Naslov
Parameters of early hydration of cement systems as indicators of succesful solidification and stabilization of waste zeollite from zinc-plating plant

Autori
Dabić, Pero ; Krolo, Petar ; Barbir, Damir

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of the first Croatian Symposium on Zeolites / Bronić, Josip ; Trgo, Marina ; Hrenović, Jasna ; Margeta, Karmen - Zagreb : Hrvatska zeolitna udruga (HZU), 2008, 63-67

ISBN
978-953-55373-0-4

Skup
1. Hrvatski zeolitni simpozij

Mjesto i datum
Split, Hrvatska, 26.09.2008. - 27.09.2008

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
waste zeolite ; solidification / stabilization ; cement hydration ; hydration heat ; specific conductivity

Sažetak
For solidification and stabilization of harmful waste materials to be successful, the addition should affect the hydration of the cement component of the system as little as possible and the harmful component should not be eventually released from the cement stone. Hydration of clinker minerals is accompanied with a series of reactions that cannot be traced individually. It is necessary to block hydration at certain times and determine the amount of un-reacted clinker mineral in the system or the amount of products formed. Such discontinuous methods of tracing reactions are time consuming and require costly analytic equipment (XRD, XRF, TA ...). The course of hydration can be traced by monitoring the effects due to hydration reactions, such as hydration heat, changes in the pH value and specific conductivity of the cement paste, development of strength etc. Hydration is often traced by recording released heat developed in hydration reactions in clinker minerals, added gypsum, free CaO and MgO, yielding a result curve well described in literature. By analysing the hydration heat curves it is possible to determine the intensity and duration of individual processes, and kinetic parameters of hydration, rate and degree of hydration at specific moments. One of methods for continuous tracing of heat released during hydration of cement constituents is microcalorimetry. Continuous determination of specific conductivity of hydrating cement paste indicates the start of binding, which is an important practical parameter for determination of the effect of the addition on hydration of cement composite. Replacement additions to cement additionally complicate the hydration processes, especially if the addition is active and if interactions between the addition and cement take place forming various reaction products. The products formed affect the dynamics and kinetics of cement hydration and the solidification process, modifying both the composition and the properties of the cement gel formed in the composite.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

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