scholarly journals Properties of Lightweight Aggregate Concrete Reinforced with Carbon and/or Polypropylene Fibers

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 640 ◽  
Author(s):  
Hui Wei ◽  
Tao Wu ◽  
Xue Yang
Keyword(s):  
Tensile Strength ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Polypropylene Fibers ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Stress Strain ◽  
Aggregate Concrete ◽  
Ductility Index ◽  
Hybrid Forms

The impact of carbon and polypropylene fibers in both single and hybrid forms on the properties of lightweight aggregate concrete (LWAC), including the slump, density, segregation resistance, compressive strength, splitting tensile strength, flexural strength, and compressive stress–strain behavior, were experimentally investigated. The toughness ratio and ductility index were introduced for quantitatively evaluating the energy-absorbing capacity and post-peak ductility. A positive synergistic effect of hybrid carbon and polypropylene fibers was obtained in terms of higher tensile strength, toughness, and ductility. The toughness ratio and ductility index of hybrid fiber-reinforced LWAC were increased by 26%–37% and 12%–27% compared with plain LWAC, respectively. The fiber in both single and hybrid forms had a smaller effect on the linearity ascending branch of the stress–strain curves, whereas the post-peak patterns in terms of the toughness and ductility for the hybrid fiber-reinforced LWAC were significantly improved when the fiber in hybrid form.

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.

Experimental Study on Mechanical Properties of Hybrid Fiber Reinforced Full Lightweight Aggregate Concrete

2011 ◽  
Vol 197-198 ◽  
pp. 911-914 ◽  
Author(s):  
Li Yun Pan ◽  
Hao Yuan ◽  
Shun Bo Zhao
Keyword(s):  
Mechanical Properties ◽  
Apparent Density ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Mass Content ◽  
Hybrid Fiber ◽  
Aggregate Concrete

Tests were carried out to study mechanical properties of hybrid fiber reinforced full lightweight aggregate concrete (HFRFLAC), the hybrid fiber was composed by steel fiber and polypropylene fiber, the expanded-shale and lightweight sand were used as coarse and fine aggregates. The apparent density and strengths in cubic compressive, splitting tensile and flexural tensile states of HFRFLAC were obtained. The results show that the average dry apparent density increases with the increasing cement content, which is much more affected by fraction of steel fiber by volume than mass content of polypropylene fiber; the tensile strengths increase somewhat with the increasing mass content of polypropylene fiber; all of the strengths increase with the increasing fraction of steel fiber by volume, and obvious are the enhancement of tensile strengths; there are somewhat relevance between the effects of polypropylene fiber and steel fiber on mechanical properties of HFRFLAC.

Study on Hybrid Fiber Reinforced Lightweight Aggregate Concrete

2013 ◽  
Vol 477-478 ◽  
pp. 949-952
Author(s):  
Yan Chen
Keyword(s):  
Tensile Strength ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Hybrid Fiber ◽  
Aggregate Concrete ◽  
Concrete Mix ◽  
Fiber Materials ◽  
Pva Fiber ◽  
Better Than

For lightweight aggregate concrete, fiber materials can reinforce its toughness and strength better and improve its segregation degree greatly. Specifically, as the experiment indicates, the fluidity of concrete mix decreases slightly after 0.5% basalt fiber and 0.5% PVA fiber are incorporated into the concrete with FA ceramsite as lightweight aggregate. However, its segregation degree reduces about 50%. And its 28d cubic compressive strength increases 0.7% and 28d splitting tensile strength increases 12.7%. Therefore, this effect is better than that of adding only one kind of fiber.

scholarly journals Failure Criteria and Constitutive Relationship of Lightweight Aggregate Concrete under Triaxial Compression

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 507
Author(s):  
Peihuan Ye ◽  
Yuliang Chen ◽  
Zongping Chen ◽  
Jinjun Xu ◽  
Huiqin Wu
Keyword(s):  
Triaxial Compression ◽  
Lightweight Aggregate ◽  
Confining Pressure ◽  
Failure Criteria ◽  
Constitutive Relationship ◽  
Lightweight Aggregate Concrete ◽  
Stress Strain ◽  
Aggregate Concrete ◽  
Stress Theory ◽  
Relationship Of

This paper investigates the compression behavior and failure criteria of lightweight aggregate concrete (LAC) under triaxial loading. A total of 156 specimens were tested for three parameters: concrete strength, lateral confining pressure and aggregate immersion time, and their effects on the failure mode of LAC and the triaxial stress-strain relationship of LAC is studied. The research indicated that, as the lateral constraint of the specimen increases, the failure patterns change from vertical splitting failure to oblique shearing failure and then to indistinct traces of damage. The stress-strain curve of LAC specimens has an obvious stress plateau, and the curve no longer appears downward when the confining pressure exceeds 12 MPa. According to the experimental phenomenon and test data, the failure criterion was examined on the Mohr–Coulomb theory, octahedral shear stress theory and Rendulic plane stress theory, which well reflects the behavior of LAC under triaxial compression. For the convenience of analysis and application, the stress-strain constitutive models of LAC under triaxial compression are recommended, and these models correlate well with the test results.

scholarly journals An Experimental Investigation of Dynamic Properties of Fiber-Reinforced Tire-Derived Lightweight-Aggregate Concrete

2020 ◽  
Vol 5 (6) ◽  
pp. 702-707
Author(s):  
Fariborz M. Tehrani ◽  
Nazmieh A. Masswadi ◽  
Nathan M. Miller ◽  
Arezoo Sadrinezhad
Keyword(s):  
Energy Absorption ◽  
Dynamic Properties ◽  
Fiber Reinforcement ◽  
Lightweight Aggregate ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Aggregate Concrete

This paper presents the results of an experimental study to investigate dynamic properties of polypropylene fiber-reinforced concrete beams with lightweight expanded shale (ES) and tire-derived aggregates (TDA). The mixture design followed past experiences in combining ES and TDA to enhance toughness and energy absorption in flexural behavior. The new mixture also contained 2% fiber by volume to improve such properties further. Experiments included compressive testing on cylindrical specimens as well as flexural testing on rectangular specimens to verify mechanical properties of fiber-reinforced tire-derived lightweight aggregate concrete (FRTDLWAC) subject to static loading. The results of these experiments confirmed reduction of mechanical strength due to addition of TDA and improvements in flexural strength due to fiber reinforcement. The dynamic testing included non-destructive impact loads applied to flexural specimens using a standard Schmidt hammer. A high-speed camera recorded the response of the system at 200 frames per second to allow detailed observations and measurements. Interpretation of energy-based dynamic results revealed that TDA enhances energy absorption through damping in flexural behavior. Results also indicated that fiber reinforcement reduces the amount of absorbed dynamic energy, even though; it enhances the absorbed strain energy due to crack bridging effect.

scholarly journals Flexural Capacity and Deflection of Fiber-Reinforced Lightweight Aggregate Concrete Beams Reinforced with GFRP Bars

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 873 ◽  
Author(s):  
Xi Liu ◽  
Yijia Sun ◽  
Tao Wu
Keyword(s):  
Lightweight Aggregate ◽  
Reinforcement Ratio ◽  
Steel Fibers ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Flexural Capacity ◽  
Short Term ◽  
Aggregate Concrete ◽  
Reinforced Polymer ◽  
Stiffness Model

Adding fibers is highly effective to enhance the deflection and ductility of fiber-reinforced polymer (FRP)-reinforced beams. In this study, the stress and strain conditions of FRP-reinforced lightweight aggregate concrete (LWC) beams with and without fibers at ultimate load level were specified. Based on the sectional analyses, alternative equations to predict the balanced reinforcement ratio and flexural capacity for beams failed by balanced failure and concrete crushing were established. A rational equation for estimating the short-term stiffness of FRP–LWC beams at service-load levels was suggested based on Zhu’s model. In addition, the contribution of the steel fibers on the short-term stiffness was quantified incorporating the effects of FRP reinforcement ratio. The proposed short-term stiffness model was validated with measured deflections from an experimental database for fiber-reinforced normal weight concrete (FNWC) beams reinforced with FRP bars. Furthermore, six glass fiber-reinforced polymer (GFRP)-reinforced LWC beams with and without steel fibers were tested under four-point bending. Based on the test results, the proposed models and procedures according to current design codes ACI 440.1R, ISIS-M03, GB 50608, and CSA S806 were linked together by comparing their predictions. The results showed that increasing the reinforcement ratio and adding steel fibers decreased the strain of the FRP bars. The flexural capacity of the LWC beams with and without steel fibers was generally underestimated by the design codes, while the proposed model provided accurate ultimate moment predictions. Moreover, the proposed short-term stiffness model yielded reasonable estimations of deflection for both steel fiber-reinforced lightweight aggregate concrete (SFLWC) and FNWC beams.

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