Jiri Witzany

THE ANALYSIS OF NON‐STRESS EFFECTS ON HISTORICAL STONE BRIDGE STRUCTURES (MONITORING, THEORETICAL ANALYSIS, MAINTENANCE)

Abstract Due to non‐stress cyclic effects of temperature and moisture, stone bridge structures are subjected to deformations, a gradual growth of permanent deformations, crack development and subsequent disintegration of the stone masonry of bridge vaults. A theoretical analysis of the stress‐state and deformations of the stone bridge structure caused by non‐stress effects and the in‐situ monitoring of deformation changes of the breast walls and the bridge vaults of the historic structure of Charles Bridge (from the mid‐14th century) manifested a response and a growth in permanent deformations and disintegration of the stone bridge structure due to the effects of temperature and moisture. The behaviour of the bridge structure is significantly affected by the interaction of the vault bridge structure with the bridge body filler when exposed to the above‐mentioned non‐stress effects. Special attention must be paid to the spacing effect of filling layers on the stone bridge structure. When repairing historic...

Strengthening of Masonry Structures Using FRP — Experimental Research

The article deals with the problems of the failure mechanism and the load-bearing capacity of masonry barrel vault structures and masonry columns strengthened with fabric of carbon fibres. The executed experimental research of the effect of strengthening segmental barrel vaults and masonry columns by carbon fabric showed a prominent growth in the ultimate bearing capacity and ductility of barrel vault structures and masonry columns. The application of carbon fabric (CFRP) in the vault area exposed to tensile stresses limited not only the appearance and development of characteristic tensile cracks at these vault cross-sections, but also significantly increased the vault stability against buckling. The position of strengthening elements — the carbon fabric (CFRP) — affected the failure mechanism of the masonry vaults and masonry columns.