From the territory of present day Poland, occupied during the Roman Period by the Przeworsk Culture and the Wielbark Culture, we currently have a record on ten hoards of Roman Imperial silver coinage, 1st to 3rd century (denarii, and a single denarii-and-antoniniani hoard), which also contain one, at most, two Republican or Augustan issues. A comparison of the structure of these hoards with the hoards known from other regions of Barbaricum and the territory of the Roman Empire supports the argument that these early denarii entered the region to the north of the Carpathian range with the later coins during the Imperial period, the second to the mid-third century. Perhaps, some pre-Neronian denarii, known from single and cumulative finds recorded in the Przeworsk and Wielbark culture territory were introduced to the same area during that age.
In the recent years a tendency for design of increasingly slender structures with the use of high performance concrete has been observed. Moreover, the use of high performance concrete in tunnel structures, subject to high loads with possibility of extreme loads occurrence such as fire, has an increasing significance. Presented studies aimed at improving high performance concrete properties in high temperature conditions (close to fire conditions) by aeration process, and determining high temperature impact on the concretes features related to their durability. In this paper it has been proven that it is possible to obtain high performance concretes resistant to high temperatures, and additionally that modification of the concrete mix with aerating additive does not result in deterioration of concrete properties when subject to water impact in various form.