Matlab Image Processing Technique and Application in Pore Structure Characterization of Hardened Cement Pastes

2013 ◽  
Vol 785-786 ◽  
pp. 1374-1379 ◽  
Author(s):  
An Qun Lu ◽  
Shou Zhi Zhang ◽  
Qian Tian
Keyword(s):  
Image Processing ◽  
Pore Structure ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Hardened Cement ◽  
Analysis Method ◽  
Image Analysis Method ◽  
Cement Pastes ◽  
Backscattered Electron ◽  
Hardened Cement Pastes

Based on Matlab image processing technique and backscattered electron image analysis method, a characterization method is set up to make quantitative analysis on pore structure of hardened cement pastes. Adopt Matlab to acquire images, and carry out gradation and binarization processing for them; use the combination method of local threshold segmentation and histogram segmentation to obtain pore structure characteristics. The results showed that evolution law of pore structure of fly ash cement pastes via Matlab image analysis method is similar to the conclusion obtained through BET and DVS. Selecting different angle of backscattered electron images in the same sample, its statistic results are more representative.

Pore Structure and Chloride Ion Transport Mechanisms in Concrete

2006 ◽  
Vol 302-303 ◽  
pp. 528-535
Author(s):  
Cai Jun Shi ◽  
De Hua Deng ◽  
You Jun Xie
Keyword(s):  
Pore Structure ◽  
Chloride Ion ◽  
Engineering Properties ◽  
Hardened Cement ◽  
Transport Mechanisms ◽  
Reinforced Concrete Structure ◽  
Cement Pastes ◽  
Capillary Suction ◽  
Structure Characteristics ◽  
Hardened Cement Pastes

Hardened cement paste and concrete are porous materials. Most engineering properties of hardened cement pastes and concrete, such as strength, shrinkage, permeability, etc., are influenced or controlled by their pore structure characteristics. The ingress of chloride ion into concrete can cause steel corrosion and damage of steel reinforced concrete structure. This paper reviews the pore structure characteristics and transport mechanisms of chloride ion, such as hydrostatic advection, capillary suction, diffusion, thermal migration and electrical migration, in hardened cement pastes and concrete.

Relationship between compressive strength and pore structure of hardened cement pastes

1997 ◽  
Vol 9 (33) ◽  
pp. 25-30 ◽  
Author(s):  
T. Takahashi ◽  
M. Yamamoto ◽  
K. Ioku ◽  
S. Goto
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Hardened Cement Pastes

scholarly journals Studies of Surface Area and Pore Structure on Portland Cement Produced in Bajil and Amran, Yemen

2008 ◽  
Vol 13 ◽  
pp. 13
Author(s):  
A.M. Saad ◽  
Abdul-Basit A. Saleh ◽  
Fatima A. Al-Kadri ◽  
Abdulla S. Babaqi ◽  
Abdulla A. Basissa ◽  
...  
Keyword(s):  
Portland Cement ◽  
Pore Structure ◽  
Hysteresis Loops ◽  
Hardened Cement ◽  
Pore System ◽  
Nitrogen Gas ◽  
Time Intervals ◽  
Cement Pastes ◽  
Adsorption Desorption ◽  
Hardened Cement Pastes

Portland cement pastes of various porosities were prepared using water/cement ratios of 0.30, 0.35, 0.40, 0.45, 0.50 and 0.55; and were hydrated for various time intervals ranging from 0.021 to 28 days.  Pore structure and VL–t plots (plots of volume vs. thickness) of the hardened cement pastes were measured using nitrogen gas as the adsorbate. The results were found to be related to the mechanism of hydration as controlled by the pore system of the hardened pastes. Type ІІ adsorption isotherms of nitrogen were obtained for all hardened cement pastes. The adsorption-desorption isotherms indicated the existence of closed hysteresis loops for most of the investigated samples and in some other cases, these isotherms were fully reversible.  

Influences of Ground Limestone Fineness on the Properties of Cement-Based Materials

2012 ◽  
Vol 517 ◽  
pp. 403-410
Author(s):  
Jia Xiao ◽  
Bao Guo Ma ◽  
Rong Zhen Dong ◽  
Cai Yun Xu
Keyword(s):  
Pore Structure ◽  
Mercury Intrusion Porosimetry ◽  
Cement Mortar ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Mercury Intrusion ◽  
Setting Times ◽  
Cement Based Materials ◽  
Hardened Cement Pastes ◽  
Ground Limestone

The effect of ground limestone fineness on the properties and mechanism of cement-based composite materials was investigated. The setting times, fluidity and strength of cement mortar were measured. In order to identify the mechanism effect of ground limestone fineness on the microstructure of the hardened cement pastes, microstructure analyses such as calorimetry analysis and Mercury Intrusion Porosimetry (MIP) were also performed. Experimental results indicated that the setting times are shortened, and the fluidity and strength of cement mortar are improved with the ground limestone fineness increases. The increase of the ground limestone fineness can effectively inhibit the pore structure of hardened paste, which due to mortar and paste samples incorporating replacement levels of ground limestone, and improve the pore structure of hardened paste.

scholarly journals Effect of Some Acrylate—Poly(Ethylene Glycol) Copolymers as Superplasticizers on the Mechanical and Surface Properties of Portland Cement Pastes

2005 ◽  
Vol 23 (3) ◽  
pp. 245-254 ◽  
Author(s):  
S.A. Abo-El-Enein ◽  
S. Hanafi ◽  
F.I. El-Hosiny ◽  
El-Said H.M. El-Mosallamy ◽  
M.S. Amin
Keyword(s):  
Ethylene Glycol ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Mechanical Characteristics ◽  
Hardened Cement ◽  
Poly Ethylene Glycol ◽  
Cement Pastes ◽  
Surface Areas ◽  
Poly Ethylene ◽  
Hardened Cement Pastes

Ordinary Portland cement (OPC) pastes with added superplasticizer were made using water/cement weight ratios of standard consistency. Three types of superplasticizer based on acrylate—poly(ethylene glycol) copolymers were used. The pastes were hydrated for various time lengths and the mechanical characteristics of the hardened cement pastes were studied and related to their pore structures. It was found that the addition of the superplasticizers to OPC improved the mechanical properties of the hardened pastes for all hydration lengths. The addition of such superplasticizers to OPC resulted in a decrease in the specific surface areas and total pore volumes of the hardened superplasticized cement pastes relative to the corresponding hardened neat cement pastes.

Assessment of Anhydrous Ethanol Extraction to Determine the Ionic Concentration of Hardened Cement Pastes

2010 ◽  
Vol 177 ◽  
pp. 506-509 ◽  
Author(s):  
Man Jian Wu ◽  
Wu Yao ◽  
Wei Wang ◽  
Yong Qi Wei
Keyword(s):  
Pore Solution ◽  
Ph Value ◽  
Ionic Concentration ◽  
Anhydrous Ethanol ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Ethanol Extraction ◽  
Alkali Ions ◽  
Ph Values ◽  
Hardened Cement Pastes

A new method involving the extraction of various ions from hardened cement pastes by anhydrous ethanol is presented to determine the pH value and ionic concentration during the first 28 days. The volume content of pore solution extracted by ethanol in the leachate reached 12% or above and the pH values calculated by alkali ions are more than 12, even up to 12.73. The results were compared with those from parallel, conventional pore water expression experiments. All of these comparisons verified the feasibility of the proposed method. However, the application of this method to pore solution analysis needs further improvement.

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