Effect of Aggregate Volume Fraction on the Charge Passed of Mortar and Concrete

2009 ◽  
Vol 405-406 ◽  
pp. 283-288 ◽  
Author(s):  
Quan Lin Niu ◽  
Chong Zhi Li
Keyword(s):  
Penetration Depth ◽  
Volume Fraction ◽  
Low Permeability ◽  
Chloride Permeability ◽  
Volume Fractions ◽  
Aggregate Fraction ◽  
Low Charge ◽  
Astm C1202 ◽  
The Relationship ◽  
Cl Permeability

Charge passed of mortars with different aggregate volume fractions was tested according to ASTM C1202, and the differential expression of the Ohm law was introduced to explain the relationship between charge passed data and aggregate fractions.Cl- penetration depth of the corresponding mortars and concretes was measured to illustrate the influence of the aggregate volume fraction on their chloride permeability. It was shown that the charge passed of mortar was negatively correlated with aggregate volume fractions, and high aggregate fraction bearing concrete with low charge passed did not necessarily mean low permeability. As a result, the influence of aggregate fraction on charge passed should be taken into consideration when charge passed data was employed to evaluate Cl- permeability of concrete.

scholarly journals Analysis of the Aggregate Effect on the Compressive Strength of Concrete Using Dune Sand

2021 ◽  
Vol 11 (4) ◽  
pp. 1952
Author(s):  
Euibae Lee ◽  
Jeongwon Ko ◽  
Jaekang Yoo ◽  
Sangjun Park ◽  
Jeongsoo Nam
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Volume Fraction ◽  
Fine Aggregate ◽  
Dune Sand ◽  
Effect Factor ◽  
Volume Fractions ◽  
Aggregate Effect ◽  
Compressive Strength Of Concrete ◽  
The Relationship

In this study, the compressive strengths of concrete were investigated based on water content and aggregate volume fractions, comprising dune sand (DS), crushed sand (CS), and coarse aggregate (CA), for different ages. Experimental data were used to analyze the effects of the volume fraction changes of aggregates on the compressive strength. The compressive strength of concrete increases until the volumetric DS to fine aggregate (FA) ratio (DS/FA ratio) reaches 20%, after which it decreases. The relationship between changes in compressive strength and aggregate volume fractions was analyzed considering the effect factor of each aggregate on the compressive strength and at 2 conditions: (1) 0 < DS < CS < CA and (2) 0 < CA < CS < DS. For condition (1), when the effect factor of CA = 1, those of DS and CS were within 0.04–0.83 and 0.72–0.92, respectively, for all mixtures. For condition (2), when the effect factor of DS = 1, those of CS and CA were within 0.68–0.80 and 0.02–0.79, respectively.

Study on the Influence of Painting Processes on the Protective Property of Concrete Coating

2012 ◽  
Vol 509 ◽  
pp. 88-92
Author(s):  
Yan Zheng ◽  
Qian Jin Mao ◽  
Ya Li Wang ◽  
Zi Ming Wang ◽  
Su Ping Cui
Keyword(s):  
Penetration Depth ◽  
Chloride Ion ◽  
Chloride Permeability ◽  
Acrylic Emulsion ◽  
Effective Measure ◽  
Water Based ◽  
Protective Performance ◽  
The Impact ◽  
The Relationship ◽  
Durability Of Concrete

With the development of construction project the durability of concrete is becoming more and more prominent, and surface coating is an effective measure to enhance the durability of concrete. Water-based silicone acrylic emulsion coating and water-based fluorocarbon resin coating were chose as prime and topcoat respectively. The impact of the coating’s thickness and viscosity on the durability of concrete and the relationship between the viscosity of the coating and its penetration depth were testified by chloride ion permeability-resistance property of concrete. The results show that thickness is proportional to the protective performance of the coating, and the penetration depth highly depends on viscosity. And the result of coating-4 viscosity method shows that samples with viscosity between 15 and 25 seconds have better chloride permeability resistance.

scholarly journals An Intrinsic Material Tailoring Approach for Functionally Graded Axisymmetric Hollow Bodies Under Plane Elasticity

2021 ◽  
Author(s):  
Hassan Mohamed Abdelalim Abdalla ◽  
Daniele Casagrande
Keyword(s):  
Optimization Problem ◽  
Volume Fraction ◽  
Minimum Principle ◽  
Equivalent Stress ◽  
Micromechanical Model ◽  
Plane Elasticity ◽  
Functionally Graded ◽  
Pontryagin Minimum Principle ◽  
Volume Fractions ◽  
Material Tailoring

AbstractOne of the main requirements in the design of structures made of functionally graded materials is their best response when used in an actual environment. This optimum behaviour may be achieved by searching for the optimal variation of the mechanical and physical properties along which the material compositionally grades. In the works available in the literature, the solution of such an optimization problem usually is obtained by searching for the values of the so called heterogeneity factors (characterizing the expression of the property variations) such that an objective function is minimized. Results, however, do not necessarily guarantee realistic structures and may give rise to unfeasible volume fractions if mapped into a micromechanical model. This paper is motivated by the confidence that a more intrinsic optimization problem should a priori consist in the search for the constituents’ volume fractions rather than tuning parameters for prefixed classes of property variations. Obtaining a solution for such a class of problem requires tools borrowed from dynamic optimization theory. More precisely, herein the so-called Pontryagin Minimum Principle is used, which leads to unexpected results in terms of the derivative of constituents’ volume fractions, regardless of the involved micromechanical model. In particular, along this line of investigation, the optimization problem for axisymmetric bodies subject to internal pressure and for which plane elasticity holds is formulated and analytically solved. The material is assumed to be functionally graded in the radial direction and the goal is to find the gradation that minimizes the maximum equivalent stress. A numerical example on internally pressurized functionally graded cylinders is also performed. The corresponding solution is found to perform better than volume fraction profiles commonly employed in the literature.

scholarly journals A Micro-mechanical Investigation of Empirical Models for the Effective Properties of Aligned Short-Fibre Composites

1995 ◽  
Vol 4 (1) ◽  
pp. 096369359500400
Author(s):  
T.D. Papathanasiou
Keyword(s):  
Aspect Ratio ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Fibre Volume ◽  
Short Fibre ◽  
Computational Results ◽  
Volume Fractions ◽  
Fibre Composites ◽  
Effective Tensile Modulus ◽  
Fibre Aspect Ratio

The predictions of the Halpin equation concerning the effect of fibre volume fraction and fibre aspect ratio on the effective tensile modulus of uniaxially aligned short-fibre composites are compared with computational experiments on three-dimensional, multiparticle composite samples. The method of boundary elements is used to model the mechanical behaviour of composite specimens consisting of up to 40 discrete aligned fibres randomly dispersed in an elastic matrix. Statistical averages of computational results relating the effective tensile modulus to the aspect ratio and volume fraction of the fibres are found to agree very well with the predictions of the Halpin equation for fibre aspect ratio up to 10 and fibre volume fractions up to 20%. Computational results seem to indicate that the predictions of the Halpin equation fall bellow those of micro-mechanical models at higher volume fractions.

Estimation of Interlayer Thickness in Inorganic Particulate-Filled Polymer Composites

2011 ◽  
Vol 24 (6) ◽  
pp. 777-788 ◽  
Author(s):  
J.Z. Liang
Keyword(s):  
Polymer Composites ◽  
Volume Fraction ◽  
Particle Diameter ◽  
Interfacial Structure ◽  
Interlayer Thickness ◽  
Filled Polymer ◽  
Mechanical And Physical Properties ◽  
The Relationship ◽  
Good Agreement

The structure of the interlayer between matrix and inclusions affect directly the mechanical and physical properties of inorganic particulate-filled polymer composites. The interlayer thickness is an important parameter for characterization of the interfacial structure. The effects of the interlayer between the filler particles and matrix on the mechanical properties of polymer composites were analyzed in this article. On the basis of a simplified model of interlayer, an expression for estimating the interlayer thickness ([Formula: see text]) was proposed. In addition, the relationship between the [Formula: see text] and the particle size and its concentration was discussed. The results showed that the calculations of the [Formula: see text] and thickness/particle diameter ratio ([Formula: see text]) increased nonlinearly with an increase of the volume fraction of the inclusions. Moreover, the predictions of [Formula: see text] and the relevant data reported in literature were compared, and good agreement was found between them.

Variant Selection in Zr Alloys: How Many Variants Generated from one Beta Grain?

2005 ◽  
Vol 105 ◽  
pp. 133-138 ◽  
Author(s):  
Pierre Barbéris ◽  
Frank Montheillet ◽  
Cédric Chauvy
Keyword(s):  
Elastic Energy ◽  
Volume Fraction ◽  
Variant Selection ◽  
Energy Minimum ◽  
Maximum Volume ◽  
Volume Fractions ◽  
Minimum Number ◽  
Simplifying Assumptions ◽  
Maximum Volume Fraction ◽  
Zr Alloys

The elastic energy of a set of the twelve variants generated during the b ® a transformation of zirconium, with volume fractions fi, i=1..12, is derived with simplifying assumptions and the conditions on the fi to reach the energy minimum are established analytically. The minimum number of variants needed to reach this minimum is shown to be 6, and in this case, the variants have very specific volume fractions. Another result is that the maximum volume fraction of any variant is 1/3.

The Influence of Multiple Inclusions on the Cauchy Stress of a Spherical Particle-Reinforced Composite Under Uniaxial Loading

2014 ◽  
Author(s):  
Ke Niu ◽  
Armin Abedini ◽  
Zengtao Chen
Keyword(s):  
Spherical Particle ◽  
Single Particle ◽  
Volume Fraction ◽  
Unit Cell ◽  
Spherical Particles ◽  
Uniaxial Tensile ◽  
Cauchy Stress ◽  
Particle Volume ◽  
Volume Fractions ◽  
Unit Cells

This paper investigates the influence of multiple inclusions on the Cauchy stress of a spherical particle-reinforced metal matrix composite (MMC) under uniaxial tensile loading condition. The approach of three-dimensional cubic multi-particle unit cell is used to investigate the 15 non-overlapping identical spherical particles which are randomly distributed in the unit cell. The coordinates of the center of each particle are calculated by using the Random Sequential Adsorption algorithm (RSA) to ensure its periodicity. The models with reinforcement volume fractions of 10%, 15%, 20% and 25% are evaluated by using the finite element method. The behaviour of Cauchy stress for each model is analyzed at a far-field strain of 5%. For each reinforcement volume fraction, four models with different particle spatial distributions are evaluated and averaged to achieve a more accurate result. At the same time, single-particle unit cell and analytical model were developed. The stress-strain curves of multi-particle unit cells are compared with single-particle unit cells and the tangent homogenization model coupled with the Mori-Tanaka method. Only little scatters were found between unit cells with the same particle volume fractions. Multi-particle unit cells predict higher response than single particle unit cells. As the volume fraction of reinforcements increases, the Cauchy stress of MMCs increases.

Performance of Bamboo Fiber Reinforced Composites: Mechanical Properties

2021 ◽  
Vol 879 ◽  
pp. 284-293
Author(s):  
Norliana Bakar ◽  
Siew Choo Chin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Vinyl Ester ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Bamboo Fiber ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Volume Fractions

Fiber Reinforced Polymer (FRP) made from synthetic fiber had been widely used for strengthening of reinforced concrete (RC) structures in the past decades. Due to its high cost, detrimental to the environment and human health, natural fiber composites becoming the current alternatives towards a green and environmental friendly material. This paper presents an investigation on the mechanical properties of bamboo fiber reinforced composite (BFRC) with different types of resins. The BFRC specimens were prepared by hand lay-up method using epoxy and vinyl-ester resins. Bamboo fiber volume fractions, 30%, 35%, 40%, 45% and 50% was experimentally investigated by conducting tensile and flexural test, respectively. Results showed that the tensile and flexural strength of bamboo fiber reinforced epoxy composite (BFREC) was 63.2% greater than the bamboo fiber reinforced vinyl-ester composite (BFRVC). It was found that 45% of bamboo fiber volume fraction on BFREC exhibited the highest tensile strength compared to other BFRECs. Meanwhile, 40% bamboo fiber volume fraction of BFRVC showed the highest tensile strength between bamboo fiber volume fractions for BFRC using vinyl-ester resin. Studies showed that epoxy-based BFRC exhibited excellent results compared to the vinyl-ester-based composite. Further studies are required on using BFRC epoxy-based composite in various structural applications and strengthening purposes.

scholarly journals Simulation of the Effect of Oil Volume Fractions in an Oil-Water Flows Along a Circular Pipe: A Finite Element Approach

2018 ◽  
Vol 10 (5) ◽  
pp. 19
Author(s):  
Ferdusee Akter ◽  
Md. Bhuyan ◽  
Ujjwal Deb
Keyword(s):  
Finite Element ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Galerkin Approximation ◽  
Computational Domain ◽  
Two Phase Flows ◽  
Two Phase ◽  
Volume Fractions ◽  
Oil In Water ◽  
Element Approach

Two phase flows in pipelines are very common in industries for the oil transportations. The aim of our work is to observe the effect of oil volume fraction in the oil in water two phase flows. The study has been accomplished using a computational model which is based on a Finite Element Method (FEM) named Galerkin approximation. The velocity profiles and volume fractions are performed by numerical simulations and we have considered the COMSOL Multiphysics Software version 4.2a for our simulation. The computational domain is 8m in length and 0.05m in radius. The results show that the velocity of the mixture decreases as the oil volume fraction increases. It should be noted that if we gradually increase the volume fractions of oil, the fluid velocity also changes and the saturated level of the volume fraction is 22.3%.

Experimental Investigation on Rotary Punching by the Compression of Polyurethane Pad

2014 ◽  
Vol 941-944 ◽  
pp. 1802-1807 ◽  
Author(s):  
Qian Liu ◽  
Jing Tao Han ◽  
Jing Liu ◽  
Xiao Xiong Wang
Keyword(s):  
Penetration Depth ◽  
Process Parameters ◽  
High Load ◽  
Large Area ◽  
Bear Capacity ◽  
Hole Edge ◽  
Quality Degradation ◽  
Series Of Experiments ◽  
Blanking Process ◽  
The Relationship

Rotary punching is a sheet metal blanking process which utilizes shearing tools fixed to a pair of rollers. The polyurethane pad is adopted as the die instead of rigid mold because it has the advantages of wide hardness range and high load-bear capacity. Due to the application of polyurethane pad, the surrounding region adjacent to the pierced hole will occur to plastically deform and deflect, which greatly differs from that in the conventional blanking. In this paper, the effects of blank material and thickness, polyurethane hardness, punch penetration depth on deformation behavior were mathematically analyzed and modeled, and then a series of experiments through varying process parameters were conducted to validate the relationship between process parameters and product quality. The degree of sample deflection was exactly measured by scanning electron microscope (SEM). The results show that the deformed area varies with different blank elongations and increases with increasing blank thickness for a given material. When polyurethane pad with low hardness level is employed, it results in large area deformation and quality degradation. Moreover, the deflection degree around the hole edge becomes more severe along with punch penetration, but the penetration depth along blank thickness is not in proportion to the amount of punch advancement.

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