Effects of chitosan and zirconia on setting time, mechanical strength, and bioactivity of calcium silicate-based cement

2016 ◽  
Vol 14 (2) ◽  
pp. 135-144 ◽  
Author(s):  
Ali Kamali ◽  
Sirus Javadpour ◽  
Bahar Javid ◽  
Niloofar Kianvash Rad ◽  
Sina Naddaf Dezfuli
Keyword(s):  
Mechanical Strength ◽  
Calcium Silicate ◽  
Setting Time

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 Physico-Chemical Investigation of Endodontic Sealers Exposed to Simulated Intracanal Heat Application: Hydraulic Calcium Silicate-Based Sealers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 728
Author(s):  
David Donnermeyer ◽  
Magdalena Ibing ◽  
Sebastian Bürklein ◽  
Iris Weber ◽  
Maximilian P. Reitze ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Film Thickness ◽  
Physical Properties ◽  
Calcium Silicate ◽  
Setting Time ◽  
Chemical Properties ◽  
Chemical Changes ◽  
Time Flow ◽  
Heat Application

The aim of this study was to gain information about the effect of thermal treatment of calcium silicate-based sealers. BioRoot RCS (BR), Total Fill BC Sealer (TFBC), and Total Fill BC Sealer HiFlow (TFHF) were exposed to thermal treatment at 37 °C, 47 °C, 57 °C, 67 °C, 77 °C, 87 °C and 97 °C for 30 s. Heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate application of warm obturation techniques. Thereafter, specimens were cooled to 37 °C and physical properties (setting time/flow/film thickness according to ISO 6876) were evaluated. Chemical properties (Fourier-transform infrared spectroscopy) were assessed after incubation of the specimens in an incubator at 37 °C and 100% humidity for 8 weeks. Statistical analysis of physical properties was performed using the Kruskal-Wallis-Test (P = 0.05). The setting time, flow, and film thickness of TFBC and TFHF were not relevantly influenced by thermal treatment. Setting time of BR decreased slightly when temperature of heat application increased from 37 °C to 77 °C (P < 0.05). Further heat treatment of BR above 77 °C led to an immediate setting. FT-IR spectroscopy did not reveal any chemical changes for either sealers. Thermal treatment did not lead to any substantial chemical changes at all temperature levels, while physical properties of BR were compromised by heating. TFBC and TFHF can be considered suitable for warm obturation techniques.

Several Common Retarders on Performance of Ultra-Early-Strength Grouting Material

2013 ◽  
Vol 477-478 ◽  
pp. 931-935
Author(s):  
Chang Zheng Sun ◽  
Xiao Ping Zhang ◽  
Hai Nan Zhao ◽  
Qiang Gao
Keyword(s):  
Mechanical Strength ◽  
Setting Time ◽  
Strength Properties ◽  
Preliminary Screening ◽  
Final Setting Time ◽  
Grouting Material ◽  
Early Strength

To explore retarders on performance of ultra-early strength grouting material, Retarder, which are commonly used in the market after a preliminary screening, are further tested and analyzed for initial fluidity, setting time and mechanical strength properties of super early strength grouting material. The results show that: When borax content is 0.4%, the initial fluidity, final setting time, workability, mechanical strength are the best.

scholarly journals Influence of Powder-to-Gel Ratio on Physicochemical Properties of a Calcium Silicate Sealer

2020 ◽  
pp. 337-345
Author(s):  
Fernanda F. E. Torres ◽  
Patricia Perinoto ◽  
Roberta Bosso-Martelo ◽  
Gisselle M. Chávez-Andrade ◽  
Juliane M. Guerreiro-Tanomaru ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Calcium Silicate ◽  
Setting Time ◽  
Repair Material ◽  
Alkaline Ph ◽  
Root Canal Sealer ◽  
Work Time ◽  
Lower Solubility ◽  
Low Solubility ◽  
One Way Anova

Differences in liquid-to-powder ratio can affect the properties of calcium silicate-based materials. This study assessed the influence of powder-to-gel ratio on physicochemical properties of NeoMTA Plus. Setting time (minutes), flow (mm and mm²), pH (at different periods), radiopacity (mm Al) and solubility (% mass loss) were evaluated using the consistencies for root repair material (NMTAP-RP; 3 scoops of powder to 2 drops of gel) and root canal sealer (NMTAP-SE; 3 scoops of powder to 3 drops of gel), in comparison to Biodentine cement (BIO) and TotalFill BC sealer (TFBC). Statistical analysis was performed using one-way ANOVA and Tukey tests (α=0.05). BIO had the shortest setting time, followed by NMTAP-RP and NMTAP-SE. TFBC showed the highest setting time and radiopacity. BIO, NMTAP-RP, and NMTAP-SE had similar radiopacity. All materials promoted an alkaline pH. NMTAP-RP/SE presented lower solubility than BIO and TFBC. Regarding the flow, TFBC had the highest values, followed by NMTAP-SE, and NMTAP-RP. BIO had the lowest flow. In conclusion, NMTAP in both powder-to-gel ratios showed high pH and low solubility. The increase in the powder ratio decreased the setting time and flow. These findings are important regarding the proper consistency and work time to clinical application.

Comparative Assessment of Effectiveness of Calcium Silicate Dispersions Produced Using Sucrose and Lactose as Components of Composite Cement Binder

2021 ◽  
Vol 1017 ◽  
pp. 11-20
Author(s):  
Evgeny A. Shoshin ◽  
Valeria V. Strokova ◽  
Zheng Mao Ye
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Calcium Silicate ◽  
Setting Time ◽  
Inhibitory Effect ◽  
Main Element ◽  
Residual Content ◽  
Nucleation Effect ◽  
Wide Range

Silicate micro- and nano-additives are multifunctional in relation to cement systems. Their application can solve a wide range of technological problems while maintaining the economic efficiency of technical solutions. The effect of silicate additives and fillers is determined by their level of dispersion, due to which the technologies for producing nano- and submicro-sized dispersed materials are being developed. The combination of mechanochemical synthesis of modified calcium hydrosilicates with subsequent thermolysis makes it possible to produce calcium silicate dispersions (SCD), which differ in polymodality of the fractional composition including submicro (10–7–10–6 m) and microdimensional (≥10–6 m) modes. The main element of the technology is the use of modifying carbohydrate, which acts as a stabilizer of hydrated phases of silicates. A comparative study of SCD produced using sucrose (sSCD) and lactose (lSCD) revealed the effect of these carbohydrates on the properties of sSCD and lSCD, as well as their effectiveness as a component of cementitious composite binder. It was found that the level of adsorption of modifying carbohydrate determines the physical properties of SCD (granulometry, specific surface area). The relatively high residual content of free sucrose (0.24%) in the composition of sSCD prevents the consolidation of silicates nanoparticles formed during the thermolysis, causes a high content of submicro sized fractions and a high specific surface area with sSCD (26.3 ± 0.7 m2/g). Lactose is absorbed by the silicate phase; the residual content of free lactose does not exceed 0.028% of lSCD. The low content of stabilizing carbohydrate contributes to the development of nanoparticle consolidation, a decrease in the specific surface area of lSCD to 13.0 ± 0.2 m2/g and content of submicrosized fractions. The residual content of free carbohydrates and particle size characteristics of sSCD and lSCD determine the nature of their influence on Cement-SCD-based concrete setting and hardening. The presence of residual sucrose in the composition of sSCD and fine fractions determines the competitive nature of the processes of retardation of hardening and acceleration of hardening of the cement system due to the nucleation effect, as a result of which the curve of the setting time is extreme. In addition, the inhibitory effect of sucrose reduces the strength of concrete on the 7th day. By the 28th day, the inhibitory effect of sucrose has been overcome, and concrete samples demonstrate an 18% increase in compressive strength with a sSCD content of 30%. The low content of residual free lactose in the composition of lSCD causes the nucleation effect. As a result, there is a monotonous reduction in the setting time of concrete mix with an increase in the content of lSCD in the composition of HF, as well as a significant increase in concrete strength (up to 127%) on the 7th day. At the same time, on the 28th day the strength of concrete increases slightly

scholarly journals Influence of the Treatment Temperature on the Microstructure and Hydration Behavior of Thermoactivated Recycled Cement

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3937
Author(s):  
Sofia Real ◽  
Ana Carriço ◽  
José Alexandre Bogas ◽  
Mafalda Guedes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Strength ◽  
Water Demand ◽  
Isothermal Calorimetry ◽  
Setting Time ◽  
Treatment Temperature ◽  
Diffraction Field ◽  
Resonance Spectroscopy ◽  
Scanning Electron

This paper intends to contribute to a better knowledge of the production and rehydration of thermoactivated recycled cement and its incorporation in cement-based materials. To this end, the influence of the treatment temperature on the properties of recycled cements and recycled cement pastes was assessed by means of a wide array of tests. Anhydrous recycled cement as well as the resulting pastes were characterized through density and particle size, water demand and setting time, thermogravimetry, X-ray diffraction, field emission gun scanning electron microscopy, isothermal calorimetry, 29Si nuclear magnetic resonance spectroscopy, flowability, mechanical strength, mercury intrusion porosimetry and scanning electron microscopy. The treatment temperature had a significant influence on the dehydration and hydration of recycled cement, essentially resulting in the formation of C2S polymorphs of varying reactivity, which led to pastes of different fresh and hardened behaviors. The high water demand and the pre-hydration of recycled cement resulted in high setting times and low compressive strengths. The highest mechanical strength was obtained for a treatment temperature of 650 °C.

Novel Fluoride-doped Calcium-silicate cement for dental applications. The effect of Bi2O3 and BaSO4 radiopacifier agents on setting time

2010 ◽  
Vol 150 ◽  
pp. 465-465
Author(s):  
Maria Giovanna Gandolfi ◽  
Andrea Colin ◽  
Giovanni Luca Acquaviva ◽  
Stefano Chersoni ◽  
Fabio Fava ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
Setting Time ◽  
Calcium Silicate Cement ◽  
Dental Applications

Research Progress for Gypsum Retarder

2014 ◽  
Vol 1015 ◽  
pp. 272-275
Author(s):  
Xiao Qiong Ren ◽  
Ya Nan Wu ◽  
Ying Li ◽  
Mo Han Lin ◽  
Feng Qing Zhao
Keyword(s):  
Organic Acids ◽  
Mechanical Strength ◽  
Building Materials ◽  
Setting Time ◽  
Strength Loss ◽  
Raw Material ◽  
Research Progress ◽  
High Quality ◽  
Protein Rich ◽  
Waste Mycelium

Gypsum retarder is an important additive of building materials. Commercial gypsum retarders are mainly composed of four types: organic acids, phosphates, protein and composite retarder. Although the effects of organic acids and phosphates have better retarding performances, there is still obvious a shortcoming that the mechanical strength reduces largely with time going by. Protein based retarders prolong the setting time of hemihydrates with less strength loss and higher costs. The gypsum retarder from waste mycelium, a protein-rich raw material, solved the problem of the disposal of waste mycelium from anti-biotic plants, while producing high-quality retarder for gypsum, shows potential for future.

Wollastonite as a Flux for Ceramics Bodies

2012 ◽  
Vol 727-728 ◽  
pp. 1016-1021 ◽  
Author(s):  
S.R. Bragança ◽  
H.C.M Lengler ◽  
Carlos Pérez Bergmann
Keyword(s):  
Mechanical Strength ◽  
Mechanism Of Action ◽  
Calcium Silicate ◽  
Raw Materials ◽  
Alkali Feldspar ◽  
Temperature Phase ◽  
Technological Properties ◽  
Silicate Mineral ◽  
Technical Properties ◽  
Ceramic Flux

Wollastonite is a calcium silicate mineral natural or synthetic. Commercial wollastonite starts to melt at about 1450°C and can not be considered a "flux" as alkali feldspar. For this function, it depends on the reaction with other raw materials. Faced with this, came the goal of this work which was to investigate the mechanism of action of wollastonite as a ceramic flux. The use of wollastonite in ceramic bodies was investigated by analysis of its reactivity with other materials such as quartz, kaolin, talc and feldspar. It was analyzed the technological properties of the final parts, especially in relation to the firing temperature, phase formation and technological properties (mechanical strength, porosity, etc.). The results of this characterization showed that the technical properties of the parts are developed according to commercial porcelain products.

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