Fly-ash-based geopolymer composites incorporating cold-bonded lightweight fly ash aggregates

2021 ◽  
Vol 272 ◽  
pp. 121963
Author(s):  
Hatice Öznur Öz ◽  
Hasan Erhan Yücel ◽  
Muhammet Güneş ◽  
Turan Şevki Köker
Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 511 ◽  
Author(s):  
Eyerusalem A. Taye ◽  
Judith A. Roether ◽  
Dirk W. Schubert ◽  
Daniel T. Redda ◽  
Aldo R. Boccaccini

Novel hemp fiber reinforced geopolymer composites were fabricated. The matrix was a new geopolymer based on a mixture of red mud and fly ash. Chopped, randomly oriented hemp fibers were used as reinforcement. The mechanical properties of the geopolymer composite, such as diametral tensile (DTS) (or Brazilian tensile) strength and compressive strength (CS), were measured. The geopolymer composites reinforced with 9 vol.% and 3 vol.% hemp fiber yielded average DTS values of 5.5 MPa and average CS values of 40 MPa. Scanning electron microscopy (SEM) studies were carried out to evaluate the microstructure and fracture surfaces of the composites. The results indicated that the addition of hemp fiber is a promising approach to improve the mechanical strength as well as to modify the failure mechanism of the geopolymer, which changed from brittle to “pseudo-ductile”.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1015 ◽  
Author(s):  
Emy Aizat Azimi ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Petrica Vizureanu ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Andrei Victor Sandu ◽  
...  

A geopolymer has been reckoned as a rising technology with huge potential for application across the globe. Dolomite refers to a material that can be used raw in producing geopolymers. Nevertheless, dolomite has slow strength development due to its low reactivity as a geopolymer. In this study, dolomite/fly ash (DFA) geopolymer composites were produced with dolomite, fly ash, sodium hydroxide, and liquid sodium silicate. A compression test was carried out on DFA geopolymers to determine the strength of the composite, while a synchrotron Micro-Xray Fluorescence (Micro-XRF) test was performed to assess the elemental distribution in the geopolymer composite. The temperature applied in this study generated promising properties of DFA geopolymers, especially in strength, which displayed increments up to 74.48 MPa as the optimum value. Heat seemed to enhance the strength development of DFA geopolymer composites. The elemental distribution analysis revealed exceptional outcomes for the composites, particularly exposure up to 400 °C, which signified the homogeneity of the DFA composites. Temperatures exceeding 400 °C accelerated the strength development, thus increasing the strength of the DFA composites. This appears to be unique because the strength of ordinary Portland Cement (OPC) and other geopolymers composed of other raw materials is typically either maintained or decreases due to increased heat.


2017 ◽  
Vol 150 ◽  
pp. 179-189 ◽  
Author(s):  
Fang Xu ◽  
Xin Deng ◽  
Chao Peng ◽  
Jing Zhu ◽  
Jianping Chen

2012 ◽  
Vol 626 ◽  
pp. 892-895 ◽  
Author(s):  
Rafiza Abd Razak ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
I. Khairul Nizar ◽  
D. Hardjito ◽  
...  

Aggregates are popular for use in concrete and lightweight concrete applications. Recent research shows that the by-product materials such as fly ash can be used as raw material in producing aggregates and lightweight aggregates. The usage of this material can improve the quality of the aggregates produced compared to conventional in term of structurally strong, physically stable, durable, and environmentally inert. This paper summarized the process and mechanical testing on the fly ash aggregates and lightweight aggregates to be used in concrete.


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