Effects of hydroxyethyl methyl cellulose ether on the hydration and compressive strength of calcium aluminate cement

2019 ◽  
Vol 140 (2) ◽  
pp. 545-553 ◽  
Author(s):  
Zhongping Wang ◽  
Yating Zhao ◽  
Long Zhou ◽  
Linglin Xu ◽  
Guizhi Diao ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Calcium Aluminate ◽  
Methyl Cellulose ◽  
Calcium Aluminate Cement ◽  
Cellulose Ether ◽  
Aluminate Cement

PGA Fiber Reinforced Calcium Aluminate Cement for Orthopaedic Application

2016 ◽  
Vol 852 ◽  
pp. 1188-1193
Author(s):  
Yan Ni Tan ◽  
Liu Yong ◽  
Xiang He ◽  
Wen Wang ◽  
Dong Duan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Calcium Aluminate ◽  
Fiber Composite ◽  
Calcium Aluminate Cement ◽  
Lower Strength ◽  
Crystalline Phases ◽  
Oxide Hydrate ◽  
In Vitro Biocompatibility ◽  
Aluminate Cement

Calcium aluminate cement (CAC) is a penitential candidate for bone replacements with good bioactivity but relative lower strength. In this study, biodegradable PGA fiber was incorporated into the CAC paste in order to improve the strength of the material. And MC3T3 cells were seeded on the surface of CAC and CAC/fiber to study their in vitro biocompatibility. The results indicate that the PGA fiber can improve the compressive strength of CAC without changing the crystalline phases and micromorphology. Calcium aluminate oxide hydrate, katoite and Gibbsite crystals were detected by XRD. Plate-like crystals can be observed under FESEM. The MC3T3 cells were attached well on both CAC and CAC/fiber composite, indicating their good in vitro biocompatibility. In summary, fiber reinforcement can be an effective way to improve the properties of calcium aluminate cement for orthopaedic application.

Different Chlorides Attack on the Hydration of Calcium Aluminate Cement at 5~40°C

2021 ◽  
Vol 1036 ◽  
pp. 247-254
Author(s):  
Zhong Ping Wang ◽  
Yu Ting Chen ◽  
Xiang Peng ◽  
Ling Lin Xu
Keyword(s):  
Compressive Strength ◽  
Calcium Aluminate ◽  
Physical Adsorption ◽  
Calcium Aluminate Cement ◽  
Binding Ability ◽  
Cement Pastes ◽  
Thermal Analyzer ◽  
Chloride Attack ◽  
Different Temperatures ◽  
Aluminate Cement

Calcium aluminate cement (CAC) has excellent resistance to seawater erosion, but the mechanism remains to be explored. Effects of NaCl and CaCl2 on the hydration of CAC at 5, 20 and 40°C were investigated in this paper by X-ray diffraction(XRD), thermal analyzer(TG-DSC), scanning electron microscopy(SEM), acoustic and electroacoustic spectrometer. Results show that the varieties of chlorides have great impacts on the chloride binding ability, mechanical properties and microstructure of cement pastes at different temperatures. At 5°C and 20°C, the formation of C2AH8 is suppressed by chloride attack. Though the addition of NaCl promotes the formation of CAH10, CaCl2 leads to a denser microstructure and the improvement in compressive strength. At 40°C, C2AH8 disappears by chloride attack, while C3AH6 and Friedel’s salt increase. Comparing with the attack of CaCl2, NaCl contributes to the formation of C3AH6. Therefore, it results in a the retraction in compressive strength, ascribing to a coarser structure. In addition, although NaCl is superior in chemical binding ability, CaCl2 has better physical adsorption ability which dominants the binding process, and thus leading to greater amount of bonded chloride than that with NaCl. This research provides the oretical basis for the application of CAC in marine environment.

Effect of wollastonite and a bioactive glass-ceramic on the in vitro bioactivity and compressive strength of a calcium aluminate cement

2018 ◽  
Vol 44 (16) ◽  
pp. 19077-19083
Author(s):  
G. García-Álvarez ◽  
J.C. Escobedo-Bocardo ◽  
D.A. Cortés-Hernández ◽  
J.M. Almanza-Robles ◽  
B.A. Sánchez-Escobedo
Keyword(s):  
Compressive Strength ◽  
Bioactive Glass ◽  
Calcium Aluminate ◽  
Glass Ceramic ◽  
Calcium Aluminate Cement ◽  
In Vitro Bioactivity ◽  
Aluminate Cement

Evaluation of strength and set behavior of mortar containing shotcrete set accelerators

2008 ◽  
Vol 35 (4) ◽  
pp. 400-407 ◽  
Author(s):  
Jincheol Kim ◽  
Jonghyun Ryu ◽  
R. D. Hooton
Keyword(s):  
Compressive Strength ◽  
Calcium Aluminate ◽  
Setting Time ◽  
Strength Loss ◽  
Test Methods ◽  
Calcium Aluminate Cement ◽  
Cement Matrix ◽  
Early Age ◽  
Rapid Setting ◽  
Aluminate Cement

The influence of rapid-set accelerating admixtures on the setting behavior and early-age strength of a cement matrix was investigated to evaluate the appropriateness of the specification and test methods for shotcrete set accelerators. The results verified two different rapid setting behaviors according to the types of accelerator. The aluminate-base and the calcium aluminate cement-base accelerators facilitate hydration by formation of a calcium aluminate solid solution, whereas the alkali-free set accelerating agents present rapid setting time by the formation of ettringite. It was also found that the Vicat test was more desirable than the Gillmore test as the standard for setting time evaluation. Additionally, the cement mortar mixed with the aluminate-base and the calcium aluminate cement-base accelerators exhibited very fast development of early-age compressive strength. However, most of the set accelerators, except for alkali-free accelerators, failed to satisfy the specification because of greater than 40% compressive strength loss at 28 d.

Effect of basalt and polypropylene fibers on crumb rubber mortar with Portland cement and calcium aluminate cement binders: Strength and artificial neural network prediction model

2021 ◽  
pp. 147776062110629
Author(s):  
Saghar Baghban ◽  
Kim Hung Mo ◽  
Zainah Ibrahim ◽  
Mohammed KH Radwan ◽  
Syed Nasir Shah
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Calcium Aluminate ◽  
Crumb Rubber ◽  
Calcium Aluminate Cement ◽  
Fiber Types ◽  
Aluminate Cement

This paper aims to study the influence of basalt fiber (BF) and polypropylene fiber (PPF) in crumb rubber (CR) mortar made of two different types of cement, including ordinary Portland cement (OPC) and calcium aluminate cement (CAC). CR was used to partially (5%, 10%, 15%, and 20% by volume) replace the fine aggregate in OPC and CAC mortars. BF and PPF were added (0.1%, 0.3%, and 0.5% by total volume) in the CR mortars. The consistency, density, compressive, and flexural strength of cement mortars were investigated. The use of CAC cement slightly increased the consistency; however, the results showed that the CR replacement and the addition of both fiber types tend to reduce the consistency in OPC and CAC mortars. Significant reduction in the density of fiber-added CR mortar was found with increasing CR content, whereas the influence of both PPF and BF was minimal. The fiber-added CR mortar made of both binder and fiber types in general exhibited a reducing trend in the 28 days compressive strength when increasing CR and fiber contents. Nevertheless, an enhancement in the compressive strength of CAC mortar with 20% CR was found with the addition of 0.1% of both fibers. The use of CR and addition of the fibers generally decreased the flexural strength of mortar made of both binder types; however, the addition of 0.3% BF in mortars containing 15–20% CR positively affected the flexural performance. Finally, the artificial neural network (ANN) approach demonstrated the ability to predict the compressive strength of fiber-added CR mortars. The model showed a considerably insignificant mean square error (MSE) of 1.4–1.5 and high plot regression (R) results of 0.97–0.98.

scholarly journals Physical properties and hydration evolution of dispersant containing calcium aluminate cement compositions for endodontic applications

Cerâmica ◽  
2014 ◽  
Vol 60 (355) ◽  
pp. 366-370 ◽  
Author(s):  
A. P. Luz ◽  
V. C. Pandolfelli
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Calcium Aluminate ◽  
Dimensional Change ◽  
Calcium Aluminate Cement ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
X Ray ◽  
Polymeric Dispersant ◽  
Aluminate Cement

The purpose of this study was to evaluate the physical properties and hydration evolution of calcium aluminate cement (CAC) compositions containing an advanced dispersant. The compressive strength, dimensional change, apparent porosity and quantitative X ray diffraction analysis (XRD) of the cement pastes were carried out over 1-15 days of curing (with the samples immersed in distilled water) at 37 ºC. The addition of a polymeric dispersant to the selected CAC (Secar 71) resulted in higher, but suitable expansion of the cement samples, and improved uniaxial compressive strength reaching values in the range of 73-87 MPa after 15 days. Quantitative XRD results also showed that C3AH6 and Al(OH)3 were the main phases detected during the cement hydration process, but CAH10 and C2AH8 were also found due to the higher water availability in the curing environment. According to the attained results, it could be concluded that the dispersant containing calcium aluminate cement compositions have the potential to be used as endodontic materials.

Influence of Mixing Liquid on the Properties of Calcium Aluminate Cement

2008 ◽  
Vol 396-398 ◽  
pp. 241-244 ◽  
Author(s):  
L. Morejón-Alonso ◽  
Luis Alberto Santos ◽  
R. García Carrodeguas
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Calcium Phosphate ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Hydration Reaction ◽  
Potential Toxicity ◽  
Ca Ions ◽  
Aluminate Cement ◽  
Hydrated Calcium

The effect of using Na2HPO4 solution as mixing liquid in the physicochemical and mechanical properties of calcium aluminate cement (CAC), with a view to a possible reinforcement additive of conventional α-TCP-based CPC was studied. The results showed that the degree of the hydration reaction of CaAl2O4 (CA) increased when Na2HPO4 solution was used as mixing liquid. The porosity of cement was also lower (37.9 ± 1.3 %) than for H2O (33.2 ± 3.6 %). The values of compressive strength for cements prepared with both mixing liquids were lower than 3 MPa due to the excessive L/P ratio employed and large porosity. After immersion in SBF, only the Al(OH)3 hydrate is observed and no other crystalline hydrated calcium aluminate nor calcium phosphate was formed in any of the cements. Both cements released Ca ions to, and removed P ions from SBF, being this effect more remarkable when Na2HPO4 was used. As for other CAC, no Al was released to the SBF and no potential toxicity due to this ion should be expected.

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