Studies on effect of steel fiber and coarse aggregate on fracture properties of self compacting concrete using wedge splitting test

2019 ◽  
Vol 11 (6) ◽  
pp. 751-767
Author(s):  
Raja Rajeshwari B. ◽  
Sivakumar M.V.N.
Keyword(s):  
Fracture Energy ◽  
Coarse Aggregate ◽  
Peak Load ◽  
Mouth Opening ◽  
Test Method ◽  
Crack Mouth Opening Displacement ◽  
Fine Aggregate ◽  
Content Type ◽  
Fracture Properties ◽  
Splitting Test

Purpose Fracture properties depend on the type of material, method of testing and type of specimen. The purpose of this paper is to evaluate fracture properties by adopting a stable test method, i.e., wedge split test. Design/methodology/approach Coarse aggregate of three different sizes (20 mm, 16 mm and 12.5 mm), three ratios of coarse aggregate, fine aggregate (CA:FA) (50:50, 45:55, 40:60), presence of steel fibers, and specimens without and with guide notch were chosen as parameters of the study. Findings Load-crack mouth opening displacement curves indicate that for both fibrous and non-fibrous mixes, higher volume of aggregate and higher size of coarse aggregate have high fracture energy. Originality/value For all volumes of coarse aggregate, it was noticed that specimens with 12.5 mm aggregate size achieved highest peak load and abrupt drop post-peak. The decrease in coarseness of internal structure of concrete (λ) resulted in the increase of fracture energy.

scholarly journals Fracture Properties and Softening Curves of Steel Fiber-Reinforced Slag-Based Geopolymer Mortar and Concrete

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1445 ◽  
Author(s):  
Yao Ding ◽  
Yu-Lei Bai
Keyword(s):  
Fracture Toughness ◽  
Fracture Energy ◽  
Inverse Analysis ◽  
Steel Fiber ◽  
Mouth Opening ◽  
Crack Mouth Opening Displacement ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Opening Displacement ◽  
Fracture Properties

Adding short steel fibers into slag-based geopolymer mortar and concrete is an effective method to enhance their mechanical properties. The fracture properties of steel fiber-reinforced slag-based geopolymer concrete/mortar (SGC/SGM) and unreinforced control samples were compared through three-point bending (TPB) tests. The influences of steel fiber volume contents (1.0%, 1.5% and 2.0%) on the fracture properties of SGC and SGM were studied. Load-midspan deflection (P-δ) curves and load-crack mouth opening displacement (P-CMOD) curves of the tested beams were recorded. The compressive and splitting tensile strengths were also tested. The fracture energy, flexural strength parameters, and fracture toughness of steel fiber-reinforced SGC and SGM were calculated and analyzed. The softening curves of steel fiber-reinforced SGC and SGM were determined using inverse analysis. The experimental results show that the splitting tensile strength, fracture energy, and fracture toughness are significantly enhanced with fiber incorporation. A strong correlation between the equivalent and residual flexural strengths is also observed. In addition, the trilinear strain-softening curves obtained by inverse analysis predict well of the load-displacement curves recorded from TPB tests.

Fracture properties of GGBS-dolomite geopolymer concrete

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Saranya P. ◽  
Praveen Nagarajan ◽  
A.P. Shashikala
Keyword(s):  
Fracture Energy ◽  
Design Methodology ◽  
Characteristic Length ◽  
Peak Load ◽  
Critical Stress Intensity Factor ◽  
Bending Test ◽  
Geopolymer Concrete ◽  
Content Type ◽  
Fracture Properties ◽  
Three Point Bending

Purpose This study aims to predict the fracture properties of geopolymer concrete, which is necessary for studying failure behaviour of concrete. Design/methodology/approach Geopolymers are new alternative binders for cement in which polymerization gives strength to concrete rather than through hydration. Geopolymer concrete was developed from industrial byproducts such as GGBS and dolomite. Present study estimates the fracture energy of GGBS geopolymer concrete using three point bending test (RILEM TC50-FMC) with different percentages of dolomite and compare with cement concrete having same strength. Findings The fracture properties such as peak load, critical stress intensity factor, fracture energy and characteristic length are found to be higher for GGBS-dolomite geopolymer concrete, when their proportion becomes 70:30. Originality/value To the best of the authors’ knowledge, this is an original experimental work.

Experimental Study of the Influence of the Initial Notch Length in Cubical Concrete Wedge-Splitting Test Specimens

2012 ◽  
Vol 525-526 ◽  
pp. 209-212 ◽  
Author(s):  
Sara Korte ◽  
Veerle Boel ◽  
Wouter de Corte ◽  
Geert de Schutter ◽  
Stanislav Seitl
Keyword(s):  
Mouth Opening ◽  
Heterogeneous Material ◽  
Crack Mouth Opening Displacement ◽  
Opening Displacement ◽  
Test Configuration ◽  
Fracture Properties ◽  
Wedge Splitting Test ◽  
Splitting Test ◽  
Notch Length ◽  
Wedge Splitting

The wedge-splitting test (WST) is a frequently used test configuration for performing stable crack fracture experiments on concrete specimens, thus allowing to determine the fracture process and crack propagation in the heterogeneous material. However, there are no standard rules regarding the wedge-splitting specimens geometry, groove dimensions or notch length. This paper concentrates on the influence of the initial notch length in geometrically identical, cubical specimens, cast from vibrated concrete. The experimental results of nine WSTs under monotonic loading, including Fsp-CMOD curves - splitting force versus crack mouth opening displacement - and fracture energy Gf, are presented. An important effect of the starting notch length on the fracture properties is observed.

scholarly journals Influence of superabsorbent polymer on the splitting tensile strength and fracture energy of high-performance concrete

2018 ◽  
Vol 199 ◽  
pp. 11004 ◽  
Author(s):  
Babatunde James Olawuyi ◽  
William Peter Boshoff
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Fracture Energy ◽  
High Performance ◽  
High Performance Concrete ◽  
Water Immersion ◽  
Mouth Opening ◽  
Splitting Tensile Strength ◽  
Crack Mouth Opening Displacement ◽  
Splitting Test

Superabsorbent polymers (SAP) addition as an internal curing (IC) agent in concrete is an approach being adopted for the mitigation of autogenous shrinkage. Micro-voids created by SAP are arguably believed to be detrimental to the mechanical properties especially the fracture tendencies of the concrete. This paper presents the report of an experimental study of SAP’s influence on the splitting tensile strength and fracture energy of low water/binder (W/B) high-performance concrete (HPC). Reference HPC mixtures (M1F, M1S, M2 and M3) designed for a 28-day minimum cube compressive strength of 70 N/mm2 (MPa) were examined for the effect of SAP grain size, content and binder type on the above stated properties. Wedge splitting test was carried out on 100 mm cube specimen of HPC containing varied SAP contents (0.2, 0.3 and 0.4 by weight of binder (bwob)) and SAP sizes, cured by water immersion for 28, 56 and 90 days respectively. The results obtained was plotted as splitting force (Fsp in kN) against the crack mouth opening displacement (CMOD in mm) for computing the work of fracture (Wf), which is the area under the Fsp CMOD curve. The study concludes that the splitting tensile strength and fracture energy of the HPCs are not directly affected by SAP addition (i.e. neither grain size nor content).

Fracture Behaviour of Modified Spruce Wood: A Study Using Linear and Non Linear Fracture Mechanics

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Alexander Reiterer ◽  
Gerhard Sinn
Keyword(s):  
Fracture Energy ◽  
Heat Treatments ◽  
Critical Stress Intensity Factor ◽  
Mode I ◽  
Mode Iii ◽  
Fracture Properties ◽  
Specific Fracture Energy ◽  
Wedge Splitting Test ◽  
Splitting Test ◽  
Specific Fracture

Summary The fracture properties of unmodified and modified (heat treatments under various conditions and acetylation) sprucewood are investigated using the wedge splitting test. Fracture parameters measured include critical stress intensity factor and specific fracture energy under Mode I loading and specific fracture energy under Mode III loading. The Mode I fracture properties are reduced by all kinds of modification. However, acetylation leads to a reduction of only 20%whereas heat treatments reduce the properties to a much greater extent, approximately 50%to 80%. The Mode III fracture properties are influenced less. SEM pictures of the fracture surfaces support the described findings.

scholarly journals Vibrated Concrete vs. Self-Compacting Concrete: Comparison of Fracture Mechanics Properties

2014 ◽  
Vol 601 ◽  
pp. 199-202
Author(s):  
Sara Korte ◽  
Veerle Boel ◽  
Wouter de Corte ◽  
Geert de Schutter
Keyword(s):  
Fracture Mechanics ◽  
Mouth Opening ◽  
Bending Test ◽  
Crack Mouth Opening Displacement ◽  
Self Compacting Concrete ◽  
Opening Displacement ◽  
Three Point Bending ◽  
Fracture Parameters ◽  
Wedge Splitting Test ◽  
Splitting Test

This study focuses on the fracture mechanics aspect of self-compacting concrete, compared to vibrated concrete. The most commonly used experiments to investigate the toughness and cracking behaviour of concrete are the three-point bending test (3PBT) on small, notched beams, and the wedge-splitting test (WST) on cubic samples with guiding groove and starter notch. From the resulting P-CMOD curves (applied load versus crack mouth opening displacement), different fracture parameters, such as fracture energy and fracture toughness, can be extracted. Moreover, using inverse analysis, the σ-w relationship (tensile stress versus crack width) can be derived. This paper lists the results of a series of tests on samples, made of VC, SCC of equal strength, and SCC with identical w/c factor. Subsequently, a comparison of the mechanical characteristics is made, revealing important differences regarding several fracture parameters.

Evaluation of Steel Slag Fine Aggregate in Hot-Mix Asphalt Mixtures

1997 ◽  
Vol 1583 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Prithvi S. Kandhal ◽  
Gary L. Hoffman
Keyword(s):  
Hot Mix Asphalt ◽  
Coarse Aggregate ◽  
Steel Slag ◽  
Hot Water ◽  
Test Method ◽  
Fine Aggregate ◽  
Limestone Aggregate ◽  
Aggregate Fraction ◽  
Water Conditioning ◽  
Test Criteria

Since a considerable amount of steel slag is produced in the southwestern part of Pennsylvania around Pittsburgh, where natural fine aggregate sources are limited, an evaluation was undertaken to determine the feasibility of using “cured” steel slag fine aggregate in hot-mix asphalt (HMA) mixtures. The objectives of this work were to (1) correlate fine aggregate expansions to the “parent” coarse aggregate expansions, (2) determine properties of dense-graded Pennsylvania ID-2 wearing coarse mixtures made with various sources of steel slag and crushed limestone fine aggregate, and (3) recommend appropriate specifications and test criteria for implementing the use of steel slag fine aggregate, if justifiable. Expansive characteristics of the steel slag aggregates were determined by Pennsylvania Test Method 130. HMA mixtures made with steel slag aggregates and limestone aggregate (control) were subjected to hot-water conditioning and Lottman freeze-and-thaw conditioning to determine potential problems, such as swell and moisture-induced damage. An excellent correlation existed between the average total expansion of the fine aggregate fraction and that of the “parent” coarse aggregate. No significant problems with swell and moisture-induced damage were noted in HMA mixtures containing steel slag fine aggregate and limestone coarse aggregate. Specifications and test criteria were recommended for the use of steel slag fine aggregate in HMA mixtures.

scholarly journals FRACTURE OF CONCRETE CONTAINING CRUMB RUBBER

2013 ◽  
Vol 19 (3) ◽  
pp. 447-455 ◽  
Author(s):  
Audrius Grinys ◽  
Henrikas Sivilevičius ◽  
Darius Pupeikis ◽  
Ernestas Ivanauskas
Keyword(s):  
Fracture Energy ◽  
Mouth Opening ◽  
Crumb Rubber ◽  
Crack Mouth Opening Displacement ◽  
Concrete Fracture ◽  
Opening Displacement ◽  
Polypropylene Fibres ◽  
Abrupt Decrease ◽  
Resistance To Stress ◽  
Maximum Stresses

Every year, colossal amounts of used and non-biodegradable rubber tyres are accumulated in the world. Experience shows that the most efficient way to increase the concrete fracture energy G F (N/m) is to use metal or polypropylene fibres. The optimal content of fibre increases concrete resistance to stress (especially tensile stress under bending force). Concrete fracture is not brittle; concrete continues deforming after maximum stresses and is able to resist certain stresses, there is no abrupt decrease in loading. The research has proved that crumb rubber can be used in concretes as an alternative to metal and polypropylene fibres. The investigation has found that rubber waste additives, through their specific properties can partly take up tensile stresses in concrete and make the concrete fracture more plastic; besides, such concrete requires a significantly higher fracture energy and concrete samples can withstand much higher residual strength at 500 µm crack mouth opening displacement (CMOD) and deflection.

scholarly journals Advanced Evaluation of the Freeze–Thaw Damage of Concrete Based on the Fracture Tests

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6378
Author(s):  
Barbara Kucharczyková ◽  
Hana Šimonová ◽  
Dalibor Kocáb ◽  
Libor Topolář
Keyword(s):  
Peak Load ◽  
Mouth Opening ◽  
Crack Mouth Opening Displacement ◽  
Experimental Program ◽  
Crack Model ◽  
Test Evaluation ◽  
Fracture Test ◽  
Opening Displacement ◽  
Freeze Thaw ◽  
Fracture Tests

This paper presents the results of an experimental program aimed at the assessment of the freeze–thaw (F–T) resistance of concrete based on the evaluation of fracture tests accompanied by acoustic emission measurements. Two concretes of similar mechanical characteristics were manufactured for the experiment. The main difference between the C1 and C2 concrete was in the total number of air voids and in the A300 parameter, where both parameters were higher for C1 by about 35% and 52%, respectively. The evaluation of the fracture characteristics was performed on the basis of experimentally recorded load–deflection and load–crack mouth opening displacement diagrams using two different approaches: linear fracture mechanics completed with the effective crack model and the double-K model. The results show that both approaches gave similar results, especially if the nonlinear behavior before the peak load was considered. According to the results, it can be stated that continuous AE measurement is beneficial for the assessment of the extent of concrete deterioration, and it suitably supplements the fracture test evaluation. A comparison of the results of fracture tests with the resonance method and splitting tensile strength test shows that all testing methods led to the same conclusion, i.e., the C1 concrete was more F–T-resistant than C2. However, the fracture test evaluation provided more detailed information about the internal structure deterioration due to the F–T exposure.

Sign in / Sign up

Export Citation Format

Share Document