TY - JOUR
T1 - Pozzolanic reactivity of recycled glass powder at elevated temperatures
T2 - Reaction stoichiometry, reaction products and effect of alkali activation
AU - Maraghechi, Hamed
AU - Maraghechi, Mahsa
AU - Rajabipour, Farshad
AU - Pantano, Carlo G.
N1 - Funding Information:
The authors gratefully acknowledge support received from the National Science Foundation (NSF) under Grant# CMMI 1030708 awarded to the third author. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. The authors are also thankful to the research staff at Penn State’s Materials Characterization Laboratory (MCL) for their valuable suggestions and assistance.
PY - 2014/10
Y1 - 2014/10
N2 - Use of glass powder as concrete SCM or in development of lime-pozzolan binders could provide environmental and economical benefits. In exposure to an alkaline pore solution, glass powder (GP) dissolves and reacts pozzolanically with calcium hydroxide (CH). In this paper, the stoichiometry and products of this reaction are studied using a CH-GP binder system cured at 60 °C. TGA, selective acid dissolution, SEM/EDS, and QXRD methods are used to quantify the stoichiometry, and characterize the reaction products as a function of age. It is determined that approximately equal masses of CH and GP react with each other and with water to produce C-S-H. Both crystalline and amorphous C-S-H are formed, but the crystalline C-S-H is favored at later ages and higher alkalinities. NaOH-activation accelerates the reactions. However when high alkalinity is maintained, GP continues to dissolve after complete consumption of CH, and forms alkali-silicate gels, which could be expansive and deleterious.
AB - Use of glass powder as concrete SCM or in development of lime-pozzolan binders could provide environmental and economical benefits. In exposure to an alkaline pore solution, glass powder (GP) dissolves and reacts pozzolanically with calcium hydroxide (CH). In this paper, the stoichiometry and products of this reaction are studied using a CH-GP binder system cured at 60 °C. TGA, selective acid dissolution, SEM/EDS, and QXRD methods are used to quantify the stoichiometry, and characterize the reaction products as a function of age. It is determined that approximately equal masses of CH and GP react with each other and with water to produce C-S-H. Both crystalline and amorphous C-S-H are formed, but the crystalline C-S-H is favored at later ages and higher alkalinities. NaOH-activation accelerates the reactions. However when high alkalinity is maintained, GP continues to dissolve after complete consumption of CH, and forms alkali-silicate gels, which could be expansive and deleterious.
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U2 - 10.1016/j.cemconcomp.2014.06.015
DO - 10.1016/j.cemconcomp.2014.06.015
M3 - Article
AN - SCOPUS:84904569113
SN - 0958-9465
VL - 53
SP - 105
EP - 114
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
ER -