be modified by using maximum stress obtained from theories or finite element analyses to obtain the failure strength. The test results are compared to each other and further with a widely used four-point bending test. The results suggest that, unlike the four-point bending test suffering the chipping effect, both methods provide very consistent data with a small scatter for each group of specimens and can be used for identifying the effect of surface grinding (roughness) on the die strength. It is also shown that the die strength is highly dependent on the surface roughness. Accordingly, these two methods can provide not only a (biaxial) stress field similar to temperature-loaded die in the packages, but also simple, feasible, reliable, and chipping-free tests for silicon dies of dummy or real IC chips, without strict geometrical limitation, such as beam-type geometry for the three-point or four-point bending test.

Modeling of Deformation and Fracture of Concrete Structures with FRP Reinforcement

2015 ◽  
Vol 752-753 ◽  
pp. 685-688
Author(s):  
Andrey Benin ◽  
S.G. Semenov ◽  
Artem S. Semenov
Keyword(s):  
Image Correlation ◽  
Bending Test ◽  
Four Point Bending ◽  
Reinforced Plastic ◽  
Deformation And Fracture ◽  
Different Types ◽  
Loading Case ◽  
Frp Reinforcement ◽  
Four Point Bending Test ◽  
Frp Bars

Carrying capacity and fracture modes of concrete beams reinforced by different types of fiber reinforced plastic (FRP) bars are analyzed experimentally and numerically. The four-point-bending test is used as a typical loading case for this purpose. Synchronous registration of loading level, displacements and strains is performed by using InstronTM servohydraulic machine, LVDT sensors, strain gauges and digital image correlation Vic3DTM system. The experimental data and results of finite element simulations are compared and discussed.

scholarly journals Flexural Behavior of Ultra-High Performance Fiber Reinforced Concrete Scale Tunnel Segment

2018 ◽  
Vol 38 ◽  
pp. 03037
Author(s):  
Kun Ni ◽  
Fa Sheng Zhang ◽  
Yun Xing Shi ◽  
Yan Gang Zhang ◽  
Jing Bin Shi
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Ultimate Load ◽  
Fiber Reinforced Concrete ◽  
Flexural Behavior ◽  
Fiber Reinforced ◽  
Flexural Performance ◽  
Four Point Bending ◽  
High Performance Fiber ◽  
Elastic Stage

To reduce the weight of precast tunnel segment, ultra-high performance fiber reinforced concrete (UHPFRC) was studied to cast the segment. The flexural performance of UHPFRC scale tunnel segments were tested in this work. The weight of the UHPFRC thinner scale tunnel segment was only 80% of reinforced concrete (RC) segment. The segments were loaded as per CJJ/T 164-2011, and the four-point bending system was used. The results showed that the cracking load increased 50%, and 0.2 mm crack width load increased 22%, and the yield load increased 11%, and the ultimate load only decreased 1%. The stiffness of elastic stage of UHPFRC segment looked the same compared to RC segment. In a word, the UHPFRC thinner segments showed excellent flexural performance beyond the traditional RC segment.

scholarly journals Influence of Secondary Reinforcement on Behaviour of Corbels with Various Types of High-Performance Fiber-Reinforced Cementitious Composites

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4159 ◽  
Author(s):  
Nasuha Md Zin ◽  
Amin Al-Fakih ◽  
Ehsan Nikbakht ◽  
Wee Teo ◽  
Mahmoud Anwar Gad
Keyword(s):  
High Performance ◽  
Load Capacity ◽  
Secondary Reinforcement ◽  
Bending Test ◽  
Cementitious Composites ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
High Performance Fiber ◽  
Fiber Reinforced Cementitious Composites

An experimental study is conducted to determine the influence of secondary reinforcement on the behaviour of corbels fabricated with three different types of high-performance fiber-reinforced cementitious composites, including engineered cementitious concrete (ECC); high-performance steel fiber-reinforced composite (HPSFRC); and hybrid fiber-reinforced composite (HyFRC). Two shear span-to-depth ratios (a/d = 0.75 and 1.0) are explored. The mechanical properties of the composites in terms of tensile, compressive, and flexural strengths are investigated. Next, the structural behaviour of the high-performance cementitious composite corbels in terms of ultimate load capacity, ductility, and failure modes under the three-point bending test are investigated. The secondary reinforcement is proven to significantly affect stiffness and ultimately load capacity of all three high-performance composite corbels with an aspect ratio of 0.75. However, the secondary reinforcement was more impactful for the HPSFRC corbels, with 51% increase of ultimate strength. Moreover, in terms of damage, fewer cracks occurred in ECC corbels. HPSFRC corbels displayed the highest level of ductility and deformation capacity compared to the other specimens. The results were comparatively analyzed against the predicted results using truss and plastic truss models which provided relatively reliable shear strength.

Novel Test Methods for Die Strength

2005 ◽  
Author(s):  
M. Y. Tsai ◽  
C. H. Chen ◽  
C. S. Lin
Keyword(s):  
High Performance ◽  
Axial Stress ◽  
Test Methods ◽  
Bending Test ◽  
Published Data ◽  
Failure Strength ◽  
Element Analysis ◽  
Surface Conditions ◽  
Four Point Bending ◽  
Four Point Bending Test

Recently, the 3-D or stacked-die packages are increasingly popular for packaging ICs into a system or subsystem to satisfy the needs of low cost, small form factor, and high performance. For the applications of these packages, IC wafers have to be ground to be relatively thin through the wafers thinning processes (such as grinding, polishing, and plasma etching). The strength of dies has to be determined for the design requirement and thus assuring reliability of the packages. From the published data, there still exist some issues including a large scatter existed in die strength data, and difficulties with differentiating the causes of the low strength from the grinding or die sawing either by three-point bending or four-point bending test. The purposes of this study is to develop new, reliable and simple test methods for determination of die strength to improve the data scatter and also provide a solution for differentiating the factors that affect the variability of die strength, in order to find out the causes of the weakness of the die strength. In this study, two new test methods, point-loaded circular plate with simple supports test (PLT-I) and point-loaded plate on elastic foundation test (PLT-II) are proposed and evaluated by testing two groups of silicon dies with different surface conditions. The surface conditions (roughness) of the specimens are determined by atomic force microscopy and correlated to failure strength. The failure forces from both tests have to be modified by using maximum stress obtained from theory or finite element analysis to get the failure strength. The test results are compared with each other and further with widely-used four-point bending test. The results suggest that, unlike the four-point bending test, both methods provide very consistent data with a small scatter for these two groups of specimens, and indicated the die strength is highly dependent on the surface roughness. Accordingly, these two methods can provide not only a (bi-axial) stress field similar to temperature-loaded die in the packages, but also simple, feasible, reliable and chipping-free tests for silicon dies of dummy or real IC chips, without strict geometrical limitation, such as beam-type geometry for three-point or four-point bending test.

Inverse characterisation of gradient distribution of the modulus of bamboo using a four-point bending test

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xianzhi Gao ◽  
Guangyan Liu ◽  
Lu Wang ◽  
Yanan Yi ◽  
Guang Lin ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Model Updating ◽  
Volume Fraction ◽  
Image Correlation ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Gradient Distribution ◽  
Outer Skin ◽  
Four Point Bending ◽  
Four Point Bending Test

AbstractAs a natural graded material, bamboo has gradually increasing elastic modulus along the radial direction from the inner to the outer skin. Accurate measurement of the modulus distribution plays an important role in bamboo-based structural design. However, it is difficult to characterise this modulus distribution by using conventional testing approaches on bamboo slices. A more effective method was developed in this study for the inverse identification of gradually varying material properties. The method is based on the digital image correlation and finite element model updating techniques. The radial distribution of the elastic modulus of bamboo was obtained through only one four-point bending test. The inversely identified modulus distribution was verified through uniaxial tensile tests on sliced bamboo strips and microscopic observation of the volume fraction distribution of its vascular bundle. The results showed that the elastic modulus of the bamboo material decreased from the outer skin (20 GPa) to the inner skin (2 GPa), which is in good consistence with the tensile test results on sliced specimens.

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