Role of Blended Cements and Slag Cement to Improve Sustainability of Geotechnical Projects

IFCEE 2018 ◽  
2018 ◽  
Author(s):  
Charles M. Wilk ◽  
Gordon R. McLellan
Keyword(s):  
Slag Cement ◽  
Blended Cements

scholarly journals Sustainable low-carbon binders and concretes

2020 ◽  
Vol 166 ◽  
pp. 06007
Author(s):  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska ◽  
Stanislav Fic ◽  
Hanna Ivashchyshyn
Keyword(s):  
Activity Index ◽  
Chemical Properties ◽  
High Volume ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Cement Matrix ◽  
Low Carbon ◽  
Blended Cements ◽  
Physical And Chemical

Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.

Study on CaSO3 and CaO as Additives of Slag Cement

2013 ◽  
Vol 634-638 ◽  
pp. 297-301
Author(s):  
Guo Zhuo Gong ◽  
Shu Feng Ye ◽  
Jin Hong Li ◽  
Wen Fen Yang ◽  
Qiang Xie
Keyword(s):  
Flue Gas ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Cement Clinker ◽  
Slag Cement ◽  
Retarding Effect ◽  
Desulfurization Process ◽  
Main Components ◽  
Furnace Slag

CaSO3and CaO are main components in solid waste from flue gas semi-dry desulfurization process. A series of slag cements were prepared from cement clinker and blast furnace slag, in the process of which CaSO3 and CaO were added. The composition and macrostructure of the derived cements were studied in detail with the aid of XRD and SEM. Furthermore, the influence of amount of CaSO3and CaO on the mechanical properties and setting time for slag cement were evaluated, the mechanisms of which were also discussed. The results show that due to the formation of AFt and AFm in the hydration process, the CaSO3has an obvious setting retarding effect on the slag cement, and quality slag cement can be obtained when the amount of slag and CaSO3are 20% and 2%, respectively, the compressive strengths of which at 3, 7, 28 d are 30.8, 39.1, 53.7 MPa, and bending strengths at 3, 7, 28 d are 9.6, 10, 11.9MPa, respectively. Besides, CaO added which can play a role of alkali-activator for slag cement can not cause the soundness problem of slag cement.

Hydration Reactions in Cement Pastes Incorporating Fly Ash and Other Pozzolanic Materials

1986 ◽  
Vol 86 ◽  
Author(s):  
F. P. Glasser ◽  
S. Diamond ◽  
D. M. Roy
Keyword(s):  
Fly Ash ◽  
Physical Properties ◽  
Silica Content ◽  
Cement Pastes ◽  
Blended Cements ◽  
Natural Pozzolans ◽  
High Calcium ◽  
High Silica ◽  
Class F Fly Ash

ABSTRACTA model for reactions that occur in hydrating portland cement is now generally well developed. Incorporation of various by-products to form blended cements modifies both the hydration reactions and the physical properties of the resulting pastes. A review of recent progress in understanding the effects of blending agents on these reactions is presented. The blending agents considered are low-calcium (Class F) fly ash, high calcium (Class C) fly ash, blast furnace slag, silica fume, biosilica and natural pozzolans. Effects of the blending agents on physical properties such as rheology are also considered. Particular attention is given to the essential role of alkalies in pore solutions and the beneficial reactions that occur with high silica content blending agents.

scholarly journals Pozzolanic Activity of Zeolites: The Role of Si/Al Ratio

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4231 ◽  
Author(s):  
Barbara Liguori ◽  
Paolo Aprea ◽  
Bruno de Gennaro ◽  
Fabio Iucolano ◽  
Abner Colella ◽  
...  
Keyword(s):  
Point Of View ◽  
Pozzolanic Activity ◽  
X Ray Diffraction ◽  
Zeolite X ◽  
X Ray ◽  
Blended Cements ◽  
Natural Pozzolans ◽  
Synthetic Zeolites ◽  
Simple Systems

A great challenge of research is the utilization of natural or synthetic zeolites, in place of natural pozzolans, for manufacturing blended cements. The difficulties of interpretation of the pozzolanic behavior of natural zeolite-rich materials and the role played by their nature and composition can be overcome by studying more simple systems, such as pure synthetic zeolites. This study aims at investigating the pozzolanic ability of isostructural zeolites with different framework compositions, such as three sodium zeolites of the faujasite (FAU) framework type: LSX, X, and Y. The pozzolanic activity has been estimated by thermogravimetry and X-ray diffraction analysis. The overall outcome of the investigation is that the zeolite structure affects its pozzolanic activity, as zeolites with similar framework densities exhibit distinct abilities to fix lime. Moreover, the framework composition is effective either from a kinetic point of view or on the total amount of fixed lime. Zeolite X appears to possess the best average features.

From composition to the microstructure and durability of limestone ternary blended cements: A Systematic review

2021 ◽  
pp. 1-44
Author(s):  
Samuel Adu-Amankwah ◽  
Suraj Rahmon ◽  
Leon Black
Keyword(s):  
Large Scale ◽  
Air Entrainment ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Chloride Ingress ◽  
Blended Cements ◽  
Freeze Thaw ◽  
Significant Research ◽  
Large Scale Field

Limestone ternary cements have attracted significant research and commercial attention recently, for technical and environmental reasons. Standardization of these cements is imminent under BS EN197-5. Presently, detailed understanding of the hydration and microstructure evolution of limestone ternary cements from different alumina-rich supplementary cementitious materials (SCMs) exists in the scientific literature; improved reaction kinetics and additional phase assemblages refine the pore structure. However, understanding of the performance of these cements under exposure conditions is less prevalent. In this contribution, we review these data in a way that allows stakeholders to appreciate the capabilities of the different compositions and their performance. We focus our discussion on critically examining the interplay between the cement composition and the microstructure on durability. It is demonstrated that limestone ternary cements offer a pathway for reducing the embodied CO2 of concrete without compromising their performance. The resistance to chloride ingress, sulphate attack and ASR are significantly improved in a manner similar to binary cements. Carbonation and freeze-thaw resistance is generally lower than OPC but adequate air entrainment can offer improvement in freeze-thaw resistance. The challenge to widespread adoption of these cements is evidence of durability under field conditions. To this end, we recommend large-scale field trialling of these cements and understanding of the role of combined exposures on durability and mechanical properties.

Unlocking the role of MgO in the carbonation of alkali-activated slag cement

2018 ◽  
Vol 5 (7) ◽  
pp. 1661-1670 ◽  
Author(s):  
S. M. Park ◽  
J. G. Jang ◽  
H. K. Lee
Keyword(s):  
Slag Cement ◽  
Alkali Activated Slag ◽  
Activated Slag ◽  
Alkali Activated

MgO incorporation into alkali-activated slag cement reduces the rate of carbonation.

Role of chloride ions on expansion and strength reduction in plain and blended cements in sulfate environments

1995 ◽  
Vol 9 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Omar Saeed Baghabra Al-Amoudi ◽  
Mohammed Maslehuddin ◽  
Yaser A.B. Abdul-Al
Keyword(s):  
Chloride Ions ◽  
Strength Reduction ◽  
Blended Cements

Hydration Reactions in Cement Pastes Incorporating Fly Ash and Other Pozzolanic Materials

1986 ◽  
Vol 85 ◽  
Author(s):  
F. P. Glasser ◽  
S. Diamond ◽  
D. M. Roy
Keyword(s):  
Fly Ash ◽  
Physical Properties ◽  
Silica Content ◽  
Cement Pastes ◽  
Blended Cements ◽  
Natural Pozzolans ◽  
High Calcium ◽  
High Silica ◽  
Class F Fly Ash

ABSTRACTA model for reactions that occur in hydrating portland cement is now generally well developed. Incorporation of various by-products to form blended cements modifies both the hydration reactions and the physical properties of the resulting pastes. A review of recent progress in understanding the effects of blending agents on these reactions is presented. The blending agents considered are low-calcium (Class F) fly ash, high calcium (Class C) fly ash, blast furnace slag, silica fume, biosilica and natural pozzolans. Effects of the blending agents on physical properties such as rheology are also considered. Particular attention is given to the essential role of alkalies in pore solutions and the beneficial reactions that occur with high silica content blending agents.

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