scholarly journals Effects of combination of retarders on calcium sulfoaluminate (CSA) cement systems

2020 ◽  
Author(s):  
Cansu Acarturk ◽  
Lisa Burris
Keyword(s):  
Citric Acid ◽  
Tartaric Acid ◽  
Carbon Dioxide Emissions ◽  
Setting Time ◽  
Field Performance ◽  
Calcium Content ◽  
Calcium Sulfoaluminate ◽  
Rapid Setting ◽  
Phase Development ◽  
Short Working

One method of increasing the sustainability of concrete construction through reductions in emissions and energy requirements is through the use of alternative binders. Calcium Sulfoaluminate (CSA) cement has been developed as a low energy cement, as it has up to 40% less embodied carbon dioxide emissions due to its lower calcium content and reduced clinkering temperature relative to Portland cement. However, despite the advantages of CSA cement, its rapid setting time limits the use of this material to applications when short working time is required. To facilitate better control of the timing of CSA hardening and strength gain, several approaches to retarder usage and dosing have been studied. In this paper, use of chemical retardants, including citric acid, tartaric acid, and borax with CSA cement used alone and in combination with each other, and their effects on phase development and hardened binder properties were evaluated and discussed in relation to their retardation mechanisms. Because of differing working mechanisms of the retarders, combinations of citric acid and borax showed relationships that averaged the properties of each retarder, while combinations of citric acid and tartaric acid showed relationships that added the effects of the two retarders together. Setting time of CSA cement was delayed successfully, using retarders both alone and in combination, however combination mixes generally decreased compressive strength compared to the strengths of equivalent total singular retarder dosage. Relationships between heat release and setting time were developed and may prove useful for prediction of largescale application field performance.

scholarly journals Effect of Tartaric Acid on the Printable, Rheological and Mechanical Properties of 3D Printing Sulphoaluminate Cement Paste

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2417 ◽  
Author(s):  
Mingxu Chen ◽  
Xiangyang Guo ◽  
Yan Zheng ◽  
Laibo Li ◽  
Zhen Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
3D Printing ◽  
Tartaric Acid ◽  
Apparent Viscosity ◽  
Setting Time ◽  
Sulphoaluminate Cement ◽  
Low Viscosity ◽  
Ultimate Deformation ◽  
Rapid Setting

Rapid setting and low viscosity of sulphoaluminate cement (SAC) make it difficult to be extruded by 3D printing (3DP) technique. In this study, the effect of tartaric acid (TA) on printability, rheology and mechanical property of 3DP SAC paste is investigated. The experimental results indicate that the setting time, hydration evolution and apparent viscosity of SAC paste can be well controlled by adding a proper amount of TA to satisfy the requirements of 3DP. An excellent structure of SAC paste with the ultimate deformation rate less than 10% can be printed without compromising mechanical strength.

Effect of Anhydrite on the Early Hydration Performance of Rapid Setting and Hardening Belite Sulfoaluminate Cement

2017 ◽  
Vol 898 ◽  
pp. 1990-1995 ◽  
Author(s):  
Ming Zhang Lan ◽  
Bin Feng Xiang ◽  
Jian Feng Wang ◽  
Xu Dong Zhao ◽  
Xiao Ying Wang
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
High Strength ◽  
Cement Clinker ◽  
Hydration Kinetics ◽  
Early Hydration ◽  
Free Lime ◽  
Calcium Sulfoaluminate ◽  
Setting Times ◽  
Rapid Setting

In order to investigate the early hydration behavior of rapid setting and hardening belite sulfoaluminate cements, the methods of X-ray Diffraction, Scanning Electron Microscope, Compressive Strength test and Setting Times test were used to identify and quantify the hydration kinetics and microstructure of this new-found cements in China. The results showed that the main mineral compositions of high belite sulfoaluminate cement clinker included calcium sulfoaluminate (4CaO·3Al2O3·CaSO4), belite (2CaO·SiO2), ferrite phase, free gypsum and free lime. It was found that not only the setting time and compressive strength but also the composition of hydration products were influenced by anhydrite to some extent. Meanwhile, a mass of AFt and AFm generated along with the hydration process at different ages, overlapped, crossed and penetrated through calcium silicate hydrate gel and aluminum oxide to form a relatively dense structure which could contribute to the high strength of cement.

scholarly journals Effect of Flue Gas Desulfurization Gypsum on the Properties of Calcium Sulfoaluminate Cement Blended with Ground Granulated Blast Furnace Slag

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 382 ◽  
Author(s):  
Danying Gao ◽  
Zhenqing Zhang ◽  
Yang Meng ◽  
Jiyu Tang ◽  
Lin Yang
Keyword(s):  
Blast Furnace ◽  
Mechanical Strength ◽  
Flue Gas ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Flue Gas Desulfurization ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This work aims to investigate the effect of additional flue gas desulfurization gypsum (FGDG) on the properties of calcium sulfoaluminate cement (CSAC) blended with ground granulated blast furnace slag (GGBFS). The hydration rate, setting time, mechanical strength, pore structure and hydration products of the CSAC-GGBFS mixture containing FGDG were investigated systematically. The results show that the addition of FGDG promotes the hydration of the CSAC-GGBFS mixture and improves its mechanical strength; however, the FGDG content should not exceed 6%.

scholarly journals Printability and Setting Time of CSA Cement with Na2SiO3 and Gypsum for Binder Jetting 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2811
Author(s):  
Okpin Na ◽  
Kangmin Kim ◽  
Hyunjoo Lee ◽  
Hyunseung Lee
Keyword(s):  
3D Printing ◽  
Sodium Silicate ◽  
Setting Time ◽  
Sodium Silicate Solution ◽  
Preliminary Test ◽  
Silicate Solution ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Parametric Studies ◽  
Binder Jetting

The purpose of this study is to optimize the composition of CSA (calcium sulfoaluminate) cement with sodium silicate (Na2SiO3) and gypsum for binder jetting 3D printing. The preliminary test was carried out with an applicator to decide the proper thickness of one layer before using the 3D printer. A liquid binder was then selected to maintain the shape of the particles. Based on the results, the optimal mixture of dry materials and a liquid activator was derived through various parametric studies. For dry materials, the optimum composition of CSA cement, gypsum, and sand was suggested, and the liquid activator made with sodium silicate solution and VMA (viscosity modified agent) were selected. The setting time with gypsum and sodium silicate was controlled within 30 s. In case of the delayed setting time and the rapid setting mixture, the jetting line was printed thicker or thinner and the accuracy of the printout was degraded. In order to adjust the viscosity of the liquid activator, 10% of the VMA was used in 35% of sodium silicate solution and the viscosity of 200–400 cP was suitable to be sprayed from the nozzle. With this optimal mixture, a prototype of atypical decorative wall was printed, and the compressive strength was measured at about 7 MPa.

scholarly journals Taste Interactions between Sweetness of Sucrose and Sourness of Citric and Tartaric Acid among Chinese and Danish Consumers

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1425
Author(s):  
Jonas Yde Junge ◽  
Anne Sjoerup Bertelsen ◽  
Line Ahm Mielby ◽  
Yan Zeng ◽  
Yuan-Xia Sun ◽  
...  
Keyword(s):  
Citric Acid ◽  
Tartaric Acid ◽  
Hierarchical Cluster ◽  
Taste Perception ◽  
Aqueous Samples ◽  
Chinese Consumers ◽  
Consumer Study ◽  
Agglomerative Hierarchical Cluster Analysis ◽  
Significant Difference ◽  
Sweetness Intensity

Tastes interact in almost every consumed food or beverage, yet many aspects of interactions, such as sweet-sour interactions, are not well understood. This study investigated the interaction between sweetness from sucrose and sourness from citric and tartaric acid, respectively. A cross-cultural consumer study was conducted in China (n = 120) and Denmark (n = 139), respectively. Participants evaluated six aqueous samples with no addition (control), sucrose, citric acid, tartaric acid, or a mixture of sucrose and citric acid or sucrose and tartaric acid. No significant difference was found between citric acid and tartaric acid in the suppression of sweetness intensity ratings of sucrose. Further, sucrose suppressed sourness intensity ratings of citric acid and tartaric acid similarly. Culture did not impact the suppression of sweetness intensity ratings of citric or tartaric acid, whereas it did influence sourness intensity ratings. While the Danish consumers showed similar suppression of sourness by both acids, the Chinese consumers were more susceptible towards the sourness suppression caused by sucrose in the tartaric acid-sucrose mixture compared to the citric acid-sucrose mixture. Agglomerative hierarchical cluster analysis revealed clusters of consumers with significant differences in sweetness intensity ratings and sourness intensity ratings. These results indicate that individual differences in taste perception might affect perception of sweet-sour taste interactions, at least in aqueous solutions.

Physical and Adhesive Properties of Cyanoacrylate-Based β-TCP Composites

2007 ◽  
Vol 330-332 ◽  
pp. 419-422 ◽  
Author(s):  
G.S. Lee ◽  
Sang Bae Lee ◽  
Doug Youn Lee ◽  
Kyeong Jun Park ◽  
S.O. Kim ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Citric Acid ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Setting Time ◽  
Tissue Adhesive ◽  
Adhesive Properties ◽  
Composite Systems ◽  
Filling Materials

Histoacryl® (N-butyl-2-cyanoacrylate) has been widely utilized as a tissue adhesive. The aim of this study was to evaluate the physical and adhesive properties of newly developed cyanoacrylate-based β-TCP composite systems. The β-TCP powder was modified on the surface with citric acid to make this material mixed with cyanoacrylate easily. The setting time of acidtreated β-TCP/ Histoacryl® systems was dramatically prolonged and the polymerization heat was significantly decreased compared to that of untreated β-TCP/Histoacryl® system. The shear bond strength of cyanoacrylate-based β-TCP composites decreased with addition of acid-treated β-TCP filler. The compressive strength of β-TCP/Histoacryl® composites increased strongly with increasing the amount of acid-treated β-TCP filler. The cytotoxicity of the β-TCP/Histoacryl® composites decreased with the increasing of the amount of added β-TCP. These results indicated that our novel β-TCP/Histoacryl® composites had the great potential to serve as adhesives or filling materials in the dental field.

Composition of Pomegranate Juice

2012 ◽  
Vol 95 (1) ◽  
pp. 163-168 ◽  
Author(s):  
Dana A Krueger
Keyword(s):  
Citric Acid ◽  
Tartaric Acid ◽  
Malic Acid ◽  
Pomegranate Juice ◽  
Published Data ◽  
Statistical Tools ◽  
Isocitric Acid ◽  
Pee Dee ◽  
Sample Set

Abstract A database of 793 commercial pomegranate juices was analyzed to produce a profile for authentication of pure pomegranate juice. The database consisted of data from a mix of authentic and adulterated samples. Statistical tools were used to reduce the database to a stable sample set of 477 presumably authentic samples. The profile obtained (mean, SD at 16 Brix) are as follows: fructose (g/100 g) 6.83, 0.50; glucose (g/100 g) 6.66, 0.44; sucrose (g/100 g) 0.00, 0.00; sorbitol (g/100 g) 0.00, 0.01; acidity (g/100 g as citric acid) 1.25, 0.32; citric acid (g/100 g) 1.19, 0.30; malic acid (g/100 g) 0.065, 0.034; tartaric acid (g/100 g) 0.00, 0.00; isocitric acid (mg/kg) 63, 21; potassium (mg/kg) 2320, 400; proline (mg/kg) 7, 5; formol value [milliequivalents/100 g] 1.00, 0.24; 13C/12C ratio [o/oo Pee Dee belemnite]–26.4, 0.8. The profile samples had a consistent anthocyanin pattern consisting of four major peaks corresponding to delphinidin-3,5-diglucoside, delphinidin-3-glucoside, cyanidin-3,5-diglucoside, and cyanidin-3-glucoside. Minor peaks corresponding to pelargonidin-3,5-diglucoside and pelargonidin-3-glucoside were also generally present. No maltose, D-malic acid, or tartaric acid were detected in any of the samples. The profile obtained corresponds closely with previously published data.

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