Influence Of Curing On Surface Characteristics Of Concrete

1988 ◽  
Vol 137 ◽  
Author(s):  
M. Sadegzadeh ◽  
R. J. Kettle ◽  
C. L. Page
Keyword(s):  
Abrasion Resistance ◽  
Mercury Intrusion Porosimetry ◽  
Total Pore Volume ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Cement Matrix ◽  
Mercury Intrusion ◽  
Rolling Wheel ◽  
Curing Regime ◽  
Curing Regimes

AbstractAn experimental assessment is presented of the influence of curing regimes on the abrasion resistance of concrete. Specimens have been produced from several different mix compositions and the abrasion resistance has been measured using a rolling-wheel apparatus. To explore these relationships, microstructural features of the cement matrix components of the surface have been studied by mercury intrusion porosimetry. The results indicate the abrasion resistance of concrete is controlled by the pore structure of the surface matrix. The nature of the curing regime having significantly influenced the pore size distribution and total pore volume of the surface matrix of the concrete surface.

scholarly journals Study on the Pore Structure Characteristics of Ferronickel-Slag-Mixed Ternary-Blended Cement

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4863
Author(s):  
Won Jung Cho ◽  
Min Jae Kim ◽  
Ji Seok Kim
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Pore Structure ◽  
Mercury Intrusion Porosimetry ◽  
Chloride Transport ◽  
Blended Cement ◽  
Cement Matrix ◽  
X Ray ◽  
Mercury Intrusion ◽  
Ferronickel Slag

Pore structure development in Portland cement, fly ash, or/and ferronickel slag (FNS) was investigated using mercury intrusion porosimetry and X-ray CT tomography. The progress of hydration was observed using X-ray diffraction (XRD) analysis and compressive strength while durability of concrete was monitored by chloride penetration resistance and chloride profiles. Mercury intrusion porosimetry (MIP) results suggested that the blended cement had a higher porosity while lower critical pore size. The major reason to this increased porosity was the formation of meso and micro pores compared to ordinary Portland cement (OPC). In terms of chloride transport, replaced cement, especially ternary-blended cement had higher resistance to chloride transport and exhibited slightly lower development of compressive strength. X-ray CT tomography shows that the influence of pore structure of ternary-blended cement on the ionic transport was strongly related to the pore connectivity of cement matrix.

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.

scholarly journals An Experimental Study on Concrete’s Durability and Mechanical Characteristics Subjected to Different Curing Regimes

2021 ◽  
Vol 7 (4) ◽  
pp. 676-689
Author(s):  
Edgar L. S. Borrero ◽  
Visar Farhangi ◽  
Kazem Jadidi ◽  
Moses Karakouzian
Keyword(s):  
Compressive Strength ◽  
Chloride Ion ◽  
Concrete Surface ◽  
Surface Resistivity ◽  
Curing Conditions ◽  
Chloride Ion Penetration ◽  
Curing Regime ◽  
Curing Regimes ◽  
Non Destructive ◽  
Ion Penetration

 Considering a constant demand in construction of concrete structures to develop novel approaches for predicting the concert’s properties, a host of investigations were performed on concrete’s mechanical properties and durability under various curing regimes. However, few studies were concerned with evaluating the concrete’s durability using non-destructive concrete surface resistivity tests by applying various curing conditions. The present study compares the influence of different curing regimes on durability and compressive strength of concrete to recommend the most effective curing conditions on concrete’s characteristics.  Five curing conditions including ambient, laboratory, dry oven, wet oven and 7-days were analyzed. Accordingly, a non-destructive concrete surface resistivity test was performed on the concrete specimens using hand-held Wenner Resipod probe meter as a reliable and rapid approach. To analyze specimen’s durability, results of the surface sensitivity tests were correlated to chloride ion penetration rate based on the cylinder specimen dimensions and the degree of chloride ion penetration. The compressive strength tests were conducted on the specimens after 7, 28 and 56 days to determine the effect of curing conditions at different ages. Based on the reported outcomes, applying the wet oven curing regime results in higher compressive strength and durability compared to the other curing conditions. Doi: 10.28991/cej-2021-03091681 Full Text: PDF

scholarly journals Effect of Hydrogen Nanobubbles on the Mechanical Strength and Watertightness of Cement Mixtures

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1823
Author(s):  
Won-Kyung Kim ◽  
Young-Ho Kim ◽  
Gigwon Hong ◽  
Jong-Min Kim ◽  
Jung-Geun Han ◽  
...  
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Cement Mortar ◽  
Stable State ◽  
Pozzolanic Reaction ◽  
Hydration Reaction ◽  
High Concentration ◽  
Mercury Intrusion ◽  
Electron Microscope Analysis ◽  
Mixing Water ◽  
Cement Mixtures

This study analyzed the effects of applying highly concentrated hydrogen nanobubble water (HNBW) on the workability, durability, watertightness, and microstructure of cement mixtures. The number of hydrogen nanobubbles was concentrated twofold to a more stable state using osmosis. The compressive strength of the cement mortar for each curing day was improved by about 3.7–15.79%, compared to the specimen that used general water, when two concentrations of HNBW were used as the mixing water. The results of mercury intrusion porosimetry and a scanning electron microscope analysis of the cement paste showed that the pore volume of the specimen decreased by about 4.38–10.26%, thereby improving the watertightness when high-concentration HNBW was used. The improvement in strength and watertightness is a result of the reduction of the microbubbles’ particle size, and the increase in the zeta potential and surface tension, which activated the hydration reaction of the cement and accelerated the pozzolanic reaction.

scholarly journals Nanoscale Pore Structure Characterization and Permeability of Mudrocks and Fine-Grained Sandstones in Coal Reservoirs by Scanning Electron Microscopy, Mercury Intrusion Porosimetry, and Low-Field Nuclear Magnetic Resonance

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Na Zhang ◽  
Fangfang Zhao ◽  
Pingye Guo ◽  
Jiabin Li ◽  
Weili Gong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Pore Size ◽  
Mercury Intrusion Porosimetry ◽  
Mercury Intrusion ◽  
Rock Samples ◽  
Fine Grained ◽  
Low Field ◽  
Water Saturated ◽  
Pore Types ◽  
Scanning Electron

Porosity and permeability of two typical sedimentary rocks in coal bearing strata of underground coal mines in China, i.e., mudrocks and fine-grained sandstones, were comprehensively investigated by multiple experimental methods. Measured porosity averages of the helium gas porosity (φg), MIP porosity (φMIP), water porosity (φw), and NMR porosity (φNMR) of the twelve investigated rock samples range from 1.78 to 16.50% and the measured gas permeabilities (Kg) range from 0.0003 to 2.4133 mD. Meanwhile, pore types, pore morphologies, and pore size distributions (PSD) were determined by focused ion beam scanning electron microscopy (FIB-SEM), mercury intrusion porosimetry (MIP), and low-field nuclear magnetic resonance (NMR). FIB-SEM image analyses showed that the mineral matrix pores including interparticle (interP) and intraparticle (intraP) pores with varied morphologies are the dominant pore types of the investigated rock samples while very few organic matter (OM) pores were observed. Results of the MIP and the full water-saturated NMR measurements showed that the PSD curves of the mudrock samples mostly present a unimodal pattern and nanopores with pore diameter less than 0.1 μm are their predominant pore type, while the PSD curves of the fine-grained sandstone samples are featured by a bimodal distribution. Furthermore, comparison of the full water-saturated and irreducible-water-saturated NMR measurements indicated that pores in the mudrocks are solely adsorption pores (normally pore size < 0.1 μm) whereas apart from a fraction of adsorption pores, a large part of the pores in the sandstone sample with relatively high porosity are seepage pores (normally pore size > 0.1 μm). Moreover, the PSD curves of NMR quantitatively converted from the NMR T2 spectra by T2Pc and weighted arithmetic mean (WAM) methods are in good agreement with the PSD curves of MIP. Finally, the applicability of three classic permeability estimation models based on MIP and NMR data to the investigated rock samples was evaluated.

scholarly journals Effects of Anti-Graffiti Protection on Concrete Durability

2014 ◽  
Vol 634 ◽  
pp. 517-526 ◽  
Author(s):  
Elsa Neto ◽  
Ana Souto ◽  
Aires Camões ◽  
Arlindo Begonha ◽  
Paulo Cachim
Keyword(s):  
Water Absorption ◽  
Atmospheric Pressure ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Experimental Program ◽  
Concrete Durability ◽  
Protection Systems ◽  
Before And After ◽  
Paint Removal ◽  
Durability Of Concrete

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.

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