The Influence of Pore Structure on the Properties of Cement Paste: Initial Observations about Research-in-progress

1988 ◽  
Vol 137 ◽  
Author(s):  
D. A. Lange ◽  
H. M. Jennings ◽  
S. P. Shah
Keyword(s):  
Pore Structure ◽  
Fracture Energy ◽  
Optical Microscopy ◽  
Cement Paste ◽  
Material Properties ◽  
Direct Method ◽  
Total Porosity ◽  
Pore Geometry ◽  
Method Of Measurement ◽  
A Direct Method

AbstractInitial observations of the influence of pore structure on material properties of cement paste are described. The total porosity is held constant and pore structure is altered by use of a superplasticizer. Corresponding changes in strength and fracture energy are observed. Changes in the cement paste pore structure are evaluated by analysis of images obtained by optical microscopy. The technique is a direct method of measurement that avoids assumptions about pore geometry.

The Influence of Pore-Strucrure on the Campressive Strength of Hardened Cement Paste

1984 ◽  
Vol 42 ◽  
Author(s):  
Huang Yiun-Yuan ◽  
Ding Wei ◽  
Lu Ping
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Structure ◽  
Cement Paste ◽  
Total Porosity ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
New Information ◽  
The Relationship ◽  
Empirical Constants

AbstractThe pore-structure strongly influences the carpressive strength of hardened cement paste (hcp) and other porous materials, as well as other mechanical properties. The simplest but most currently used expression representing the relationship between the pore-structure and compressive strength is fram Balshin: σ = σ0 (l-P)A, in which only the total porosity P is involved as a single parameter and σ0 and A are empirical constants. The influence of pore size distribution and pore shapes etc. are not considered.The authors introduce second parameter w - the factor of relative specific surface area of the pores other than the total porosity P into consideration and a new expression is proposed:σc=K11-p/1+2p(K2(1-p))K3w+K4 all the constants K1 - K4 can be determined experimentally. By using of this expression the new information relating the influence of pore-structure on the caopressive strength of hcp can be predicted.

scholarly journals Relationship between Pore Structure and Chloride Ion Diffusivity in Cementitious Materials

2018 ◽  
Author(s):  
Yuya Sakai
Keyword(s):  
Pore Structure ◽  
Cement Paste ◽  
Pore Diameter ◽  
Chloride Ion ◽  
Total Porosity ◽  
Cementitious Materials ◽  
The Other ◽  
Diffusion Test ◽  
Other Hand ◽  
And Diffusion

In this study, literature on pore structure and chloride ion diffusivity was collected to investigate the correlation of pore structure indicators with diffusivity. Good correlation between total porosity and chloride ion diffusivity was found when the samples did not contain admixture materials and diffusion test was conducted without acceleration. Pore diameter indicators did not correlate with diffusivity. The diffusivity of cement paste was reduced by admixture materials compared to that without admixture materials even if the total porosity is the same. On the other hand, the diffusivity of concrete was not reduced by admixture materials.

Nonaxisymmetric Mechanical and Thermal Stresses in FGPPM Hollow Cylinder

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
M. Jabbari ◽  
M. Meshkini ◽  
M. R. Eslami
Keyword(s):  
Power Law ◽  
Material Properties ◽  
Heat Conduction Equation ◽  
Thermal Stresses ◽  
Direct Method ◽  
Functionally Graded ◽  
Complex Fourier Series ◽  
Thick Cylinder ◽  
A Direct Method ◽  
Radial Variable

In this paper, the general solution of steady-state 2D nonaxisymmetric mechanical and thermal stresses and electrical and mechanical displacements of a hollow thick cylinder made of fluid-saturated functionally graded porous piezoelectric material (FGPPM) is presented. The general form of thermal and mechanical boundary conditions is considered on the inside and outside surfaces. A direct method is used to solve the heat conduction equation and the nonhomogenous system of partial differential Navier equations, using the complex Fourier series and the power law functions method. The material properties, except Poisson's ratio, are assumed to depend on the radial variable and they are expressed as power law functions along the radial direction.

Influence of Pore Structure on Chloride Distribution in Surface Layer of Cement Paste under Cyclic Wet-Dry Condition

2018 ◽  
Vol 875 ◽  
pp. 165-173
Author(s):  
Hong Lei Chang ◽  
Song Mu ◽  
Ya Ya Du ◽  
Li Yang
Keyword(s):  
Surface Layer ◽  
Pore Structure ◽  
Cement Paste ◽  
Pore Diameter ◽  
Total Porosity ◽  
Chloride Content ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Chloride Profiles ◽  
Peak Value

This research focuses on influence of pore structure on chloride distribution in surface layer of cement paste under cyclic wet-dry condition. The results of chloride distribution reveal that drying and wetting cycles can lead to a peak value of chloride content (Cmax) occurring in surface layer of cement paste. Cmax increases with the increase of W/C. While the depth (Δx) at which Cmax appears does not show a regular change. Moreover, Cmax should be used to predict service life of concrete structures when Cmax appears in the chloride profiles. For the influence of pore structure, there exists an obvious hyperbolic relationship between chloride diffusion coefficient (D), Cmax and pore structure parameters. D and Cmax increase with total porosity and the most probable pore diameter, decrease with tortuosity, and stabilize gradually. And the most probable pore diameter has the most significant impact on D and Cmax. In addition, XRD and SEM-EDS results indicate that the deposition of Friedel’s salt results in the formation of more inkbottle shaped pores, which may cause the appearance of Cmax under cyclic drying-wetting conditions due to hysteretic moisture effect.

Sign in / Sign up

Export Citation Format

Share Document