Influence of limestone and slag on the pore structure of cement paste based on mercury intrusion porosimetry and water vapour sorption measurements

2014 ◽  
Vol 52 ◽  
pp. 52-58 ◽  
Author(s):  
Daman K. Panesar ◽  
James Francis
Keyword(s):  
Pore Structure ◽  
Water Vapour ◽  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Water Vapour Sorption ◽  
Mercury Intrusion ◽  
Vapour Sorption

Effect of Inorganic Salts on Pore Structure of Cement Paste

2009 ◽  
Vol 405-406 ◽  
pp. 378-383
Author(s):  
Wen Cui Yang ◽  
Yong Ge ◽  
Jie Yuan ◽  
Bao Sheng Zhang
Keyword(s):  
Pore Structure ◽  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Cold Weather ◽  
Inorganic Salts ◽  
Early Age ◽  
Concrete Durability ◽  
Mercury Intrusion ◽  
Concrete Shrinkage ◽  
Concrete Property

Inorganic salts are important admixtures usually used in cold weather concrete. As research basic of influence of salts on concrete durability, effects of inorganic salts on pore structure of cement paste were studied in this paper, and possible implications of concrete property with pore structure was also analyzed. Pore structure of paste added CaCl2, NaCl, Na2SO4, NaNO2, Ca(NO3)2 and Ca(NO2)2 curing for 3 days and 28 days were tested through mercury intrusion porosimetry (MIP). The results showed that no matter 0.3 or 0.5 water-cement ratio, the pores whose diameter <50nm in paste with salts increased at 3 days, which was harmful for the control of concrete shrinkage and cracking at early age. Adding Ca (NO3)2 increased coarse pores (>200nm) of paste at 3 days, but these coarse pores turned into fine pores and reduced significantly at 28 days. Adding NaCl and Na2SO4 into cement paste raised coarse pores with size>1000nm at 3 days and 28days, which were harmful for the pore structure.

scholarly journals Pore structure of mortars containing limestone powder and natural pozzolan assessed through mercury intrusion porosimetry and dynamic vapour sorption

2018 ◽  
Vol 199 ◽  
pp. 02020
Author(s):  
Natalia Alderete ◽  
Yury Villagrán ◽  
Arn Mignon ◽  
Didier Snoeck ◽  
Nele De Belie
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Mercury Intrusion Porosimetry ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Limestone Powder ◽  
Natural Pozzolan ◽  
Mercury Intrusion ◽  
Vapour Sorption ◽  
Wide Range

Pore structure characterization is a key aspect when studying the durability of cementitious materials. When supplementary cementitious materials (SCMs) are used changes in pore structure are expected, and the complexity of its analysis is increased. The purpose of this paper is to describe the pore structure variation of mortars with two types of SCMs: natural pozzolan from volcanic origin (NP), and limestone powder (LP). We tested mixes with cement replacements (in weight) of 20 % and 40% by NP, and 10 % and 20% by LP. To analyse the pore structure, two widely accepted and complementary techniques were applied: dynamic water vapour sorption (DVS) and mercury intrusion porosimetry (MIP). With the DVS data, the Barret-Joyner-Halenda (BJH) model was used for pore size distribution assessment. Calculations with the Dubinin-Radushkevich (DR) model were also made for the smallest pore size range. Tests were performed at 28 and 90 days. MIP and DVS allowed evaluating the effect of the studied SCMs on different pore size ranges. Both techniques provided comprehensive information over a wide range of pore sizes. The mix with 40 % of NP had the best evolution, showing a significant volume decrease in the mesopore range.

Modelling Pore Structure of Cement Based Material According to Continuous Network System

2014 ◽  
Vol 578-579 ◽  
pp. 1531-1537
Author(s):  
Sung In Hong ◽  
Joon Woo Park ◽  
Young Hee Jung ◽  
Ki Yong Ann
Keyword(s):  
Pore Structure ◽  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Cement Matrix ◽  
Network System ◽  
Air Voids ◽  
Mercury Intrusion ◽  
Entrapped Air ◽  
Entrained Air

In this study, a modified pore structure of cement based material with respect to a path for ingressive ions was established. Of pores in a concrete, gel pores and other entrapped air voids were excluded from modelling the pore structure as no interests are given due to the ions immobilization of cement paste media. To setup the pore structure, the linear traverse method (LTM) was used to distribute air voids along the traverse line in a hexahedron cement paste structure, followed by including entrained air voids to fill up the least space of the cement matrix and making a network of the air voids through capillary pores at the variation in the diameters. Then the mercury intrusion porosimetry (MIP) was used to iteratively approach an accordance rate with calculated one from the above way to get into appropriate convergence value. As a result, for the OPC specimen the developed model shows a somewhat relevant value of 42.4 % of the accordance rate compared to empirical one and 64.24 of the ratio of ionic path to original distance within a concrete.

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