Chemical properties of pore solution of hardened cement pastes with mineral additions

2020 ◽  
pp. 1-11 ◽  
Author(s):  
Rachid Cherif ◽  
Ameur El Amine Hamami ◽  
Abdelkarim Aït-Mokhtar ◽  
Rafat Siddique
Keyword(s):  
Pore Solution ◽  
Chemical Properties ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Mineral Additions ◽  
Hardened 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.

Influence of Fly Ash on Alkalinity of Pore Solution and Microstructure Characteristics of Hardened Cement Pastes

2012 ◽  
Vol 253-255 ◽  
pp. 322-325 ◽  
Author(s):  
Jian Jun Yan ◽  
Xiang Li ◽  
Hua Quan Yang
Keyword(s):  
Fly Ash ◽  
Pore Solution ◽  
Cementitious Material ◽  
Ex Situ ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Microstructure Characteristics ◽  
Hardened Cement Pastes ◽  
Very High ◽  
Reaction Degree

Influence of fly ash on alkalinity of pore solution and microstructure characteristics of hardened cement pastes were investigated by means of ex-situ leaching (ESL), MIP and SEM. The results reveal that the decline of alkalinity of pore solution is not endless, even though the contents of fly ash in fly ash-cement(FC) pastes is very high(65%).The incorporation of fly ash in proper ratios could increase the ratio of harmless pores and improve the microstructure of the FC pastes. Ca(OH)2 was not consumed heavily or exhausted when cementitious material was hydrated due to the low reaction degree of fly ash.

Assessment of Ultrasonic-Ethanol Extraction to Determine the pH Value of Hardened Cement Pastes

2011 ◽  
Vol 492 ◽  
pp. 451-454
Author(s):  
Xiao Ming Xing ◽  
Wu Yao
Keyword(s):  
Pore Solution ◽  
Ph Value ◽  
Anhydrous Ethanol ◽  
Hardened Cement ◽  
Simple Method ◽  
Cement Pastes ◽  
Ethanol Extraction ◽  
Ph Values ◽  
Hardened Cement Pastes ◽  
Variation Tendency

A simple method is presented to extract the pore solution of hardened cement pastes during the first 28 days and to measure the pH value, which is dependent on anhydrous-ethanol extraction (AEE) and improved by the assistance of ultrasonic vibration generator. The results were compared with the pore water expression (PWE) and anhydrous ethanol extraction through observing the variation tendency of pH values along with time and different water-cement ratios (w/c). The study showed that as w/c decreased, the pH value had a rising tendency; the density of [OH-] extracted by ultrasonic-ethanol extraction (UEE) method is 4-5 times higher than that by AEE method, which indicates the feasibility of UEE method.

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.

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