Experimental Study on Shear Behavior of Hybrid Fiber Reinforced High Performance Concrete Deep Beams

2012 ◽  
Vol 166-169 ◽  
pp. 664-669
Author(s):  
Sheng Bing Liu ◽  
Lihua Xu
Keyword(s):  
Shear Strength ◽  
Aspect Ratio ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Shear Behavior ◽  
Calculation Formula ◽  
Hybrid Fiber ◽  
Deep Beams ◽  
Vertical Reinforcement

In order to investigate the effect of steel fiber and polypropylene fiber on shear behavior of HPC deep beams, the shear tests were conducted on 18 different groups of deep beams with steel fiber and polypropylene fiber and 2 groups of HPC deep beams without fiber according to the orthogonal experiment. 6 factors, including the shape of steel fiber, the volume fraction of steel fiber, the aspect ratio of steel fiber, the volume fraction of polypropylene fiber, the ratio of web horizontal reinforcement and the ratio of web vertical reinforcement, were compared by direct-viewing analysis. Results illuminate that hybrid fibers greatly increase the diagonal cracking strength and shear strength of HPC deep beams. The aspect ratio of steel fiber plays the most important role in diagonal cracking strength whereas the ratio of web vertical reinforcement has minimum effect. Meanwhile the ratio of web horizontal reinforcement plays the most important role in shear strength whereas the volume fraction of polypropylene fiber has minimum effect. An anti-cracking capacity for inclined section calculation formula and a shear bearing capacity calculation formula for hybrid fiber reinforced HPC deep beams are put forward based on current code. Meantime test verification is carried out and the calculated results are satisfied.

scholarly journals Research on compressive strength of hybrid fiber reinforced concrete based on orthogonal design

2021 ◽  
Vol 261 ◽  
pp. 02019
Author(s):  
Tu-Sheng He ◽  
Meng-Qian Xie ◽  
Yang Liu ◽  
San-Yin Zhao ◽  
Zai-Bo Li
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Prediction Model ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Concrete Compressive Strength ◽  
Hybrid Fiber

The influence of steel fiber and polypropylene fiber mixed on compressive strength of high performance concrete (HPC) was studied. The steel fiber content (0.5%, 1.0%, 1.5%, 2.0%) (volume fraction, the same below), polypropylene fiber content (0.05%, 0.1%, 0.15%, 0.2%) and length (5mm, 6.5mm, 12mm, 18mm) were studied by L16 (45) orthogonal test for 28d ages, the range analysis and variance analysis of the test results are carried out, and the prediction model of compressive strength of hybrid fiber reinforced concrete was established. The results show that: The significant influence factor of concrete compressive strength is the volume fraction of polypropylene fiber, while the length of polypropylene fiber and the volume fraction of steel fiber are not significant; the concrete compressive strength with polypropylene fiber shows negative hybrid effect; The prediction model of compressive strength of hybrid fiber reinforced concrete has high accuracy, and the average relative errors is 2.96%.

Flexural Toughness of Hybrid Fiber Reinforced High-Performance Concrete under Three-Point Bending

2013 ◽  
Vol 357-360 ◽  
pp. 1110-1114
Author(s):  
Dong Tao Xia ◽  
Xiang Kun Liu ◽  
Bo Ru Zhou
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Fiber Volume ◽  
Flexural Toughness

A set of new hybrid fiber reinforced high-performance concrete was developed and studied by experiment. The fibers incorporated the concrete are the collection of the steel fiber, modified polypropylene fiber and polypropylene with total fiber content not more than 1%. And the compressive test, splitting tensile test and the flexural toughness test were performed on eight groups of specimens. Based on the load-deflection and load-CMOD curves and the equivalent flexural tensile strength, the effect of fiber volume fraction and hybrid mode upon concrete's mechanical properties and post-peak behavior were investigated. The test results show that the mixing of the three different fibers can increase concrete's splitting tensile strength and flexural toughness more effectively with no significantly effect on compressive strength. The mixture of the three different fibers exist the optimization problem. Based on the results of the analysis, the compatible proportion of the three fibers is 0.7% steel fiber, 0.19% modified polypropylene fiber and 0.11% polypropylene fiber.

Design Method of Shear Resistance of Hybrid Fiber Reinforced High Performance Concrete Deep Beams

2013 ◽  
Vol 477-478 ◽  
pp. 686-689
Author(s):  
Sheng Bing Liu ◽  
Li Hua Xu ◽  
Hai Lin Lu ◽  
Hao Tan
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Design Method ◽  
Polypropylene Fiber ◽  
Shear Resistance ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Deep Beams ◽  
Splitting Failure

In order to study the shear resistance and design method of hybrid fiber (steel fiber and polypropylene fiber) reinforced high performance concrete deep beams, the shear tests were conducted according to the orthogonal experimental design. The contributory factors such as the characteristic parameters of steel fiber (types, volume fraction, aspect ratio), the volume fraction of polypropylene fiber, the ratio of web horizontal reinforcement and the ratio of web vertical reinforcement were analyzed. Results illuminate that shear failure mode of hybrid fiber reinforced HPC deep beams are splitting failure and diagonal compression failure. Hybrid fiber can notably increase the diagonal cracking strength and shear strength of HPC deep beams. The diagonal cracking strength is increased by 5.6%~83.8% while the shear strength is increased by15.6%~35.2%. A formula to calculate the shear resistance of hybrid fiber reinforced HPC deep beams is put forward based on spatial strut-and-tie mode and splitting failure. Meantime test verification is carried out and the calculated results are satisfied.

Parametric study of multi-story, perforated, partially grouted masonry walls subjected to in-plane cyclic actions

2020 ◽  
Author(s):  
Klaus Medeiros ◽  
Kyle Chavez ◽  
Fernando S. Fonseca ◽  
Guilherme Parsekian ◽  
Nigel G. Shrive
Keyword(s):  
Experimental Data ◽  
Shear Strength ◽  
Aspect Ratio ◽  
Load Capacity ◽  
Axial Stress ◽  
Reinforcement Ratio ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Initial Stiffness ◽  
Vertical Reinforcement

Finite element models were developed to assess the influence of several parameters on the load capacity, deflection, and initial stiffness of multi-story, partially grouted masonry walls with openings. The base model was validated with experimental data from three walls. The analyses indicated that the load capacity of masonry walls was considerably sensitive to the ungrouted and grouted masonry strengths and mortar shear strength; moderately sensitive to the vertical reinforcement ratio and aspect ratio; slightly sensitive to the axial stress; and almost insensitive to the opening size, reinforcement spacing, and horizontal reinforcement ratio. The deflection of the walls had well-defined correlations with the masonry strength, vertical reinforcement, axial stress and aspect ratio. The initial stiffness was especially sensitive to the axial stress and the aspect ratio, but weakly correlated with the opening size, and the spacing and size of the reinforcement.

scholarly journals Behavior of high performance artificial lightweight aggregate concrete reinforced with hybrid fibers

2018 ◽  
Vol 162 ◽  
pp. 02001
Author(s):  
Wasan Khalil ◽  
Hisham Ahmed ◽  
Zainab Hussein
Keyword(s):  
Tensile Strength ◽  
Aspect Ratio ◽  
Steel Fiber ◽  
Fiber Type ◽  
Lightweight Aggregate ◽  
Plain Concrete ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber

In this investigation, sustainable High Performance Lightweight Aggregate Concrete (HPLWAC) containing artificial aggregate as coarse lightweight aggregate (LWA) and reinforced with mono fiber, double and triple hybrid fibers in different types and aspect ratios were produced. High performance artificial lightweight aggregate concrete mix with compressive strength of 47 MPa, oven dry density of 1828 kg/m3 at 28 days was prepared. The Fibers used included, macro hooked steel fiber with aspect ratio of 60 (type S1), macro crimped plastic fiber (P) with aspect ratio of 63, micro steel fiber with aspect ratio of 65 (type S), and micro polypropylene fiber (PP) with aspect ratio of 667. Four HPLWAC mixes were prepared including, one plain concrete mix (without fiber), one mono fiber reinforced concrete mixes (reinforced with plastic fiber with 0.75% volume fraction), one double hybrid fiber reinforced concrete mixes (0.5% plastic fiber + 0.25% steel fiber type S), and a mix with triple hybrid fiber (0.25% steel fiber type S1+ 0.25% polypropylene fiber + 0.25% steel fiber type S). Fresh (workability and fresh density) and hardened concrete properties (oven dry density, compressive strength, ultrasonic pulse velocity, splitting tensile strength, flexural strength, static modules of elasticity, thermal conductively, and water absorption) were studied. Generally, mono and hybrid (double and triple) fiber reinforced HPLWAC specimens give a significant increase in splitting tensile strength and flexural strength compared with plain HPLWAC specimens. The percentage increases in splitting tensile strength for specimens with mono plastic fiber are, 20.8%, 31.9%, 36.4% and 41%, while the percentage increases in flexure strength are 19.5%, 37%, 33.9% and 34.2% at 7, 28, 60, 90 days age respectively relative to the plain concrete. The maximum splitting tensile and flexure strengths were recorded for triple hybrid fiber reinforced HPLWAC specimens. The percentage increases in splitting tensile strength for triple hybrid fiber reinforced specimens are 19.5%, 37%, 33.9% and 34.2%, while the percentage increases in flexure strength are 50.5%, 62.4. %, 66.8% and 62.2% at 7, 28, 60 and 90 days age respectively relative to the plain concrete specimens.

scholarly journals Behavior of Partially Grouted Concrete Masonry Walls under Quasi-Static Cyclic Lateral Loading

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2424
Author(s):  
Sebastián Calderón ◽  
Laura Vargas ◽  
Cristián Sandoval ◽  
Gerardo Araya-Letelier
Keyword(s):  
Shear Strength ◽  
Aspect Ratio ◽  
Load Capacity ◽  
Masonry Walls ◽  
Lateral Stiffness ◽  
Edge Elements ◽  
Vertical Reinforcement ◽  
Concrete Masonry ◽  
Resistance Degradation ◽  
Concrete Masonry Walls

Eight partially grouted (PG-RM) concrete masonry walls were tested to study the influence of the strength and width of blocks, the wall aspect ratio, the horizontal and vertical reinforcement ratio, and the presence of edge elements (flanges). The results were analyzed in terms of the failure mode, damage progression, shear strength, lateral stiffness degradation, equivalent viscous damping ratio, and displacement ductility. Additionally, the performances of some existing shear expressions were analyzed by comparing the measured and predicted lateral load capacity of the tested walls. Based on the results, a slight increment in the lateral stiffness was achieved when employing stronger blocks, while the shear strength remained constant. Besides, increasing the width of concrete blocks did not have a significant effect on the shear strength nor in the initial tangential stiffness, but it generated a softer post-peak strength degradation. Increasing the wall aspect ratio reduced the brittleness of the response and the shear strength. Reducing the amount of vertical reinforcement lowered the resulting shear strength, although it also slowed down the post-peak resistance degradation. Transversal edge elements provided integrity to the wall response, generated softer resistance degradation, and improved the symmetry of the response, but they did not raise the lateral resistance.

Abrasion of Reactive Powder Concrete under Direct Water Impact

2020 ◽  
Vol 897 ◽  
pp. 41-48 ◽  
Author(s):  
Munther L. Abdul Hussein ◽  
Sallal R. Abid ◽  
Sajjad H. Ali
Keyword(s):  
Steel Fiber ◽  
Fiber Type ◽  
Polypropylene Fiber ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Fiber Distribution ◽  
Hybrid Fiber ◽  
Normal Concrete ◽  
Weight Losses ◽  
Reactive Powder

An experimental program was directed in this study to evaluate the abrasion resistance of reactive powder concrete (RPC) under direct normal impact of water jet. Abrasion and compressive strength specimens were cast from six RPC mixtures using different single and hybrid distributions of 6 mm-length and 15 mm-length micros-steel fibers and 18 mm-length polypropylene fiber. Fixed mix proportions were used for the six RPC mixtures and with fixed total volumetric fiber content of 2.5%. In addition to the RPC mixtures, a normal concrete mixture was prepared for comparison purposes. All specimens were cured in the same conditions and tested at an age of 28 days. The test results showed that abrasion weight losses increase with time at rates that are independent of fiber type and fiber distribution. The results also showed that all RPC mixtures exhibited significantly lower abrasion losses than normal concrete. The lowest percentage abrasion weight losses were recorded for the mixture with pure 15 mm micro-steel, where after 12 testing hours, it was 0.41% of the total weight before testing. On the other hand, the mixture with pure 6 mm micro-steel fiber exhibited the highest percentage abrasion weight loss (0.98%) among the six RPC mixtures. Another conclusion is that the inclusion of polypropylene fiber to compose hybrid fiber distribution with micro-steel fiber led mostly to lower abrasion losses.

Shear Behavior of Reinforced Concrete Deep Beams with Various Horizontal to Vertical Reinforcements and Shear Span-to-Effective Depth Ratios

2014 ◽  
Vol 931-932 ◽  
pp. 473-477
Author(s):  
Prach Amornpinnyo ◽  
Jaruek Teerawong
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Beam Specimen ◽  
Test Results ◽  
Deep Beams ◽  
Shear Span ◽  
Strut And Tie ◽  
Vertical Reinforcement ◽  
Effective Depth ◽  
Strut And Tie Model

This paper presents the test results on the shear behavior of reinforced concrete deep beams with six steel reinforcement configurations. They were designed in accordance with the method given in the ACI 318-11. The specimens were subjected to the single concentrated loading at mid-span. The horizontal to vertical reinforcement ratios and shear span-to-effective depth ratios were the variables studied. The shear span-to-effective depth ratios of the beam specimen were between 1.5 to 2.0. The strut-and-tie model was used for the analysis. The test results indicated that the first diagonal cracking load and the failure mode were controlled by the horizontal to vertical reinforcement ratios and the shear span-to-depth ratios. The tests consistently gave the strength values slightly less than those calculated by using the ACI model. A modified ACI model for strut-and-tie was thus proposed and was found to accurately fit the experimental results.

Study on Performance about Hybrid Fiber Concrete of Airport Pavement

2014 ◽  
Vol 1065-1069 ◽  
pp. 706-709 ◽  
Author(s):  
Xiao Jun Liu ◽  
Che Fei Zhu ◽  
Yong Gen Wu ◽  
Qing Tao Liu
Keyword(s):  
Mechanical Properties ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Orthogonal Experiment ◽  
Basalt Fiber ◽  
Fiber Reinforced Concrete ◽  
Hybrid Fiber ◽  
Airport Pavement ◽  
Fiber Concrete ◽  
Pavement Concrete

In order to meet the requirements of the use of aircraft, improve mechanical properties of pavement concrete, the steel fiber mixed basalt hybrid fiber reinforced concrete technical route was proposed, by using the method of orthogonal experiment, steel fiber with 1.2%,1.5%,1.8% these 3 volume fraction and basalt fiber in 0.05%,0.1%,0.15% these 3 volume fraction mixed, research the rules of its effect on the performance of airport pavement concrete.

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