alkali silicate
Recently Published Documents


TOTAL DOCUMENTS

375
(FIVE YEARS 38)

H-INDEX

42
(FIVE YEARS 4)

2022 ◽  
Vol 580 ◽  
pp. 121389
Author(s):  
Amin Abd El-Moneim ◽  
Hassan A. Hashem ◽  
A.A. El-Namrouty ◽  
Asmaa Atef

Author(s):  
Alexander G. Rakoch ◽  
Tran Van Tuan ◽  
Zukhra V. Khabibullina ◽  
Carsten Blawert ◽  
Maria Serdechnova ◽  
...  

Gels ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Claus Henning Rüscher ◽  
Ludger Lohaus ◽  
Fongjan Jirasit ◽  
Hervé Kouamo Tchakouté

Lime-sand bricks of different ages were investigated using IR-spectroscopy, thermogravimetry, and X-ray diffraction/scattering. After subtraction of the dominant quartz contribution (80%), the IR spectra show the absorption peaks of the hydrothermally formed binder phases. The spectra also show the alteration of the binder during ageing under atmospheric conditions by the influence of CO2 forming carbonate and a condensed SiO2-gel (secondary gel). The alteration could also be proven in X-ray pattern, obtaining a separation between crystalline CSH and amorphous contributions in the freshly produced lime-sand brick, too. Here, the formation of CSHamorph could be understood as a precursor state (primary gel) to the crystallization of CSH phases. X-ray patterns of aged bodies of alkali-silicate solution activated slags (AAS), CEM-I/CEM-III pastes, and CEM-I concrete indicate that in all cases a similar amorphous CSH-type phase (CSHamorph) was formed, which is responsible for the hardening properties as the glue. The main X-ray peak of CSHamorph obtained using CuKα-radiation with a usual diffractometer is observed between 24° and 35° 2 Theta with maximum at about 29° 2 Theta, whereas it appears much more broadly distributed between 15° and 35° 2 Theta with maximum between 26° and 28° 2 Theta for a geopolymer body prepared using the reaction of alkali-silicate solution and metakaolin (AAMK). This is due to the network formed by siloxo and sialate units in the case of AAMK, given that any crystallization can be ruled out. The origin of increasing mechanical strength during the ageing of AAS mortars must be due to further crosslinking of the preformed siloxo chains. Thermal treatment up to 800 °C leads to a complete loss of any mechanical strength of the CEM pastes due to the destruction of crystalline CSH-phases, whereas geopolymer bodies maintain their strength. Implications for next generation concrete include that cement clinker could be completely replaced by using a using alkali silcate solution technology for gel formation.


2021 ◽  
Vol 572 ◽  
pp. 121094
Author(s):  
T. Waurischk ◽  
S. Reinsch ◽  
T. Rouxel ◽  
H. Behrens ◽  
J. Deubener ◽  
...  

Author(s):  
Ilya Reshetov ◽  
Valentina Zhurikhina ◽  
Dmitry Tagantsev ◽  
Vladimir Kaasik ◽  
Alexey Redkov ◽  
...  

2021 ◽  
Vol 13 (16) ◽  
pp. 9203
Author(s):  
Roberto Evaristo de Oliveira Neto ◽  
Juliana de Melo Cartaxo ◽  
Alisson Mendes Rodrigues ◽  
Gelmires de Araújo Neves ◽  
Romualdo Rodrigues Menezes ◽  
...  

Tailing incorporation into mortars has been the subject of much research in recent years. Despite this, most of these studies did not investigate the harmful effects resulting from the exposure of such mortars to an environment containing aggressive agents. This work investigated the effects of perlite tailing addition into mortars containing cement CP V-ARI MAX and hydrated lime. The raw materials were subjected to chemical characterization (X-ray fluorescence (XRF)) and mineralogical (X-ray diffraction (XRD)), while the samples immersed in 1 N NaOH solution were characterized by XRD, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and compression strength (CS). The results showed the harmful effects of incorporating perlite tailings into the mortar investigated. Such a degradation was proven by linear expansion and compressive strength experiments accomplished in the samples after the test of resistance to an alkali–silicate reaction.


2021 ◽  
Vol 292 ◽  
pp. 129551 ◽  
Author(s):  
Luca Bertolla ◽  
Ivo Šulák ◽  
Jiří Buršík ◽  
Ivo Dlouhý ◽  
Jiří Smilek ◽  
...  

2020 ◽  
Vol 46 (6) ◽  
pp. 510-513
Author(s):  
D. A. Jurchenko ◽  
S. K. Evstropiev ◽  
N. V. Nikonorov

Sign in / Sign up

Export Citation Format

Share Document