Preparation and characterization of high-strength calcium silicate boards from coal-fired industrial solid wastes

2015 ◽  
Vol 22 (8) ◽  
pp. 892-900 ◽  
Author(s):  
Zhao Cao ◽  
Yong-dan Cao ◽  
Jin-shan Zhang ◽  
Chun-bao Sun ◽  
Xian-long Li
2021 ◽  
Vol 6 (1) ◽  
pp. 25-36
Author(s):  
Widodo Kushartomo ◽  
Henny Wiyanto ◽  
Daniel Christianto

This research aims to make ultra high strength Reactive Powder Concrete (RPC) with marble powder as one of the components. The use of marble powder can increase Calcium Silicate Hydrate (CSH) and the strength of RPC. The research method used to achieve the objectives is experimental and divided into two steps. The first step is the characterization of a marble and micro silica powder mixture. Stoichiometry calculations are performed to determine the composition of the mixture. The test sample is made in the form of pellets consisting of a mixture of marble powder, micro silica, and water. The water content used is at 30% - 50%. Maintenance is carried out by immersion in water with the temperature of 20oC for 27 days and in steam at temperatures 200oC, 250oC, and 300oC with 2 atm pressure for 4 hours. Material characterization is carried out using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The second step in this research is the RPC compressive strength test. The test sample is made in the form of a cube measuring 50 x 50 x 50 mm. This cube is a mixture of water, cement, micro silica, marble powder, sand, and superplasticizer. Material composition is arranged based on the characterization of the sample pellet test, and maintenance of the sample cube test is carried out as in the sample pellet test.


Author(s):  
Aileen Vandenberg ◽  
Daniel Massucci ◽  
Steven Woltornist ◽  
Douglas Adamson ◽  
Kay Wille
Keyword(s):  

2018 ◽  
Vol 51 (4) ◽  
pp. 46
Author(s):  
N. Venkateswara Rao ◽  
G. Madhusudhan Reddy ◽  
S. Nagarjuna

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1048
Author(s):  
Belén Díaz ◽  
X. Ramón Nóvoa ◽  
Carmen Pérez ◽  
Sheila Silva-Fernández

This research emphasizes the importance of the acid cleaning prior to the phosphate development on high-strength steel rods. It compares the phosphate properties achieved after different acid-pickling conditions. The most common inorganic acids were considered in this study. Additionally, taking into account the environmental and safety concerns of these acids, the assessment of a less harmful organic acid is presented. This study revealed significant differences in the coating morphology and chemical composition whereas no great changes were found in terms of the coating weight or porosity. Thus, hydrochloric and sulfuric acid promote the growth of a Fe-enriched phosphate layer with a less conductive character that is not developed after the pickling with phosphoric acid. The phosphate developed after the citric acid pickling is comparable to that developed after the inorganic acids although with a porosity slightly higher. The temperature of the citric acid bath is an important parameter that affects to the phosphate appearance, composition, and porosity.


2021 ◽  
Vol 22 (11) ◽  
pp. 5781
Author(s):  
Janarthanan Supramaniam ◽  
Darren Yi Sern Low ◽  
See Kiat Wong ◽  
Loh Teng Hern Tan ◽  
Bey Fen Leo ◽  
...  

Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8–10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.


2021 ◽  
pp. 102450
Author(s):  
Shubin Li ◽  
Xiao Wang ◽  
Jiang Zhu ◽  
Zhenyu Wang ◽  
Lu Wang

Author(s):  
Thiago Freitas Almeida ◽  
Flaviane Helena Guedes Leite ◽  
Roberto Trindade Faria ◽  
José Nilson França Holanda

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