Μελέτη καταλληλότητας του τόφφου των περιοχών Cesinovo και Strmos ως ποζολάνη στο τσιμέντο

Στη Πρώην Γιουγκοσλαβική Δημοκρατία της Μακεδονίας (ΠΓΔΜ) υπάρχουν δύο τοποθεσίες οι Strmos και Cesinovo, οι οποίες βρίσκονται στη παλαιοηφαιστειακή περιοχή Kratovo – Zletovo, δυτικά του βουνού Osogovo. Λόγω της ηφαιστειακής δραστηριότητας του Καινοζωικού στις τοποθεσίες αυτές υπάρχουν αποθέσεις τόφφων, οι οποίοι είναι ηφαιστειακά πετρώματα που σχηματίζονται από το μίγμα ηφαιστειακών πετρωμάτων και θραυσμάτων ορυκτών σε μία μήτρα ηφαιστειακής τέφρας. Οι τόφφοι, ως ηφαιστειακό υλικό, θα μπορούσαν να αποτελέσουν φυσική ποζολάνη στο μείγμα σκυροδέματος. Για να αποτελέσουν όμως φυσική ποζολάνη πρέπει να έχουν κάποιες ιδιότητες. Οι ιδιότητες μιας ποζολάνης, εξαρτώνται από τη χημική και ορυκτολογική της σύσταση, από τα φυσικά χαρακτηριστικά και καθορίζουν τελικά αν η ποζολάνη θα έχει ενεργότητα ή όχι. Για να μελετηθούν λοιπόν αν οι τόφφοι των Strmos και Cesinovo έχουν τις ιδιότητες αυτές γίνονται μια σειρά από αναλύσεις και μεθόδους. Για τη μελέτη των Τόφφων πραγματοποιήθηκε η μέθοδος περίθλασης ακτίνων Χ (XRD), η μέθοδος φθορισμού ακτίνων Χ (XRF), η μελέτη μορφολογικών χαρακτηριστικών με το ηλεκτρονικό μικροσκόπιο σάρωσης (SEM) και η θερμοβαρυτική ανάλυση (TGA). Τέλος παράχθηκαν δοκίμια τσιμέντου, όπου οι τόφφοι χρησιμοποιήθηκαν ως ποζολάνη και μελετήθηκε η ειδική επιφάνεια, η πήξη (αρχή και τέλος), οι αντοχές σε θλίψη και την απαίτηση σε Η2Ο%.There are two regions in FYROM, Cesinovo and Strmos, which are located in the Kletovo – Zletovo paleovolcanic area, west of Osogovo Mountain. Due to the volcanic activity in the area during the Cenozoic, tuff deposits were formed. Tuffs are volcanic rocks formed by the mixture of volcanic rocks and minerals fragments in a volcanic ash matrix. Tuffs, as volcanic materials, could be used like other natural pozzolanas in a concrete mix. Natural pozzolans have some properties that depend on their chemical and mineral composition and physical characteristics. These properties ultimately determine whether a specific pozzolan has activity or not. To determine if the tuffs from Cesinovo and Strmos have these properties, a variety of methods were used. In the present study, X-ray diffraction (XRD), X-ray fluorescence (XRF), morphological study with SEM and thermogravimetric analysis (TGA), were implemented. Finally, lab cements were produced with the tuffs used as pozzolanas and Blaine (fineness), setting time (initial and final), compressive strength and water demand were measured

Flash Flood Susceptibility Evaluation in Human-Affected Areas Using Geomorphological Methods—The Case of 9 August 2020, Euboea, Greece. A GIS-Based Approach.

Flash floods occur almost exclusively in small basins, and they are common in small Mediterranean catchments. They pose one of the most common natural disasters, as well as one of the most devastating. Such was the case of the recent flood in Euboea island, in Greece, in August 2020. A field survey was accomplished after the 2020 flash floods in order to record the main impacts of the event and identify the geomorphological and man-made causes. The flash flood susceptibility in the urbanized alluvial fans was further assessed using a Geographic Information System (GIS)-based approach. Our findings suggest that a large portion of the alluvial fans of Politika, Poros and Mantania streams are mainly characterized by high and very high hazard. In fact, ~27% of the alluvial fans of Politika and Poros streams are characterized with very high susceptibility, and ~54% of Psachna area. GIS results have been confirmed by field observations after the 2020 flash flood, with significant damages noted, such as debris flows and infrastructure damages, in buildings, bridges and the road networks. In addition, even though the adopted approach may be more time-consuming in comparison to purely computational methods, it has the potential of being more accurate as it combines field observations and the effect of past flooding events

Inventory and Assessment of the Geomorphosites in Central Cyclades, Greece: The Case of Paros and Naxos Islands

The Cycladic landscape is characterized by landforms of natural beauty and rarity. Landforms resulting from differential erosion, weathering, tectonics, drainage network, sea level changes, and depositional processes can contribute to the development of geotourism in the area. This can be achieved by supporting conservation, protection and promotion of the geo-environment and nature, educating students, residents, and visitors. The aim of this work is to develop an inventory of the main geomorphosites of Paros and Naxos islands by assessing their scientific and additional values, using qualitative and quantitative criteria. Our results show that, besides the high scientific interest of the 75 geomorphosites, most are also characterized by a high ecological value and can potentially lead to a significant increase in the islands’ tourism. The results of this work aim at raise awareness on the geomorphological heritage of central Cyclades and provide a basis for their promotion, protection, and management

Inventory and Assessment of the Geomorphosites in Central Cyclades, Greece: The Case of Paros and Naxos Islands

The Cycladic landscape is characterized by landforms of natural beauty and rarity. Landforms resulting from differential erosion, weathering, tectonics, drainage network, sea level changes, and depositional processes can contribute to the development of geotourism in the area. This can be achieved by supporting conservation, protection and promotion of the geo-environment and nature, educating students, residents, and visitors. The aim of this work is to develop an inventory of the main geomorphosites of Paros and Naxos islands by assessing their scientific and additional values, using qualitative and quantitative criteria. Our results show that, besides the high scientific interest of the 75 geomorphosites, most are also characterized by a high ecological value and can potentially lead to a significant increase in the islands’ tourism. The results of this work aim at raise awareness on the geomorphological heritage of central Cyclades and provide a basis for their promotion, protection, and management

Inventory and Assessment of the Geomorphosites in Central Cyclades, Greece: The Case of Paros and Naxos Islands

The Cycladic landscape is characterized by landforms of natural beauty and rarity. Landforms resulting from differential erosion, weathering, tectonics, drainage network, sea level changes, and depositional processes can contribute to the development of geotourism in the area. This can be achieved by supporting conservation, protection and promotion of the geo-environment and nature, educating students, residents, and visitors. The aim of this work is to develop an inventory of the main geomorphosites of Paros and Naxos islands by assessing their scientific and additional values, using qualitative and quantitative criteria. Our results show that, besides the high scientific interest of the 75 geomorphosites, most are also characterized by a high ecological value and can potentially lead to a significant increase in the islands' tourism. The results of this work aim at raise awareness on the geomorphological heritage of central Cyclades and provide a basis for their promotion, protection, and management

Flash Flood Susceptibility Evaluation in Human-Affected Areas Using Geomorphological Methods—The Case of 9 August 2020, Euboea, Greece. A GIS-Based Approach

Flash floods occur almost exclusively in small basins, and they are common in small Mediterranean catchments. They pose one of the most common natural disasters, as well as one of the most devastating. Such was the case of the recent flood in Euboea island, in Greece, in August 2020. A field survey was accomplished after the 2020 flash floods in order to record the main impacts of the event and identify the geomorphological and man-made causes. The flash flood susceptibility in the urbanized alluvial fans was further assessed using a Geographic Information System (GIS)-based approach. Our findings suggest that a large portion of the alluvial fans of Politika, Poros and Mantania streams are mainly characterized by high and very high hazard. In fact, ~27% of the alluvial fans of Politika and Poros streams are characterized with very high susceptibility, and ~54% of Psachna area. GIS results have been confirmed by field observations after the 2020 flash flood, with significant damages noted, such as debris flows and infrastructure damages, in buildings, bridges and the road networks. In addition, even though the adopted approach may be more time-consuming in comparison to purely computational methods, it has the potential of being more accurate as it combines field observations and the effect of past flooding events