Τομέας Οικονομικής Γεωλογίας - Γεωχημείας
Library of the School of Science

2016-02-08

2016

Φραγκούλης Δημήτριος

Μ. Σταματάκης Καθηγητής ΕΚΠΑ

Μελέτη Ποζολανικών Υλικών Βιογενούς και Ηφαιστειακής Προελεύσεως. Παράγοντες που επηρεάζουν την ανάπτυξη αντοχών στο τσιμέντο.

Greek

Study of pozzolannic materials of biogenic and volcanic origin. Factors affecting strength development in cement.

Τhe aim of the present investigation was to determine the effect of biogenic
silica and igneous rocks on the strength development of cement and to compare
the characteristics of the reactive silica originating from different sources
with respect to the various rock formations. According to European regulations,
the amount of reactive silica in a raw material evaluated as pozzolana should
exceed 25% of its mass. Natural pozzolanas include those igneous or
sedimentary rocks that besides the amorphous, glassy phase might contain
amorphous silica (opal-A), opal CT occurring as nanocrystalline silica and
minerals of the zeolite family. These are the minerals that are generally
accepted as the main sources of reactive silica that plays a considerable role
in the strength development of pozzolanic cements. Ιn the present study the
role and importance of the most common minerals comprising part of the
pozzolanic rocks such as clays, quartz and feldspars was evaluated. These
minerals are considered non-reactive in general, therefore their presence in
raw materials intended for use as pozzolanic additives is not desired.
Nevertheless, as inferred by the present study, that assumption might not be
entirely true with their role in the overall strength development during
hydration of pozzolanic cements being the least to say ambiguous, as the issue
of quartz indicated.

Pozzolana, Diatom, Zeolite, Reactive, Cement

Yes

3-8

Yes

260

325

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https://pergamos.lib.uoa.gr/uoa/dl/object/1309064