TY - JOUR
T1 - Hot-pressed geopolymer
AU - Ranjbar, Navid
AU - Mehrali, Mohammad
AU - Maheri, Mahmoud R.
AU - Mehrali, Mehdi
PY - 2017
Y1 - 2017
N2 - This research explores the use of simultaneous heating and pressing techniques in order to enhance the mechanical properties of fly ash (FA) based geopolymer under relatively low temperature conditions to ensure minimum-porosity. Four effective parameters of pressing force, alkali activator/FA, duration of hot-pressing and sodium concentration are studied. Together with detailed experimental studies, our results reveal that the most dominant factor is the induced pressure. The main results indicated that the highest compressive strength of the geopolymer (134 MPa) could be obtained by employing the hot pressing, temperature and duration of 41.4 MPa, 350 °C and 20 min, respectively. The microstructure of the hot-pressed specimens showed more developed geopolymer matrix compared with conventional ones leading to higher compressive strength in much shortest time. The improved mechanical properties are generally attributed to the dense structure of the material and higher geopolymer gel production during the hot pressing process. However, further reaction of partially reacted particles improves the mechanical properties over time.
AB - This research explores the use of simultaneous heating and pressing techniques in order to enhance the mechanical properties of fly ash (FA) based geopolymer under relatively low temperature conditions to ensure minimum-porosity. Four effective parameters of pressing force, alkali activator/FA, duration of hot-pressing and sodium concentration are studied. Together with detailed experimental studies, our results reveal that the most dominant factor is the induced pressure. The main results indicated that the highest compressive strength of the geopolymer (134 MPa) could be obtained by employing the hot pressing, temperature and duration of 41.4 MPa, 350 °C and 20 min, respectively. The microstructure of the hot-pressed specimens showed more developed geopolymer matrix compared with conventional ones leading to higher compressive strength in much shortest time. The improved mechanical properties are generally attributed to the dense structure of the material and higher geopolymer gel production during the hot pressing process. However, further reaction of partially reacted particles improves the mechanical properties over time.
KW - A. Acceleration
KW - B. Characterization
KW - D. Alkali activated cement
KW - D. Fly ash
KW - Hot-pressing
UR - http://www.scopus.com/inward/record.url?scp=85019611762&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2017.05.010
DO - 10.1016/j.cemconres.2017.05.010
M3 - Article
AN - SCOPUS:85019611762
SN - 0008-8846
VL - 100
SP - 14
EP - 22
JO - Cement and Concrete Research
JF - Cement and Concrete Research
ER -