Fracture properties of high-performance concrete containing fly ash

2012 ◽  
Vol 226 (2) ◽  
pp. 170-176 ◽  
Author(s):  
P Zhang ◽  
Q Li ◽  
H Zhang
Keyword(s):  
Fly Ash ◽  
Crack Opening Displacement ◽  
High Performance ◽  
High Performance Concrete ◽  
Crack Opening ◽  
Ash Content ◽  
Crack Mouth Opening Displacement ◽  
Opening Displacement ◽  
Fracture Properties ◽  
Fracture Parameters

A parametric experimental study has been conducted to investigate the effect of fly ash on the fracture properties of high-performance concrete (HPC), with four fly ash contents used. By means of three-point bending method, the fracture toughness, fracture energy, effective crack length, critical crack opening displacement, and maximum crack opening displacement of the specimen were measured, respectively. The results indicate that fly ash has great improvement on the fracture parameters, and these fracture parameters gradually increase when the content of fly ash increases from 10 per cent to 20 per cent. However, these fracture parameters begin to decrease after the fly ash content exceeds 20 per cent. Besides, as the fly ash content increases from 10 per cent to 20 per cent, the relational curves between the vertical load and the mid-span deflection ( PV– δ), crack mouth opening displacement ( PV– CMOD), and crack tip opening displacement ( PV– CTOD) become plumper and plumper, which indicates that the capability of HPC containing fly ash to resist crack propagation is becoming stronger and stronger, while the curves become shriveled after the fly ash content exceeds 20 per cent. The contribution of fly ash on the fracture properties of HPC containing fly ash seems to be performed only when the fly ash content does not exceed 20 per cent.

Effect of polypropylene fiber on fracture properties of high-performance concrete composites

2012 ◽  
Vol 19 (4) ◽  
pp. 407-414 ◽  
Author(s):  
Peng Zhang ◽  
Qing-fu Li
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Fiber Volume Fraction ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Crack Opening ◽  
Polypropylene Fiber ◽  
Fiber Volume ◽  
Opening Displacement ◽  
Fracture Parameters

AbstractA parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the workability and fracture properties of high-performance concrete (HPC) composites containing fly ash and silica fume, with the five fiber volume fractions (0.04%, 0.06%, 0.08%, 0.1%, and 0.12%) used. The results indicate that the addition of polypropylene fiber decreases the workability of the HPC composites containing fly ash and silica fume. With the increase in the fiber volume fraction, both of the slump and the slump flow decrease gradually. Furthermore, the addition of polypropylene fiber has greatly improved the fracture parameters of concrete composite containing 15% fly ash and 6% silica fume, such as fracture toughness, fracture energy, effective crack length, maximum midspan deflection, the critical crack opening displacement, and the maximum crack opening displacement of the three-point bending beam specimens. When the fiber volume fraction increases from 0% to 0.12%, the fracture parameters increase gradually. The variation rules of the fracture parameters indicate that the capability of the polypropylene fiber to resist the crack propagation of the concrete composite containing 15% fly ash and 6% silica fume is becoming stronger and stronger with the increase in fiber volume fraction with the fiber volume fraction not above 0.12%.

Test for Crack Opening Displacement of Steel Fiber Reinforced Concrete under Three-Point Bending

2010 ◽  
Vol 36 ◽  
pp. 157-161 ◽  
Author(s):  
Tin Gyi Zhang ◽  
Yuan Bao Leng ◽  
Dan Ying Gao
Keyword(s):  
Crack Opening Displacement ◽  
Crack Opening ◽  
Mouth Opening ◽  
Crack Tip ◽  
Crack Mouth Opening Displacement ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Critical Crack ◽  
Critical Crack Opening ◽  
Crack Tip Opening

Based on the principle of electrical measurement method, the clip gauge was made to measure the crack opening displacement (COD).Through the three-point bending test on the specimens of steel fiber reinforced high strength concrete (SFHSC), the effect of the fiber volume fraction (ρf) upon the critical crack opening displacement (the critical crack tip opening displacement and the critical crack mouth opening displacement) was studied. The result shows that the effect of ρf on mouth-tip ratio (the ratio of critical crack mouth opening displacement to critical crack tip opening displacement) can reflect its effect upon the critical crack opening displacement. According to the geometrical relationship between the initial crack length and the critical crack opening displacement，calculation method for the initial crack length was proposed. Based on the test result, the formula was established for calculating the critical crack tip opening displacement.

Experimental Study on Workability and Strength of Green High Performance Concrete with High Volume Fly Ash

2013 ◽  
Vol 859 ◽  
pp. 52-55 ◽  
Author(s):  
Yong Qiang Ma
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
High Volume ◽  
Ash Content ◽  
Splitting Tensile Strength ◽  
Binder Ratio ◽  
Water Binder Ratio

A great deal of experiments have been carried out in this study to reveal the effect of the water-binder ratio and fly ash content on the workability and strengths of GHPC (green high performance concrete). The workability of GHPC was evaluated by slump and slump flow. The strengths include compressive strength and splitting tensile strength. The results indicate that the increase of water-binder ratio can improve the workability of GHPC, however the strengths of GHPC were decreased with the increase of water-binder ratio. When the fly ash content is lower than 40%, the increase in fly ash content has positive effect on workability of GHPC, while the workability begins to decrease after the fly ash content is more than 40%. The addition of fly ash in GHPC has adverse effect on the strengths, and there is a tendency of decrease in the compressive strength and splitting tensile strength of GHPC with the increase of fly ash content.

scholarly journals Fracture parameters of fly ash geopolymer mortars with carbon black and graphite filler

2021 ◽  
Vol 1205 (1) ◽  
pp. 012019
Author(s):  
H Simonova ◽  
C Mizerova ◽  
P Rovnanik ◽  
M Lipowczan ◽  
P Schmid
Keyword(s):  
Fly Ash ◽  
Carbon Black ◽  
Mouth Opening ◽  
Bending Test ◽  
Crack Mouth Opening Displacement ◽  
Crack Model ◽  
Vertical Force ◽  
Opening Displacement ◽  
Mechanical Fracture ◽  
Fracture Parameters

Abstract In this study, the effect of carbon black and graphite filler on the crack initiation and fracture parameters of fly ash geopolymer mortar is investigated. The carbon black was added in the amount of 0.5 and 1.0% and graphite powder in the amount of 5 and 10% relative to the fly ash mass. The reference mixture without any filler was also prepared. The fracture characteristics were determined based on the results of the three-point bending test of prismatic specimens provided with an initial central edge notch. The fracture experiments were conducted at the age of 48 days. The vertical force (F), the displacement measured in the middle of the span length (d), and the crack mouth opening displacement (CMOD) were continuously recorded during the test. The records of fracture tests were subsequently evaluated using the effective crack model, work-of-fracture method, and double-K fracture model. The addition of both fine fillers led to a decrease in monitored mechanical fracture parameters in comparison with reference mortar.

Study on Performance of High-Performance Concrete Made with Fly Ash and Polypropylene Fiber

2011 ◽  
Vol 99-100 ◽  
pp. 1027-1030
Author(s):  
Lan Fang Zhang ◽  
Rui Yan Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Significant Influence ◽  
High Performance ◽  
High Performance Concrete ◽  
Impact Resistance ◽  
Polypropylene Fiber ◽  
Drying Shrinkage ◽  
Ash Content ◽  
Fiber Content

High-performance concrete was made with fly ash and polypropylene fiber, the study shows that when fly ash content was 20% and polypropylene fiber was 0.6~1.2kg/m3, it had no significant influence on the workability of concrete, however the changes of 28d compressive strength and drying shrinkage of concrete are within 10%, but it can reduce brittle and improve toughness, and impact resistance of concrete is improved obviously, when polypropylene fiber content was 0.9kg/m3, it can improve over three times.

scholarly journals Simplified equations for determining double-k fracture parameters of concrete for compact tension test

2022 ◽  
Vol 10 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Rajendra K. Choubey ◽  
Shailendra Kumar
Keyword(s):  
Crack Opening Displacement ◽  
Crack Opening ◽  
Peak Load ◽  
Relative Size ◽  
Compact Tension ◽  
Crack Model ◽  
Opening Displacement ◽  
Fictitious Crack Model ◽  
Fracture Parameters ◽  
Fictitious Crack

Polynomial equations in non-dimensional form for various fracture parameters of double-K fracture model for compact tension specimen have been derived and presented in this paper. These equations can be used for computing different double-K fracture parameters of concrete for known material properties and specimen size having relative size of initial crack length of 0.3 without involving much complexity in numerical computations. Values of peak load and corresponding crack opening displacement as necessary to compute the double-K fracture parameters of concrete have been derived from the established fictitious crack model in the present study. A simplified equation in non-dimensional form between peak load and critical crack opening displacement as obtained from a fictitious crack model has also been presented.

Sign in / Sign up

Export Citation Format

Share Document