scholarly journals Material Analysis of Steel Fibre Reinforced High-Strength Concrete in Terms of Flexural Behaviour. Experimental and Numerical Investigation

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1631 ◽  
Author(s):  
Czesław Bywalski ◽  
Maciej Kaźmierowski ◽  
Mieczysław Kamiński ◽  
Michał Drzazga
Keyword(s):  
Tensile Strength ◽  
Fracture Energy ◽  
High Strength Concrete ◽  
Steel Fibre ◽  
High Strength ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Strength Concrete ◽  
Flexural Tensile Strength ◽  
Crack Tip Opening

The paper presents the results of tests for flexural tensile strength (fct,fl) and fracture energy (Gf) in a three-point bending test of prismatic beams with notches, which were made of steel fibre reinforced high-strength concrete (SFRHSC). The registration of the conventional force–displacement (F–δ) relationship and unconventional force-crack tip opening displacement (CTOD) relationship was made. On the basis of the obtained test results, estimations of parameters fct,fl and Gf in the function of fibre reinforcement ratio were carried out. The obtained results were applied to building and validating a numerical model with the use of the finite element method (FEM). A non-linear concrete damaged plasticity model CDP was used for the description of the concrete. The obtained FEM results were compared with the experimental ones that were based on the assumed criteria. The usefulness of the flexural tensile strength and fracture energy parameters for defining the linear form of weakening of the SFRHSC material under tension, was confirmed. Own equations for estimating the flexural tensile strength and fracture energy of SFRHSC, as well as for approximating deflections (δ) of SFRHSC beams as the function of crack tip opening displacement (CTOD) instead of crack mouth opening displacement (CMOD), were proposed.

Mechanical Properties of Steel Fibre-Reinforced High Strength Concrete with High early-Age Strength Used in Freezing Shaft Lining

2012 ◽  
Vol 174-177 ◽  
pp. 1388-1393
Author(s):  
Hai Qing Song ◽  
Teng Long Zheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
High Strength Concrete ◽  
Steel Fibre ◽  
High Strength ◽  
Plain Concrete ◽  
Split Tensile Strength ◽  
Strength Concrete

Plain concrete is susceptible to cracking under aggressive environment such as in freezing shaft. And addition of steel fibres in plain high strength concrete is proved to be effective in cracking resistance and brittleness improvement, etc. This paper presents results of experimental investigation carried out to study the mechanical properties of steel fibre-reinforced concrete having volume fractions of 0.38%, 0.51% and 0.64% for two types of fibres respectively. The results of this study revealed that there is an increase for all the mechanical properties such as compressive strength, split tensile strength, modulus of elasticity and flexural strength. Enhancement for split tensile strength and flexural strength is more evident than compressive strength.

scholarly journals Effect of Ambient and Elevated Temperature on the Residual Splitting and Flexural Tensile Strength of Normal and High Strength Concrete

2019 ◽  
Vol 9 (1) ◽  
pp. 6321-6326
Keyword(s):  
Tensile Strength ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
High Strength ◽  
Significant Loss ◽  
Thermal Loads ◽  
Strength Concrete ◽  
Hold Period ◽  
Heating And Cooling ◽  
Flexural Tensile Strength

Experimental test have carried out to investigate the behavior of residual tensile strength of concrete prepared using normal and high strength concrete. For the same purpose, cylindrical and prism-shaped specimens of concrete were caste and consecutively subjected to heating and cooling condition in the laboratory-controlled environment. A hold period of three hours was provided to impart the heating-cooling phenomenon inside the electrical furnace at four different sets of temperatures. The elevated temperatures chosen for the present tensile behavior study are 200oC, 400oC, 600oC, and 800oC. Strength was also determined at the ambient environment for the purpose of comparing the effects of thermal loads on the behavior of strength. A significant loss in tensile strength has been observed in concrete mixes at various temperatures. The outcomes of the current experimental work are termed useful for understanding key mechanical characteristics of concrete under the effect of thermal loads.

scholarly journals Application of fracture energy for the assessment of frost degradation of high-strength concretes

2021 ◽  
Vol 20 (2) ◽  
pp. 057-068
Author(s):  
Sylwia Borowska ◽  
Marta Kosior-Kazberuk
Keyword(s):  
Fracture Energy ◽  
High Strength ◽  
Bending Test ◽  
Structural Defects ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Critical Crack ◽  
Three Point Bending ◽  
Freeze Thaw ◽  
Crack Tip Opening

Knowledge of fracture mechanics parameters can help for a more accurate assessment of frost degradation of high-strength concrete. High strength concretes, despite the tight structure, are characterized by increased brittleness. Cracks in the concrete structure are places of accumulation of significant stresses. Additional stresses resulting from cyclic freeze/thaw stimulate the material destruction processes. The basic strength parameters of concrete do not take into account structural defects of the material and do not give a complete description of susceptibility to damage caused by, e.g., frost degradation. This study aimed to determine the relationship between frost degradation of high-strength concretes and changes in the value of their fracture energy associated with the initiation of cracking after 150, 250, 350 and 450 freeze/thaw cycles. The research was carried out using 100 × 100 × 400 mm samples, with a pre-initiated 30 mm deep notch. The I load model under a three-point bending test was used, based on the procedure recommended by RILEM. Concrete with a compressive strength of 90 MPa with steel fibres and a mixture of steel and basalt fibers was tested. The obtained results allow for the evaluation of frost degradation using fracture energy GF and critical crack tip opening displacement CTODc.

Mechanical Properties of Reactive Power Concrete and Ultra-High Strength Concrete with Coarse Aggregate

2014 ◽  
Vol 629-630 ◽  
pp. 112-118
Author(s):  
Juan Yang ◽  
Gai Fei Peng
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fracture Energy ◽  
High Strength Concrete ◽  
Reactive Power ◽  
Coarse Aggregate ◽  
High Strength ◽  
Splitting Tensile Strength ◽  
Strength Concrete ◽  
Maximum Value

An experimental investigation on the variation of compressive strength, splitting tensile strength and fracture energy, with the ratios of water to binder (W/B) of ultra-high strength concretes, including the reactive power concrete (RPC) and ultra-high strength concrete with coarse aggregate (UHSC), has been carried out. The W/B varied between 0.14 and 0.22 at a constant increment of 0.02. It was observed that, compressive strength of RPC almost remained the unchanged, when the W/B was between 0.14 and 0.18. However, it decreased dramatically when the ratios were 0.20 and 0.22. For UHSC, the compressive strength was the highest value at the ratio of 0.18. The results of the two concretes could not comply with the Abrams' generalized W/B ratio law. Moreover, splitting tensile strength of RPC and UHSC decreased continually as the ratio increased from 0.14 to 0.22. Fracture energy of RPC was more or less the same when the ratios were between 0.16 and 0.20, and the maximum value was at 0.14. Fracture energy was observed to be almost no variation for UHSC at all ratios

Effect of fracture path on the fracture energy of high-strength concrete

2001 ◽  
Vol 31 (11) ◽  
pp. 1601-1606 ◽  
Author(s):  
An Yan ◽  
Ke-Ru Wu ◽  
Dong Zhang ◽  
Wu Yao
Keyword(s):  
Fracture Energy ◽  
High Strength Concrete ◽  
High Strength ◽  
Fracture Path ◽  
Strength Concrete

Experimental Study on Fracture Toughness of Q460C the High-Strength Construction Steel at Low Temperature

2011 ◽  
Vol 71-78 ◽  
pp. 890-897 ◽  
Author(s):  
Yuan Qing Wang ◽  
Yun Lin ◽  
Yan Nian Zhang ◽  
Yong Jiu Shi
Keyword(s):  
Low Temperature ◽  
High Strength ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Three Point Bending ◽  
Function Fitting ◽  
Ductile Brittle Transition Temperature ◽  
Boltzmann Function ◽  
Fracture Appearance ◽  
Crack Tip Opening

Three point bending tests were carried out on 14mm-thick Q460C the high-strength structural steel at low temperature, and scanning electronic microscope of the fracture appearance was analyzed. The results showed that the obvious feature of brittle mechanism was shown on the three point bending specimen fracture whose testing took place at -40°C. And the crack tip opening displacement value of Q460C steel, which was less than that of Q235 steel, Q345 steel and Q390 steel at low temperature, tended to decrease with respect to the temperature reduction. Moreover, a Boltzmann function fitting analysis was applied to the experimental data, and the ductile-brittle transition temperature and the changing regularity were obtained.

Influence of Nano Particles in the Flexural Behavior of High-Strength Reinforced Concrete Beams

2021 ◽  
Vol 1160 ◽  
pp. 25-43
Author(s):  
Naglaa Glal-Eldin Fahmy ◽  
Rasha El-Mashery ◽  
Rabiee Ali Sadeek ◽  
L.M. Abd El-Hafaz
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Nano Particles ◽  
Flexural Behavior ◽  
Single Type ◽  
Strength Concrete ◽  
Flexural Ductility

High strength concrete (HSC) characterized by high compressive strength but lower ductility compared to normal strength concrete. This low ductility limits the benefit of using HSC in building safe structures. Nanomaterials have gained increased attention because of their improvement of mechanical properties of concrete. In this paper we present an experimental study of the flexural behavior of reinforced beams composed of high-strength concrete and nanomaterials. Eight simply supported rectangular beams were fabricated with identical geometries and reinforcements, and then tested under two third-point loads. The study investigated the concrete compressive strength (50 and 75 N/mm2) as a function of the type of nanomaterial (nanosilica, nanotitanium and nanosilica/nanotitanium hybrid) and the nanomaterial concentration (0%, 0.5% and 1.0%). The experimental results showed that nano particles can be very effective in improving compressive and tensile strength of HSC, nanotitanium is more effective than nanosilica in compressive strength. Also, binary usage of hybrid mixture (nanosilica + nanotitanium) had a remarkable improvement appearing in compressive and tensile strength than using the same percentage of single type of nanomaterials used separately. The reduction in flexural ductility due to the use of higher strength concrete can be compensated by adding nanomaterials. The percentage of concentration, concrete grade and the type of nanomaterials, could predominantly affect the flexural behavior of HSRC beams.

Breakout Capacity of Headed Anchors in Steel Fibre Normal and High Strength Concrete

2012 ◽  
Vol 5 (7) ◽  
pp. 485-496 ◽  
Author(s):  
Saad Ali AlTaan ◽  
AbdulKader Ali Mohammed ◽  
Alaa AbdulRahman Al-Jaffal
Keyword(s):  
High Strength Concrete ◽  
Steel Fibre ◽  
High Strength ◽  
Strength Concrete
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