SPECIFICITIES OF THE MASONRY TECHNIQUE OF KYIVAN MONUMENTS OF THE XTH THE BEGINNING OF THE XIITH CENTURIES

The material presented above concerns the research of the concealed course technique used in Kyivan monuments of the Xth the beginning of the XIIth centuries and its origin. The concealed course technique presents the brickwork where the alternating brick courses are slightly recessed from the wall and covered by mortar, as a result, joints appear to be much thicker than they actually are. The earliest known monument where the concealed course technique that occurs in the Desyatynna church in Kyiv completed in 996, as well as the two palaces of the Xth c. nearby. The recessed brick technique is also used in Kyivan monuments of the XIth the beginning of the XIIth centuries: the St. Sophia Cathedral, the Golden Gate, St. George’s Church, St. Michael’s Church of Vydubytsky Monastery, the Assumption Cathedral and the Holy Trinity Gate Church of Pechersky Monastery, St.Michael’s Cathedral of the Golden Domes and some other buildings. The Church of Our Savior at Berestove, completed in the first quarter of the XIIth century is the last known Kyivan monument with the concealed course technique. The following Kyivan monuments – the Church of Our Lady Pyrohoshcha (1130’s) and the St. Cyril’s Church (1140’s) have coursed brick masonry. Apart from Kyiv the concealed course technique was used during the XIth - XIIth centuries in Chernihiv (the Cathedral of the Transfiguration), Pereyaslav (St. Michael’s Church), Novgorod (St. Sophia Cathedral and St. George’s Cathedral of St. George’s Monastery) and Polotsk (St. Sophia Cathedral). Bricks used in Kyivan monuments have their side dimensions 27 to 36 cm with prevailed dimensions 27 to 36 cm. The thickness of bricks increased from 2.5 – 3 cm at the end of the Xth – the beginning of the XIth centuries to 3.5 – 4.5 cm at the end of the XIth – the beginning of the XIIth centuries. The width of mortar strips between protruding brick courses varies from 9 to 12 cm. Walls in ancient Kyivan monuments were 1.1 to 1.3 meter thick. After the edifice was erected its outside and inside walls were covered with fine lime-and-ceramic plaster. Brunov was the first scholar who noticed peculiar masonry technique used in Kyivan and several Byzantine monuments. He considered the concealed course technique first appeared in ancient Kyiv and then was adopted at Constantinople. Some other scholars (e.g. P. Rappoport and P. Vocotopoulos) agree that the technique is of Constantinopolitan origin in spite of the absence of the monuments built in concealed course technique, dating to the Xth c. The fact that no early dated examples have been found at Constantinople should be attributed to the lack of monuments to be dated between 920s, when the Myrelaion Church was erected and the middle of the XIth century when the monastery of St.George at Mangana was founded. The oldest dated example of the concealed course technique known up to now in Constantinople is substructure of the St. George’s Church at Mangana. The other monument with the concealed course technique is the Panaghia Chalkeon Church in Salonika, dated by 1028 and is consequently earlier by approximately twenty years than the earliest dated examples of the technique in Constantinople. A lot of Byzantine monuments with the recessed brickwork dating back to the XIth – the XIIIth centuries could be found at Greece and Balkans. It is obvious that the concealed course technique originated in Byzantium as a result of development of Roman concrete facing of coursed brick. The technique was widely used in Byzantine provinces where brick was prevailing building material. Evidently the technique was developed already at the Xth century or even earlier, before it was adopted by ancient Kyivan builders. It appeared that concealed course technique could not be undoubtedly considered the hallmark of Constantinople but a widely spread medieval building practice.

Challenge for Next Generation of Concrete Bridges, Non-Metallic Bridge with Zero Cement Concrete

Concrete engineers and researchers have been developed durable reinforce concrete technologies for long time. However, we have not reached the goal which gives us a perfect technology against deterioration of reinforced concrete. Basically concrete itself is high durable material. And we recognize this fact when we see Roman concrete structures are still working now. The technologies described in this paper are the challenge to derive the solution against deterioration of reinforced concrete. This research and development has been taking for about 30 years. Then a non-metallic highway bridge is under design and will be built in 2020 with the key technologies of aramid fiber tendons, fiber reinforced concrete and butterfly web.

Materials Data Science for Microstructural Characterization of Archaeological Concrete

ABSTRACTAncient Roman concrete presents exceptional durability, low-carbon footprint, and interlocking minerals that add cohesion to the final composition. Understanding of the structural characteristics of these materials using X-ray tomography (XRT) is of paramount importance in the process of designing future materials with similar complex heterogeneous structures. We introduce Materials Data Science algorithms centered on image analysis of XRT that support inspection and quantification of microstructure from ancient Roman concrete samples. By using XRT imaging, we access properties of two concrete samples in terms of three different material phases as well as estimation of materials fraction, visualization of the porous network and density gradients. These samples present remarkable durability in comparison with the concrete using Portland cement and nonreactive aggregates. Internal structures and respective organization might be the key to construction durability as these samples come from ocean-submersed archeological findings dated from about two thousand years ago. These are preliminary results that highlight the advantages of using non-destructive 3D XRT combined with computer vision and machine learning methods for systematic characterization of complex and irreproducible materials such as archeological samples. One significant impact of this work is the ability to reduce the amount of data for several computations to be held at minimalistic computational infrastructure, near real-time, and potentially during beamtime while materials scientists are still at the imaging facilities.

PONS ARCIS VS COLUMNAE TRAJANI

The article highlights the results of the research of the Castle Bridge in Kamianets-Podilsky, which allowed to deepen the chronology of the bridge’s appearance back to the first centuries AD ‒ the age of Trajan’s Wars, and to insert the Castle Bridge into the context of fortification construction represented by the remains of the defense structures of the first centuries AD that were discovered in Kamianets-Podilsky in 1970 ‒1990. The search of architectural and construction analogues of the bridge has led to the reliefs depicted on the Trajan’s Column in Rome (113 AD), the analysis of which allowed, in its turn, to rebut the generally accepted by the world science attribution of one of the column’s reliefs (XCIX) as the depiction of the Bridge over Danube, constructed in 103‒105 by Apollodorus of Damascus during the Dacian Wars. The author suggest a new attribution of the image of this bridge on Trajan’s Column, interpreting one of the well-known reliefs as the depiction of the bridge (LXXXVI). She argues in favor of the fact that the Bridge over Danube was completely made of stone and had no wooden arches. It became the first attempt of Apollodorus of Damascus, the author of the dome of Pantheon in Rome, to apply the Roman concrete in arches on large-scale constructions. Using the reliefs of the column as analogy allowed the author to reconstruct the image of the bridge in Kamyanets-Podilsky for the period of the first centuries AD. The conducted researches also give grounds to consider the Middle Dniester region as a contact zone on the border of early-Slavic and late-Antique worlds.