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Showing papers on "Flexural strength published in 2016"


Journal ArticleDOI
TL;DR: In this article, an Acrylonitrile butadiene styrene (ABS) nanocomposites with organic modified montmorillonite (OMMT) were prepared by melt intercalation and evaluated by tensile, flexural, thermal expansion and dynamic mechanical tests.

444 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of three shaped steel fibers (straight, corrugated, and hooked-end) with different fiber contents by volume on mechanical properties of ultra high performance concrete (UHPC) were investigated.

443 citations


Journal ArticleDOI
TL;DR: In this paper, a continuous carbon fiber reinforced polylactic acid composite was manufactured by the rapid prototyping approach of three-dimensional (3D) printing, and the comparison experiments of printed samples with or without preprocessed carbon fiber bundle were performed.

439 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of processing technique on the mechanical behaviour of virgin ABS was investigated in terms of varying raster angle and gap to further explore the potential of this technique.

407 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a comprehensive review of the mechanism of crack formation and propagation, compressive strength, modulus of elasticity, stress-strain behavior, tensile strength (TS), flexural strength, drying shrinkage, creep, electrical resistance, and chloride migration resistance of high performance fiber reinforced concrete.
Abstract: In recent years, an emerging technology termed, “High-Performance Fiber-Reinforced Concrete (HPFRC)” has become popular in the construction industry. The materials used in HPFRC depend on the desired characteristics and the availability of suitable local economic alternative materials. Concrete is a common building material, generally weak in tension, often ridden with cracks due to plastic and drying shrinkage. The introduction of short discrete fibers into the concrete can be used to counteract and prevent the propagation of cracks. Despite an increase in interest to use HPFRC in concrete structures, some doubts still remain regarding the effect of fibers on the properties of concrete. This paper presents the most comprehensive review to date on the mechanical, physical, and durability-related features of concrete. Specifically, this literature review aims to provide a comprehensive review of the mechanism of crack formation and propagation, compressive strength, modulus of elasticity, stress–strain behavior, tensile strength (TS), flexural strength, drying shrinkage, creep, electrical resistance, and chloride migration resistance of HPFRC. In general, the addition of fibers in high-performance concrete has been proven to improve the mechanical properties of concrete, particularly the TS, flexural strength, and ductility performance. Furthermore, incorporation of fibers in concrete results in reductions in the shrinkage and creep deformations of concrete. However, it has been shown that fibers may also have negative effects on some properties of concrete, such as the workability, which get reduced with the addition of steel fibers. The addition of fibers, particularly steel fibers, due to their conductivity leads to a significant reduction in the electrical resistivity of the concrete, and it also results in some reduction in the chloride penetration resistance of the concrete.

350 citations


Journal ArticleDOI
TL;DR: In this article, a carbon fiber/graphene oxide-epoxy hybrid composites were used to improve the mechanical properties of polymer composites, and graphene oxide was used as one of the filler for the development of carbon fiber composite.

330 citations


Journal ArticleDOI
TL;DR: In this article, the results of an experimental investigation to comparatively study the depth of chloride penetration, resistance to acid attack and macrocell corrosion of rubberized concrete and control mix concrete were presented.

300 citations


Journal ArticleDOI
TL;DR: In this paper, the formation of disordered solid solution in the hexagonal close-packed (hcp) structure in the GdHoLaTbY alloy and its mechanical properties were investigated.

297 citations


Journal ArticleDOI
TL;DR: The VS zirconia reinforced lithium silicate glass-ceramic revealed higher mechanical properties compared with IC lithium disilicate glass -ceramic and revealed a lower probability of failure and a higher strength according to Weibull analysis.

293 citations


Journal ArticleDOI
TL;DR: A novel hexagonal architecture for a glass-ceramic scaffold is designed to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa, which is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater for ceramic and glass scaffolds at similar porosity.
Abstract: A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100–150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1–10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

270 citations


Journal ArticleDOI
TL;DR: In this paper, the authors evaluated the relative merits of two types of basalt fiber (bundle dispersion fibres and minibars) in enhancing the mechanical behaviour of concrete.

Journal ArticleDOI
TL;DR: In this article, a robust hydrogel formulation was optimized for use as the extrusion paste for robocasting and the printing process was optimised with the aim of attaining dense monolithic ceramic parts.
Abstract: Robocasting is a 3D printing technique that may be able to achieve the much-coveted goal of reliable, complex ceramic parts with low porosity and high strength. In this work a robust hydrogel formulation was optimised for use as the extrusion paste for robocasting. The paste’s rheological properties were characterised and the printing process was optimised with the aim of attaining dense monolithic ceramic parts. The pastes exhibit a characteristic shear thinning behaviour with yield stresses that can reach values above 1 kPa and depend mostly on their solid content and the particle size distribution. It is possible to formulate printable Al2O3 and SiC inks with solid contents as high as 40 vol% that reached densities up to 95th% for SiC and 97th% for Al2O3 with flexural strengths of 300 MPa and 230 MPa respectively after sintering. The sources of strength limiting defects are identified and related to the printing process.

Journal ArticleDOI
TL;DR: In this article, the effects of graphite nanoplatelets (GNPs) and carbon nanofibers (CNFs) on mechanical properties of ultra-high-performance concrete (UHPC) are investigated.
Abstract: Effects of graphite nanoplatelets (GNPs) and carbon nanofibers (CNFs) on mechanical properties of ultra-high-performance concrete (UHPC) are investigated. A non-proprietary UHPC mixture composed of 0.5% steel micro fibers, 5% silica fume, and 40% fly ash was used. The content of the nanomaterials ranged from 0 to 0.3% by weight of cementitious materials. The nanomaterials were dispersed using optimized surfactant content and ultra-sonification to ensure uniform dispersion in the UHPC mixture. As the content of nanomaterials is increased from 0 to 0.3%, the tensile strength and energy absorption capacity can be increased by 56% and 187%, respectively; the flexural strength and toughness can be increased by 59% and 276%, respectively. At 0.2% of GNPs, the UHPCs exhibited “strain-hardening” in tension and in flexure.

Journal ArticleDOI
TL;DR: In this article, three types of hybrid green composites: kenaf-bamboo-coir/PLA, bamboo-and coir fibers were investigated by tensile and flexural tests.

Journal ArticleDOI
TL;DR: In this paper, the effect of coir fibres for use as reinforcement materials for polymer and cementitious composites was investigated, and the results showed that the treatment improved the tensile and flexural properties of composites.

Journal ArticleDOI
TL;DR: In this article, a simple and effective double-side pullout testing method was adopted to characterize the interfacial bond properties, which include pullout load-slip relationship, bond strength, and pullout energy, of steel fiber-matrix in ultra-high strength cement-based material (UHSC) with 0-25% silica fume by the mass of binder.
Abstract: The use of silica fume can significantly enhance mechanical properties of concrete given its beneficial filling and pozzolanic effects. In this study, a simple and effective double-side pullout testing method was adopted to characterize the interfacial bond properties, which include pullout load-slip relationship, bond strength, and pullout energy, of steel fiber-matrix in ultra-high strength cement-based material (UHSC) with 0–25% silica fume by the mass of binder. The effects of silica fume content on flowability, heat of hydration, compressive and flexural strengths, hydration products, and pore structure of matrix at different curing time were evaluated as well. Backscatter scanning electron microscopy (BSEM) and micro-hardness measurement were used to examine the quality of interfacial transition zone (ITZ) around the fiber. In terms of the results, the optimal silica fume content could be in the range of 15%–25%. UHSC mixtures with these dosages of silica fume showed significant improvement in pullout behavior. Its bond strength and pullout energy at 28 d could increase by 170% and 250% compared to the reference samples without any silica fume. The microstructural observation verified the findings on the macro-properties development. Formation of more and higher strength of hydration products and refinement of ITZ around the fiber ensured higher micro-hardness, and thus improved the bond to fiber.

Journal ArticleDOI
TL;DR: Resin composite and resin infiltrated ceramic materials have demonstrated adequate wear resistance for load bearing restorations, however, they will require at least similar material thickness as lithium disilicate restorATIONS due to their strength.

Journal ArticleDOI
TL;DR: In this paper, the effects of wettability, chemical characterization and nanometric roughness of two different fibers, polypropylene (PPF) and micro steel fibers (MSF), superposed by shrinkage of fly ash based geopolymer binder on fiber-matrix interaction and the consequent mechanical properties of the corresponding composites.

Journal ArticleDOI
TL;DR: In this article, the AA6351-AlN composites were characterized using scanning electron microscope (SEM) and x-ray diffraction (XRD) and the mechanical properties such as micro-hardness, compression strength, flexural strength and tensile strength of the proposed composite have been studied.
Abstract: In the present investigation, AA6351 aluminum alloy matrix composites reinforced with various percentages of AlN particles were fabricated by stir casting technique. The percentage of AlN was varied from 0 to 20% in a step of 4%. The prepared AA6351-AlN composites were characterized using scanning electron microscope (SEM) and x-ray diffraction (XRD). The mechanical properties such as micro-hardness, compression strength, flexural strength, and tensile strength of the proposed composite have been studied. X-ray diffraction patterns confirm the presence of AlN particles in the composites. SEM analysis reveals the homogeneous distribution of AlN particles in the AA6351 matrix. The mechanical properties of the composite were found to be noticeably higher than that of the plain matrix alloy due to augmented particle content. The produced composites exhibit superior mechanical properties when compared with unreinforced matrix alloy. Fracture surface analysis of tensile specimens show the ductile–brittle nature of failure in the composites.

Journal ArticleDOI
TL;DR: In this paper, the effect of colloidal nanosilica on the properties of High Performance Concrete with copper slag as fine aggregate at a constant replacement level of 40% was investigated.

Journal ArticleDOI
TL;DR: In this paper, fly ash based geopolymer concretes with different percentages of silica fume were made by using NaOH/sodium silicate and cured in an oven at 100°C.

Journal ArticleDOI
TL;DR: In this article, the suitability of scrap tire rubber as a partial substitute for natural fine aggregate in high strength cement concrete was analyzed using Scanning Electron Microscopy (SEM).

Journal ArticleDOI
01 Feb 2016
TL;DR: In this paper, the authors evaluated the tensile and flexural properties of ABS + hydrous magnesium silicate composite material for desktop 3D printing and found that low printing speed and low layer thickness has resulted maximum tensile strength.
Abstract: Additive Manufacturing (AM) technologies have been emerged as a fabrication method to obtain engineering components within a short span of time. Desktop 3D printing, also referred as additive layer manufacturing technology is one of the powerful method of rapid prototyping (RP) technique that fabricates three dimensional engineering components. In this method, 3D digital CAD data is converted directly to a product. In the present investigation, ABS + hydrous magnesium silicate composite was considered as the starting material. Mechanical properties of ABS + hydrous magnesium silicate composite material were evaluated. ASTM D638 and ASTM D760 standards were followed for carrying out tensile and flexural tests, respectively. Samples with different layer thickness and printing speed were prepared. Based on the experimental results, it is suggested that low printing speed, and low layer thickness has resulted maximum tensile and flexural strength, as compared to all the other process parameters samples.

Journal ArticleDOI
TL;DR: In this paper, a new processing technique consisting of the gelcasting, sintering and vacuum infiltration methods was proposed to fabricate high performance ceramic/polymer composites for electronic packaging.

Journal ArticleDOI
TL;DR: In this paper, an overview of the developments made in the area of natural fibres reinforced composites, in terms of their physical and mechanical properties, and crashworthiness properties, is presented.

Journal ArticleDOI
TL;DR: In this paper, the effects of nano-CaCO 3 and nano-SiO 2 contents on flowability, heat of hydration, mechanical properties, phase change, and pore structure of ultra-high strength concrete (UHSC) were investigated.
Abstract: Nanomaterials have attracted much interest in cement-based materials during the past decade. In this study, the effects of different nano-CaCO 3 and nano-SiO 2 contents on flowability, heat of hydration, mechanical properties, phase change, and pore structure of ultra-high strength concrete (UHSC) were investigated. The dosages of nano-CaCO 3 were 0, 1.6%, 3.2%, 4.8%, and 6.4%, by the mass of cementitious materials, while the dosages of nano-SiO 2 were 0, 0.5%, 1.0%, 1.5%, and 2%. The results indicated that both nano-CaCO 3 and nano-SiO 2 decreased the flowability and increased the heat of hydration with the increase of their contents. The optimal dosages to enhance compressive and flexural strengths were 1.6%–4.8% for the nano-CaCO 3 and 0.5%–1.5% for the nano-SiO 2 . Although compressive and flexural strengths were comparable for the two nanomaterials after 28 d, their strength development tendencies with age were different. UHSC mixtures with nano-SiO 2 showed continuous and sharp increase in strength with age up to 7 d, while those with nano-CaCO 3 showed almost constant strength between 3 and 7 d, but sharp increase thereafter. Thermal gravimetry (TG) analysis demonstrated that the calcium hydroxide (CH) content in UHSC samples decreased significantly with the increase of nano-SiO 2 content, but remained almost constant for those with nano-CaCO 3 . Mercury intrusion porosimetry (MIP) results showed that both porosity and critical pore size decreased with the increase of hydration time as well as the increase of nanoparticles content to an optimal threshold, beyond which porosity decreased. The difference between them was that nano-CaCO 3 mainly reacted with C 3 A to form carboaluminates, while nano-SiO 2 reacted with Ca(OH) 2 to form C S H. Both nano-CaCO 3 and nano-SiO 2 demonstrated nucleation and filling effects and resulted in less porous and more homogeneous structure.

Journal ArticleDOI
TL;DR: In this paper, hybrid laminates produced using carbon (C) and flax (F) fiber epoxy prepregs were fabricated with two different stacking sequences based on the presence of flax fibre as outer layers and carbon as inner layers (FCF) or vice versa (CFC).
Abstract: Hybrid laminates produced using carbon (C) and flax (F) fibre epoxy prepregs were fabricated with two different stacking sequences based on the presence of flax fibre laminates as outer layers and carbon as inner layers (FCF) or vice versa (CFC). Pure flax and pure carbon fibre reinforced laminates were also fabricated as a reference. Experimental tests were performed, which included four-point bending, falling weight impact tests at energies ranging from 5 to 30 J with determination of the barely visible impact damage (BVID) and post-impact flexural tests. As a whole, CFC proved slightly superior to FCF as for flexural performance, although the presence of flax laminates on the outside guaranteed a higher impact damage tolerance, acting as hindrance to crack propagation in the laminate. Specimens impacted at 10 J were also subjected to tensile tests monitored by Digital Image Correlation (DIC) that allowed preliminary identification of peculiar failure modes of the hybrid laminates.

Journal ArticleDOI
TL;DR: In this article, tire rubber crumbs (TRC) was used as a partial sand replacement (5, 10% and 15%) material in the mix design of self-compacting concrete.

Journal ArticleDOI
TL;DR: In this article, the authors evaluated the mechanical properties of heat-cured low-calcium fly-ash geopolymer concrete and the behavior of geopolymers concrete beams using a flexural test with four-point bending, elastic theory, and a finite element model.

Journal ArticleDOI
TL;DR: In this article, the flexural behavior of reinforced concrete beams retrofitted with ultra-high performance fiber reinforced concrete (UHPFRC) is investigated and experimental results are compared with 3-D finite element analysis.