scholarly journals Improving Frost Durability Prediction based on Relationship between Pore Structure and Water Absorption

2020 ◽  
Author(s):  
M. Aldabibi ◽  
M. Nokken ◽  
H. Ge
Keyword(s):  
Pore Structure ◽  
Water Absorption ◽  
Durability Prediction ◽  
Frost Durability

Synthesis of Polyvinyl Formal Sponge for Wound Care Dressing Application

2010 ◽  
Vol 152-153 ◽  
pp. 1650-1659
Author(s):  
Qing Hao Yang ◽  
Guang Xu Cheng ◽  
Zhi Cheng Zhang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Porous Structure ◽  
Pore Structure ◽  
Water Absorption ◽  
Wound Dressing ◽  
Wound Care ◽  
Acid Catalyst ◽  
The Other ◽  
Polyvinyl Formal

In an effort to seek poly(vinyl formal) (PVFM) foams based wound dressing pad material, a series of foamed PVFM materials have been synthesized under varied conditions. The influence of conditions on the properties of PVFM foam, such as mechanical properties, water absorption, pore structure and bulk density, is well discussed individually. It has been shown that both the reactant and acid catalyst affect the degree and speed of acetalization, therefore the mechanical properties, pores continuity and water absorption of the resultant sample. The addition of Na2CO3, surfactant and CMCNa are mainly influencing the porous structure as well as the mechanical properties and water absorption. One best sample with balanced properties is obtained. It possesses higher mechanical strength and water absorption while the other properties are similar, comparing with a commercial surgical PVFM sponge (YJ-1) currently used.

Modification of water absorption and pore structure of high-volume fly ash cement pastes by incorporating nanosilica

2021 ◽  
Vol 33 ◽  
pp. 101638 ◽  
Author(s):  
Qian Huang ◽  
Xiaohong Zhu ◽  
Dongsheng Liu ◽  
Liang Zhao ◽  
Min Zhao
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Water Absorption ◽  
High Volume ◽  
Cement Pastes ◽  
High Volume Fly Ash

scholarly journals Quantitative Analysis of Pore Structure on Frost Durability of Inorganic Building Materials

1991 ◽  
Vol 99 (1155) ◽  
pp. 1114-1119 ◽  
Author(s):  
Masahiko NAKAMURA ◽  
Takaaki OHNISHI ◽  
Masataka KAMITANI
Keyword(s):  
Quantitative Analysis ◽  
Pore Structure ◽  
Building Materials ◽  
Frost Durability

Porosity, pore structure and water absorption of polymer-modified mortars: An experimental study under different curing conditions

2013 ◽  
Vol 55 ◽  
pp. 221-233 ◽  
Author(s):  
Mahyuddin Ramli ◽  
Amin Akhavan Tabassi ◽  
Kwan Wai Hoe
Keyword(s):  
Experimental Study ◽  
Pore Structure ◽  
Water Absorption ◽  
Curing Conditions

scholarly journals The influence of type of cement on the degradation of microstructure and transport properties of cement mortars exposed to frost induced damage

2018 ◽  
Vol 174 ◽  
pp. 01014
Author(s):  
Alicja Wieczorek ◽  
Marcin Koniorczyk
Keyword(s):  
Absorption Coefficient ◽  
Pore Structure ◽  
Water Absorption ◽  
Transport Properties ◽  
Cement Mortar ◽  
Gas Permeability ◽  
Water Absorption Coefficient ◽  
Freeze Thaw ◽  
Cement Mortars ◽  
Small Pore

The purpose of the study is to understand how the cyclic water freezing (0, 25, 50, 75, 100 and 150 freeze-thaw cycles) impacts microstructure and transport properties of cement-based materials. Tests were conducted on cement mortars with different water/cement ratios (w/c=0.45 and 0.40) and on two types of cement (CEM I and CEM III) without air-entraining admixtures. The changes of pore size distribution and open porosity were investigated by means of mercury intrusion porosimetry. Additionally, the relationship between intrinsic permeability and the water absorption coefficient of cement mortar samples was analysed. The water absorption coefficient and gas permeability were determined using capillary absorption test and the modified RILEMCembureau method. The evolution of transport coefficients with growing number of freeze-thaw cycles were determined on the same sample. It was also established that change of pore structure (a decrease of small pore volume <100nm and increase of larger pores >100nm) induces an increase of water transport parameters such as permeability and water absorption coefficient. The higher gas permeability corresponds to the higher internal damage. In particular, it is associated with the change of cement mortar microstructure, which indicates damage of narrow channels in the pore structure of cement mortars.

scholarly journals Rock Pore Structure as Main Reason of Rock Deterioration

2014 ◽  
Vol 36 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Martin Ondrášik ◽  
Miloslav Kopecký
Keyword(s):  
Tensile Strength ◽  
Pore Structure ◽  
Water Absorption ◽  
Pore Water ◽  
Construction Material ◽  
Adsorbed Water ◽  
Rock Properties ◽  
Exclusion Criterion ◽  
Hydraulic Pressure ◽  
Freeze Thaw

Abstract Crashed or dimensional rocks have been used as natural construction material, decoration stone or as material for artistic sculptures. Especially old historical towns not only in Slovakia have had experiences with use of stones for construction purposes for centuries. The whole buildings were made from dimensional stone, like sandstone, limestone or rhyolite. Pavements were made especially from basalt, andesite, rhyolite or granite. Also the most common modern construction material - concrete includes large amounts of crashed rock, especially limestone, dolostone and andesite. However, rock as any other material if exposed to exogenous processes starts to deteriorate. Especially mechanical weathering can be very intensive if rock with unsuitable rock properties is used. For long it had been believed that repeated freezing and thawing in relation to high absorption is the main reason of the rock deterioration. In Slovakia for many years the high water absorption was set as exclusion criterion for use of rocks and stones in building industry. Only after 1989 the absorption was accepted as merely informational rock property and not exclusion. The reason of the change was not the understanding of the relationship between the porosity and rock deterioration, but more or less good experiences with some high porous rocks used in constructions exposed to severe weather conditions and proving a lack of relationship between rock freeze-thaw resistivity and water absorption. Results of the recent worldwide research suggest that understanding a resistivity of rocks against deterioration is hidden not in the absorption but in the structure of rock pores in relation to thermodynamic properties of pore water and tensile strength of rocks and rock minerals. Also this article presents some results of research on rock deterioration and pore structure performed on 88 rock samples. The results divide the rocks tested into two groups - group N in which the pore water does not freeze even when the temperature decreases to -20 ºC, and the second group F in which the pore water freezes. It has been found that the rocks from group N contain critical portion of adsorbed water in pores which prevents freezing of the pore water. The presence of adsorbed water enables thermodynamic processes related to osmosis which are dominantly responsible for deterioration of rocks from group N. A high correlation (R = 0.81) between content of adsorbed water and freeze-thaw loss was proved and can be used as durability estimator of rocks from group N. The rock deterioration of group F is caused not only by osmosis, but also by some other processes and influences, such as hydraulic pressure, permeability, grain size, rock and mineral tensile strength, degree of saturation, etc., and the deterioration cannot be predicted yet without the freeze-thaw test. Since the contents of absorbed water and ratio between adsorbed and bulk water (of which the absorbed water consists) is controlled by the porosity and pore structure, it can be concluded that the deterioration of some rocks is strongly related to rock pore structure.

Effects of pore structure and water absorption on internal curing efficiency of porous aggregates

2018 ◽  
Vol 163 ◽  
pp. 949-959 ◽  
Author(s):  
Dinghua Zou ◽  
Kun Li ◽  
Weidong Li ◽  
Haiyan Li ◽  
Tianlu Cao
Keyword(s):  
Pore Structure ◽  
Water Absorption ◽  
Internal Curing

scholarly journals Capillary Water Absorption and Micro Pore Connectivity of Concrete with Fractal Analysis

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 892
Author(s):  
Xiangqun Ding ◽  
Xinyu Liang ◽  
Yichao Zhang ◽  
Yanfeng Fang ◽  
Jinghai Zhou ◽  
...  
Keyword(s):  
Pore Structure ◽  
Water Absorption ◽  
Fractal Theory ◽  
Mineral Admixtures ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Connectivity Probability ◽  
Fractal Characteristics ◽  
Different Diameters ◽  
The Relationship

This study focuses on the relationship between the complexity of pore structure and capillary water absorption of concrete, as well as the connection behavior of concrete in specific directions. In this paper, the water absorption of concrete with different binders was tested during the curing process, and the pore structure of concrete was investigated by mercury intrusion porosimetry (MIP). The results show that the water absorption of concrete with mineral admixtures is lower, mainly due to the existence of reasonable pore structure. The effect of slag on concrete modification is more remarkable comparing with fly ash. In addition, the analysis shows that the pore with different diameters has different fractal characteristics. The connectivity probability and water absorption of unidirectional chaotic pore are linearly correlated with the pore diameter of 50–550 nm, and the correlation coefficient reaches a very significant level, and detailed analysis was undertaken to interpret these results based on fractal theory.

Pore structure, adsorption, and water absorption of expanded perlite mortar in external thermal insulation composite system during aging

2021 ◽  
Vol 116 ◽  
pp. 103900
Author(s):  
Houren Xiong ◽  
Kelong Yuan ◽  
Jinming Xu ◽  
Minjie Wen
Keyword(s):  
Pore Structure ◽  
Water Absorption ◽  
Thermal Insulation ◽  
Composite System ◽  
Expanded Perlite

Water absorption by coals: effects of pore structure and surface oxygen

Fuel ◽  
1986 ◽  
Vol 65 (2) ◽  
pp. 288-291 ◽  
Author(s):  
Ryuichi Kaji ◽  
Yasushi Muranaka ◽  
Keizo Otsuka ◽  
Yukio Hishinuma
Keyword(s):  
Pore Structure ◽  
Water Absorption ◽  
Surface Oxygen
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