The synergistic effect of AFt enhancement and expansion in Portland cement-aluminate cement-FGD gypsum composite cementitious system

2018 ◽  
Vol 190 ◽  
pp. 985-994 ◽  
Author(s):  
Yongjuan Zhang ◽  
Ping Yu ◽  
Fei Pan ◽  
Yan He
Keyword(s):  
Synergistic Effect ◽  
Portland Cement ◽  
Fgd Gypsum ◽  
Cementitious System ◽  
Aluminate Cement

scholarly journals Influence of Cementitious System Composition on the Retarding Effects of Borax and Zinc Oxide

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2340
Author(s):  
Feraidon F. Ataie
Keyword(s):  
Zinc Oxide ◽  
Portland Cement ◽  
Heat Of Hydration ◽  
Hydration Products ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
System Composition ◽  
Cementitious System ◽  
Cementitious Systems ◽  
Aluminate Cement

This research investigated the retarding impact of zinc oxide (ZnO) and borax (Na2[B4O5(OH)4]·8H2O) on hydration of Portland cement, calcium aluminate cement (CAC), and calcium sulfoaluminate cement (CSA). Heat of hydration of cement paste samples with and without ZnO and borax was used to measure the influence of ZnO and borax on the set time of these cementitious systems. It was found that both ZnO and borax can retard the set time of Portland cement systems; however, ZnO was shown to be a stronger set time retarder than borax for these systems. ZnO did not show any retarding impact on CAC and CSA systems while addition of borax in these systems prolonged the set time. It was concluded that ZnO does not poison the nucleation and/or growth of CSA and CAC hydration products. We suggest that borax retards the cement set time by suppressing the dissolution of cement phases.

scholarly journals Calorimetry in the studies of by-pass cement kiln dust as an additive to the calcium aluminate cement

2019 ◽  
Vol 138 (6) ◽  
pp. 4561-4569 ◽  
Author(s):  
Wiesława Nocuń-Wczelik ◽  
Katarzyna Stolarska
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Cement Kiln ◽  
Phase Assemblage ◽  
Chemical Shrinkage ◽  
High Calcium ◽  
Kinetics Of ◽  
Aluminate Cement

Abstract The studies focused on the kinetics of early hydration in the high-calcium aluminate cement (CAC 70)—by-pass cement kiln dusts (BPCKD)—mixtures. For this purpose, the mixtures of cement with this additive or with some potential constituents of dusts were produced. The microcalorimeter was applied to follow the kinetics of hydration. The investigations with the aim of finding the relationship between the components of initial mixtures and the modification of hydration process were carried out. The rheological properties were characterized, and the chemical shrinkage characteristics were produced. The phase assemblage characterization and microscopic observations were done as well. In case of the high-calcium aluminate-based binders, the modification of setting process was observed; the rheological properties and chemical shrinkage were affected too. The acceleration of heat evolution—the shortening of so-called induction period in the presence of BPCKD additive—was observed. The results were compared to those obtained for the CAC with ordinary Portland cement additive. The results of calorimetric measurements are discussed in terms of the chemical and phase assemblage of this additive as compared to the Portland cement clinker precursors and potassium chloride—the solid and liquid components of the dust.

Hydration of ternary cementitious system: Portland cement, fly ash and silica fume

2014 ◽  
Vol 119 (1) ◽  
pp. 381-389 ◽  
Author(s):  
N. B. Singh ◽  
Meenu Kalra ◽  
Mukesh Kumar ◽  
Sarita Rai
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Silica Fume ◽  
Cementitious System

scholarly journals Possibilities of using aluminate cements in high-rise construction

2018 ◽  
Vol 33 ◽  
pp. 02056
Author(s):  
Maria Kaddo
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Service Life ◽  
Portland Cement ◽  
Physical And Mechanical Properties ◽  
High Alumina ◽  
Corrosion Resistant ◽  
High Rise ◽  
Aluminate Cement

The article describes preferable ways of usage of alternative binders for high-rise construction based on aluminate cements. Possible areas of rational use of aluminate cements with the purpose of increasing the service life of materials and the adequacy of the durability of materials with the required durability of the building are analyzed. The results of the structure, shrinkage and physical and mechanical properties of concrete obtained from dry mixes on the base of aluminate cements for self-leveling floors are presented. To study the shrinkage mechanism of curing binders and to evaluate the role of evaporation of water in the development of shrinkage was undertaken experiment with simple unfilled systems: gypsum binder, portland cement and «corrosion resistant high alumina cement + gypsum». Principle possibility of binder with compensated shrinkage based on aluminate cement, gypsum and modern superplasticizers was defined, as well as cracking resistance and corrosion resistance provide durability of the composition.

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