Carbonation of slag concrete: Effect of the cement replacement level and curing on the carbonation coefficient – Effect of carbonation on the pore structure

2013 ◽  
Vol 35 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Elke Gruyaert ◽  
Philip Van den Heede ◽  
Nele De Belie
Keyword(s):  
Pore Structure ◽  
Replacement Level ◽  
Cement Replacement

Strength and Transport Properties of Concretes Modified with Coarse Limestone Powder to Compensate for Dilution Effects

2012 ◽  
Vol 2290 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Narayanan Neithalath ◽  
Hieu T. Cam
Keyword(s):  
Pore Structure ◽  
Silica Fume ◽  
Dilution Effect ◽  
Limestone Powder ◽  
Structure Parameter ◽  
Pore Structure Parameter ◽  
Replacement Level ◽  
Chloride Permeability ◽  
Cement Replacement ◽  
The Impact

The use of a coarse limestone powder (median particle size of approximately 70 μm, five times larger than cement particles) as a cement replacement material results in a dilution effect. The magnitude of strength and transport property reduction is found to be greater than the magnitude of the cement replacement level. In this paper, methodologies to proportion concrete containing 10% to 15% of coarse limestone powder, in which the dilution effect is compensated through a combination of reduction in water-to-powder ratio and addition of 5% of silica fume, are discussed. Limestone–silica fume blended concretes at a reduced water-to-powder ratio (0.37 or 0.34, depending on limestone replacement level) show similar or higher 56-day compressive strengths than does the benchmark plain concrete with a water-to-cement ratio of 0.40. The rapid chloride permeability and non–steady state migration values of the modified concretes are evaluated along with their pore structure parameter extracted from electrical impedance data. The impact of water-to-powder reduction and silica fume incorporation is quantified through this pore structure parameter.

Effect of Ground Granulated Blast Furnace Slag on Compressive Strength of POFA Blended Concrete

2015 ◽  
Vol 802 ◽  
pp. 142-148
Author(s):  
M.N. Noor Azline ◽  
Farah Nora Aznieta Abd Aziz ◽  
Arafa Suleiman Juma
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Strength Development ◽  
Replacement Level ◽  
Concrete Compressive Strength ◽  
Cement Replacement ◽  
Granulated Blast Furnace Slag ◽  
Strength Tests ◽  
Furnace Slag

The article reports a laboratory experimental programme that investigated effect of ground granulated blast furnace (GGBS) on compressive strength of POFA ternary concrete. Compressive strength tests were performed at a range of cements combinations, including 100%PC, two POFA levels for binary concrete, 35% and 45%, and 15%GGBS inclusion for POFA ternary concrete. The compressive strength results were examined in comparison to PC only and equivalent POFA binary concretes for up to 28 days. Results show that the reduction in compressive strength is greater with the higher cement replacement level for all concretes particularly for POFA binary concretes. However, 15%GGBS in POFA blended concrete has a comparable compressive strength compared to PC concrete at both, 35% and 45%, cement replacement levels except for ternary concrete at 0.65 w/c. In addition, the compressive strength of ternary concrete is slightly higher compared to binary concrete for all concrete combinations. Although there is no significant noticeable influence on strength development, the presence of GGBS did not adverse the strength development of POFA blended concrete. Thus, it can be concluded that GGBS compensates the adverse effect of POFA at early strength development.

scholarly journals Effect of Metakaolin on early Strength of GGBS Ternary Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1551-1557
Author(s):  
Noor Azline Mohd Nasir ◽  
M.J. McCarthy
Keyword(s):  
Adverse Effect ◽  
Portland Cement ◽  
Strength Development ◽  
Replacement Level ◽  
Cement Replacement ◽  
Experimental Programme ◽  
Early Strength

The article reports a laboratory experimental programme that investigated effect of metakaolin on the early strength of concrete made with ternary combinations of Portland cement (CEM I) with ground granulated blast slag (GGBS) and metakaolin (MK). The various level of cement combinations (65%CEM I+30%GGBS+5%MK, 45%CEM I+45%GGBS+10%MK and 45%CEM I+40%GGBS+15%MK) was examined in comparison to CEM I and equivalent GGBS binary concretes for up to 28 days. Results show that the reduction in early strength is greater with the higher cement replacement level. However, the ternary concrete containing 15%MK has minor increase in early strength compared to those with 10%MK but a significant increase in strength is examined at later age (28 days). It is concluded that the presence of MK compensates the adverse effect of GGBS at early strength development and improves the strength at later ages.

Effect of Fly Ash on Compressive Strength and Porosity of Self-Compacting Concrete

2015 ◽  
Vol 754-755 ◽  
pp. 447-451 ◽  
Author(s):  
Sunarmasto ◽  
Stefanus Adi Kristiawan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Replacement Level ◽  
Self Compacting Concrete ◽  
Cement Replacement ◽  
Vacuum Saturation ◽  
Saturation Method ◽  
Hardened Properties

Self-compacting concrete has been produced incorporating fly ash as cement replacement. The hardened properties of this concrete in term of compressive strength and porosity are investigated. The main goal of this investigation is to observe the effect of fly ash on those properties. The range of fly ash replacement level is 50%-70% by weight of the total binder. The compressive strength self-compacting concrete is reduced when fly ash replacement level is increased. The decrease in strength is more distinctive at 28 days of age compared to that of earlier or later age. Porosity as measured by vacuum saturation method tends to increase as fly ash replacement level is increased. A good correlation exists between porosity and compressive strength.

Properties of Mortar Incorporating Ground Dune Sand as Cement Replacement Material

2014 ◽  
Vol 925 ◽  
pp. 334-338
Author(s):  
Omer Abdalla Alawad ◽  
Abdulrahman Alhoziamy ◽  
Mohd Saleh Jaafar ◽  
Abdulaziz Al-Negheimish ◽  
Farah Noor Abdul Aziz
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Drying Shrinkage ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Replacement Level ◽  
Dune Sand ◽  
Cement Replacement ◽  
Autoclave Curing

Supplementary cementitious materials provide economic and environmental advantages in concrete industry. In this study, natural ground dune sand (GDS) was used as cement replacement material to fabricate mortar specimens. Ordinary Portland cement was replaced by GDS at five levels of replacement (0, 10, 20, 30, and 40 %) by weight. The cast mortar specimens were cured under normal and autoclave curing conditions. Compressive strength, drying shrinkage and resistance to sulfate attack were investigated. Results showed that the compressive strength under normal curing decreased as the level of replacement increased. However, under autoclave curing compressive strength increased as the content of GDS increased with 30% being the optimum replacement level. Autoclave curing decreased the drying shrinkage of plain and GDS blended mixtures by about 70% compared to control mixture cured under normal curing. Up to 270 days, no sulfate attack was observed on the GDS blended mixtures regardless of the replacement level. The use of GDS to reduce the Portland cement consumption can have a significant impact on the sustainability and economy of concrete construction.

Influence of Metashale as Cement Replacement on the Hygric Transport Properties of Concrete

2014 ◽  
Vol 1054 ◽  
pp. 188-193 ◽  
Author(s):  
Dana Koňáková ◽  
Veronika Hovorková ◽  
Eva Vejmelková ◽  
Martin Keppert ◽  
Robert Černý
Keyword(s):  
Transport Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Material ◽  
Raw Material ◽  
Replacement Level ◽  
Supplementary Cementitious Material ◽  
Cement Replacement ◽  
Concrete Properties ◽  
Clay Materials

This article is focused on the utilization of metashale as a supplementary cementitious material in concrete. Metashale as well as metakaolin is a product originating in the burning of clay materials, but in metashale production, the raw material is shale (aluminosilicates with granularity up to 0.02 mm). Four mixtures with cement replacement ranging from 0% up to 60% are designed and their properties are examined. Basic physical properties, mechanical strength, as well as hygric transport properties are measured and evaluated, in order to determine the influence of metashale on concrete properties. Experimental results show that for low amounts of cement replacement, metashale admixture leads to the improvement of studied material characteristics. When the material contains 40% of metashale, studied characteristics have almost similar values as the reference material. The worst values of measured properties are obtained for the replacement level of 60%. Nevertheless, all studied materials have appropriate properties to be applicable as high performance concrete.

Correlation of Pore Structure and Permeability by SEM-Image Analysis

1990 ◽  
Vol 48 (1) ◽  
pp. 428-429
Author(s):  
C. A. Callender ◽  
Wm. C. Dawson ◽  
J. J. Funk
Keyword(s):  
Image Analysis ◽  
Pore Structure ◽  
Imaging System ◽  
Pore Space ◽  
Simulation Models ◽  
Image Analyzer ◽  
Imaging Data ◽  
Sem Images ◽  
Thin Sections ◽  
Rock Types

The geometric structure of pore space in some carbonate rocks can be correlated with petrophysical measurements by quantitatively analyzing binaries generated from SEM images. Reservoirs with similar porosities can have markedly different permeabilities. Image analysis identifies which characteristics of a rock are responsible for the permeability differences. Imaging data can explain unusual fluid flow patterns which, in turn, can improve production simulation models.Analytical SchemeOur sample suite consists of 30 Middle East carbonates having porosities ranging from 21 to 28% and permeabilities from 92 to 2153 md. Engineering tests reveal the lack of a consistent (predictable) relationship between porosity and permeability (Fig. 1). Finely polished thin sections were studied petrographically to determine rock texture. The studied thin sections represent four petrographically distinct carbonate rock types ranging from compacted, poorly-sorted, dolomitized, intraclastic grainstones to well-sorted, foraminiferal,ooid, peloidal grainstones. The samples were analyzed for pore structure by a Tracor Northern 5500 IPP 5B/80 image analyzer and a 80386 microprocessor-based imaging system. Between 30 and 50 SEM-generated backscattered electron images (frames) were collected per thin section. Binaries were created from the gray level that represents the pore space. Calculated values were averaged and the data analyzed to determine which geological pore structure characteristics actually affect permeability.

Author response for "Effect of lithofacies on pore structure of the Cambrian organic‐rich shale in northern Guizhou, China"

2020 ◽  
Author(s):  
Peng Xia ◽  
Hongnan Li ◽  
Yong Fu ◽  
Wenlang Qiao ◽  
Chuan Guo ◽  
...  
Keyword(s):  
Pore Structure ◽  
Author Response
Sign in / Sign up

Export Citation Format

Share Document