The Pore Structure of Phosphoaluminate Cement
The effects of curing time and water-to-cement ratio (W/C) on the pore structure of phosphoaluminate cement (PAC) paste are here presented. Based on the adsorption and condensation theory the adsorption isotherm of hardened paste was tested using the Brunauer-Emmett-Teller (BET) nitrogen adsorption method. The phase composition and morphology of hydration products cured at different
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Effects of bentonite on pore structure and permeability of
Nov 10 2019 · The pore structure and permeability of cement-based materials have great influence on the durability of application of this materials. The effects of bentonite on the pore structure and permeability of cement mortar were investigated in this paper. Bentonite as a swelling potential clay was added to mortar at content 0 4 and 8 by weight of
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The influence of surface treatment on the transport
Nov 01 2020 · The pore structure of materials plays an important role in the permeability of the materials. Many characteristic pore size parameters such as total pore volume threshold and critical pore diameter and medium pore diameter have been correlated to the water permeability 37 38 .
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Multiple characterization study on porosity and pore
Dec 01 2015 · However this is a challenging task because once hardened calcium phosphate cements present an intricate morphology consisting of a network of precipitated crystals which generate a high intrinsic micro/nano porosity with pore sizes covering six orders of magnitude.
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(PDF) OMAE MODELING PORE CONTINUITY AND
The pore continuity analysis shows decisive in terms of damage of the sealing of the wellbore the relevance to control of the capillary pore structure inside an cement and to control its integrity. evolving microstructure in relation to its permeability and it In this paper emphasis will be on the leakage of CO2-rich ease to leak gaseous
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Realistic pore structure of Portland cement paste
In this study the pore structure of Portland cement paste is experimentally characterized by MIP (mercury intrusion porosimetry) and nitrogen adsorption and simulated by a newly developed status-oriented computer model. Cement pastes with w/c=0.3 0.4 and 0.5 at ages from 1 day to 120 days are comprehensively investigated. It is found that MIP cannot generate valid pore size distribution
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Relation between pore size distribution permeability and
Relationships between saturated permeability and pore structure parameters as determined by drying at 105 degree C and mercury intrusion porosimetry are presented for hardened cement pastes of
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Pore structure and permeability of hardened calcium
Dec 07 2012 · The conversion of hydrated calcium aluminate cement (CAC) leads to an increase of its porosity which results in lower strength and higher permeability. Due to particular failures in the past caused by conversion of CAC concretes their use is sometimes considered to be not reliable. To evaluate the durability of converted CAC pastes of two CACs were prepared at low w/c ratios (0.25
Get PriceCONCRETE MICROSTRUCTURE POROSITY AND
from the viewpoint of permeabillty-pore structure or fracture mechanics-pore structure relationships the majority of porosity in this range is not important. With respect to permeability it is well recognized that only pores having diameters greater than some value significantly contribute to permeability.
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Frontiers Factors Affecting Permeability Reduction of
Jul 21 2020 · Table 2 indicated that the permeability coefficients of single fracture rocks after MICP grouting ranged from 0.3040 10 –4 m/s to 0.4693 10 –4 m/s and the ones before MICP grouting from 0.1536 m/s to 0.4342 m/s. The permeability reduction of
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Pore structure and permeability of hardened calcium
Request PDF Pore structure and permeability of hardened calcium aluminate cement pastes of low w/c ratio The conversion of hydrated calcium aluminate cement (CAC) leads to an increase of its
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2 Pore structure and transport processes Concrete durability
This is applicable to all three transport processes. 2.7 Influence of pore structure and transport processes on the durability of concrete The overall effect of pore structure and permeability influencing the penetration of various aggressive substances and thereby their effect on the durability of concrete can be visualised in Fig. 2.4.26
Get PriceRealistic pore structure of Portland cement paste
In this study the pore structure of Portland cement paste is experimentally characterized by MIP (mercury intrusion porosimetry) and nitrogen adsorption and simulated by a newly developed status-oriented computer model. Cement pastes with w/c=0.3 0.4 and 0.5 at ages from 1 day to 120 days are comprehensively investigated. It is found that MIP cannot generate valid pore size distribution
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Mechanical properties and permeability of red mud-blast
Red mud a by-product of alumina production has a great impact on the environment due to its high alkalinity. In this paper two-part geopolymer mortar was synthesized by combining red mud and blast furnace slag (BFS) to obtain optimized compressive strength and flexural strength for construction materials. Geopolymer concrete was prepared with the cementitious material in the concrete
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Pore structure and permeability of hardened cement paste
May 25 2015 · Pore structure and permeability of hardened cement paste Open PDF. Magazine of Concrete Research. ISSN E-ISSN X. Volume 37 Issue 133 December 1985 pp. . Prev Next > Pore structure and permeability of hardened cement paste Authors D. C. Hughes BSc PhD
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Modification of CO2 capture and pore structure of hardened
For each curing temperature the effect of TiO2 on (i) compressive and flexural strength at 7 days (ii) calcium hydroxide (CH) formation at 1 3 at 7 days and (iii) pore structure have been studied.
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Mitochondrial permeability transition poreWikipedia
The mitochondrial permeability transition pore (mPTP or MPTP also referred to as PTP mTP or MTP) is a protein that is formed in the inner membrane of the mitochondria under certain pathological conditions such as traumatic brain injury and stroke.Opening allows increase in the permeability of the mitochondrial membranes to molecules of less than 1500 Daltons in molecular weight.
Get PriceFluid Permeability of Ground Steel Slag-Blended Composites
The resource utilization of steel slag has attracted wide attention. In the present work the pore structure of cement paste with and without ground basic oxygen furnace slag (BOFS) up to 180 days was investigated by mercury intrusion porosimetry. Permeability was evaluated from the tested pore structure. Results indicate that the porosity critical pore radius pore-throat radius and
Get PricePhysiological and pathological roles of the mitochondrial
Prolonged mitochondrial permeability transition pore (MPTP) opening results in mitochondrial energetic dysfunction organelle swelling rupture and typically a type of necrotic cell death. However acute opening of the MPTP has a critical physiologic role in regulating mitochondrial Ca(2 ) handling
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Delft University of Technology Effect of admixture on the
101 minerals) at which the porosity is reduced. This leads to the shift of pore size of hardened AAM 102 towards smaller ranges which improves the material performance by for instance a higher 103 material strength reduced permeability and enhanced ion diffusion resistance (e.g. chloride).
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Mechanical Characteristics of Hardened Concrete with
Khatib and Wild presented the results of pore structure of the cement pastes in which 5 10 and 15 cement content were replaced by MK however water binder ratio of 0.55 was kept constant. Results of pore structure of the pastes cured for 3 to 365 days were examined through mercury intrusion porosimetry (MIP).
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Durability and Permeability of Concrete
4. Permeability • Permeability is defined as the property that governs the rate of flow of a fluid into a porous solid. 5. Durability of Concrete • Durability of concrete ability to resist weathering action chemical attack abrasion or any process of deterioration. 6.
Get PriceThe Pore Structure of Phosphoaluminate Cement
The effects of curing time and water-to-cement ratio (W/C) on the pore structure of phosphoaluminate cement (PAC) paste are here presented. Based on the adsorption and condensation theory the adsorption isotherm of hardened paste was tested using the Brunauer-Emmett-Teller (BET) nitrogen adsorption method. The phase composition and morphology of hydration products cured at different
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Structure of ATPase the world s smallest turbine solved
Sep 14 2020 · This newly uncovered structure sheds light on a controversy in biology how and where the so-called permeability transition pore opens. This pore
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Effect of natural pozzolans on porosity and pore
Even though it has been demonstrated that the pozzolanic reaction of natural pozzolans produce more calcium silicate hydrates and create a more refined pore structure this is not reflected in
Get PriceCharacterizing the Pore Structure of Carbonated Natural
This paper focuses on examining the pore structure of a cementitious paste made with a calcium silicate (wollastonite) that reacts with carbon dioxide and water to form a hardened solid. The pore structure of the hardened solid has been characterized using vapor sorption and desorption low-temperature differential scanning calorimetry (LT-DSC) and scanning electron microscopy (SEM).
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Mechanical properties and permeability of red mud-blast
Red mud a by-product of alumina production has a great impact on the environment due to its high alkalinity. In this paper two-part geopolymer mortar was synthesized by combining red mud and blast furnace slag (BFS) to obtain optimized compressive strength and flexural strength for construction materials. Geopolymer concrete was prepared with the cementitious material in the concrete
Get Price
Effect of natural pozzolans on porosity and pore
Even though it has been demonstrated that the pozzolanic reaction of natural pozzolans produce more calcium silicate hydrates and create a more refined pore structure this is not reflected in
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Relationships between permeability and pore structure of
Relationships between saturated permeability and pore structure parameters as determined by drying at 105°C and mercury intrusion porosimetry are presented for hardened cement pastes of differing water/cement ratios and times of hydration.
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