scholarly journals Biocompatibility and pro-mineralization effect of tristrontium aluminate cement for endodontic use

2022 ◽  
Author(s):  
Sherif Adel ◽  
Kentaro Hashimoto ◽  
Nobuyuki Kawashima ◽  
Takahiro Wada ◽  
Motohiro Uo ◽  
...  
Keyword(s):  
Aluminate Cement

scholarly journals The Influence of Water Reducing Agents on Early Hydration Property of Ferrite Aluminate Cement Paste

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 731
Author(s):  
Chunlong Huang ◽  
Zirui Cheng ◽  
Jihui Zhao ◽  
Yiren Wang ◽  
Jie Pang
Keyword(s):  
Setting Time ◽  
Critical Role ◽  
Hydration Product ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Hydration Process ◽  
Early Hydration ◽  
Cement Pastes ◽  
Hydration Rate ◽  
Aluminate Cement

The ferrite aluminate cement (FAC) could rapidly lose fluidity or workability due to its excessive hydration rate, and greatly reduce the construction performance. Chemical admixtures are commonly used to provide the workability of cement-based materials. In this study, to ensure required fluidity of FAC, chemically different water reducing agents are incorporated into the FAC pastes. The experiments are performed with aliphatic water reducing agent (AP), polycarboxylic acid water reducing agent (PC) and melamine water reducing agent (MA), respectively. Influence of the water reducing agents on fluidity, setting time, hydration process, hydration product and zeta potential of the fresh cement pastes is investigated. The results show that PC has a better dispersion capacity compared to AP and MA. Besides decreasing water dosage, PC also acts as a retarder, significantly increasing the setting times, delaying the hydration rate and leading to less ettringite in the hydration process of FAC particles. The water reducing agents molecules are adsorbed on the surface of positively charged minerals and hydration products, however, for PC, steric hindrance from the long side chain of PC plays a critical role in dispersing cement particles, whereas AP and MA acting through an electrostatic repulsion force.

scholarly journals Physicochemical, Mineralogical, and Mechanical Properties of Calcium Aluminate Cement Concrete Exposed to Elevated Temperatures

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3855
Author(s):  
Amirmohamad Abolhasani ◽  
Bijan Samali ◽  
Fatemeh Aslani
Keyword(s):  
Temperature Rise ◽  
Calcium Aluminate ◽  
Elevated Temperatures ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Calcium Aluminate Cement ◽  
Cement Concrete ◽  
Sem Images ◽  
Strength Deterioration ◽  
Aluminate Cement

One commonly used cement type for thermal applications is CAC containing 38–40% alumina, although the postheated behavior of this cement subjected to elevated temperature has not been studied yet. Here, through extensive experimentation, the postheated mineralogical and physicochemical features of calcium aluminate cement concrete (CACC) were examined via DTA/TGA, X-ray diffraction (XRD), and scanning electron microscopy (SEM) imaging and the variation in the concrete physical features and the compressive strength deterioration with temperature rise were examined through ultrasonic pulse velocity (UPV) values. In addition, other mechanical features that were addressed were the residual tensile strength and elastic modulus. According to the XRD test results, with the temperature rise, the dehydration of the C3AH6 structure occurred, which, in turn, led to the crystallization of the monocalcium dialuminate (CA2) and alumina (Al2O3) structures. The SEM images indicated specific variations in morphology that corresponded to concrete deterioration due to heat.

scholarly journals Study of the Electrical Properties of Aluminate Cement Adhesives for Porcelain Insulators

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2232
Author(s):  
Huiwen Wan ◽  
Zhangyin Hu ◽  
Gang Liu ◽  
Jiadong Xiao
Keyword(s):  
Compressive Strength ◽  
Electrical Properties ◽  
Silica Fume ◽  
Drying Time ◽  
Pore Connectivity ◽  
Cement Based Materials ◽  
Porcelain Insulators ◽  
Materials Used ◽  
The Cost ◽  
Aluminate Cement

Electrical properties are one of the essential parameters of cement-based materials used in suspension porcelain insulators. This paper studied the electrical properties of aluminate cement adhesives (ACA) containing silica fume (SF), as well as their compressive strength and porosity. The results indicated that the addition of silica fume improved the resistivity of ACA under a saturated state (relative humidity is 50%). This was mainly attributed to the decrease of the ACA’s pore connectivity due to the SF’s filling effect. However, the early compressive strength of ACA was slightly reduced by the addition of SF. Under an unsaturated state, the ACA’s resistivity without the SF gradually exceeded that with the SF at the extension of drying time. The nuclear magnetic resonance (NMR) results indicated that the addition of SF content increased the ACA’s porosity; for the tiny pores especially, (the size less than 25 nm), this increased by 3.4%. Meanwhile, the addition of SF increased the tortuosity of the ACA’s conductive channels, which could improve its resistivity. Therefore, SF is recommended to be used in cement-based adhesives on insulators to lower the cost and improve the resistivity.

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