Abstracts Book - IMRC 2018

• SE2-P047
EFFECT OF ALKALINE ACTIVATOR TYPE ON CEMENTS BASE
WASTE GLASS-LIMESTONE
Andrea Estefanía Córdova Sánchez 1 , Ulises Avila López 1 , J Iván Escalante Garcia 2 , Marisol
Gallardo Heredia 1
1 Universidad Autónoma de Coahuila, Facultad de Ingeniería, Mexico. 2 Centro de Investigación y
de Estudios Avanzados del IPN - CINVESTAV Unidad Saltillo, Cerámicos, Mexico.
Investigation were carried out about to characterize the reactivity and strength
of pastes of alternative cements based on urban waste glass and limestone
activated by NaOH, Na 2 CO 3 and a mixture of these. The factors considered were
the CaO/SiO 2 ratio, fraction of preactivated binder, type of alkaline activator,
Na 2 O concentration, water/binder ratio and curing temperature; their effect was
analyzed on the compressive strength, the reaction products and
microstructure. Twelve pastes were prepared, the results suggest that the
activation with Na 2 CO 3 promotes a greater development of mechanical
properties; however, at later curing age it can generate structural instability,
causing the decrease of compressive strength as a result of the formation of
cracks, which could be a result of the formation of expansive phases. On the
other hand, the activation with NaOH promoted greater strengths in early ages
of curing; however, later the development of strength was lower compared to
the activation with the other activators. The activator that promoted satisfactory
compressive strength without compromising the structural stability in late ages
or under water was the Na 2 CO 3 /NaOH mixture, the strength of this paste was of
42 MPa. The main reaction products found, by X-ray diffractometry, thermal
analysis and scanning electron microscopy in all formulations were pirssonita
(Na 2 Ca(CO 3 ) 2·2H 2 O), gaylussite (Na 2 Ca(CO 3 ) 2·5H 2 O), calcium silicate hydrate (C-S-
H) and a silica gel type phase. For all alkaline activators used the hydration
products seemed finely intermixed, C-S-H intermixed with silica gel type phase
and the gaylussite intermixed with pirssonite.
Acknowledgment: The National Council of Sciece and Technology (Conacyt) and
the Program for Teacher Professional Development (PRODEP) are
acknowledged for the scholarship to A. E. Córdova Sánchez and for the
financial support of the project 511-6 / 17-8565, respectively.
Keywords: Waste glass, Alkali activation, Limestone
Presenting authors email: andrea_cordova23@outlook.es