Suchergebnisse

The paper presents the issue of layer thickness selection in designing of concrete airport pavements
depending on the values of soil substrate calculation parameters. This analysis is based on laboratory
testing of low-frost-susceptible soils, specifically silty sands of various silt content, for which the California
Bearing Ratio values were determined [1, 2]. Dimensioning methods used in airport pavement design
are presented, together with their brief descriptions. Comparative calculations of surface layer thickness
depending on the interpretation of the obtained CBR laboratory test results are performed. Differences
in airport pavement layer thickness resulting from the assumed CBR values are presented. A correction
of the results of pavement calculations based on the California bearing ratio is proposed.
Keywords: airport pavement, CBR test, pavement dimensioning, soil subtrate, low-frost-susceptible soil.

The paper presents the concept of a protective structure in the form of a prefabricated reinforced concrete protective dome intended for protection of a single critical infrastructure facility [1]. Unlike non-movable cast-in-place reinforced concrete structures, the protective structure can be assembled and disassembled repeatedly with the use of dedicated joining sockets. To provide the concept with a high mobility, the dimensions of single modules of the prefabricated reinforced concrete protective dome meet the transport limits dictated by the horizontal and vertical clearance of roads. A numerical computational analysis facilitated a determination of the distribution of internal forces in the protective stricture and dimensioning of the required reinforcement system [3]. The computations included standardized cases of steady and dynamic loads, and combinations thereof, complete with parameters of dynamic loads from an explosion impulse.
Keywords: building engineering, protective structure, prefabricated dome

The paper presents a performance characteristics of a pneumatic launcher, which is an important element of the split Hopkinson bar set-up (SHPB) at the Department of Military Engineering and Infrastructure (the Military University of Technology in Warsaw) for the purpose of dynamic strength tests of construction materials. The process of experimental calibration of the launcher for selected loading bar-projectiles is shown. Two types of compression during direct impact tests were also used simultaneously to investigate the behaviour of metallic samples with the use of this launcher as well as the Hopkinson measuring bar: the first — a short cylindrical sample, including a miniature (small diameter) sample, and the second — a long cylindrical sample (Taylor test). The relationships describing the stress and strain state as a function of strain rate for the first type of the experiment and engineering empirical formulas for the second type of the research were given.

The paper presents a performance characteristics of a pneumatic launcher, which is an important element of the split Hopkinson bar set-up (SHPB) at the Department of Military Engineering and Infrastructure (the Military University of Technology in Warsaw) for the purpose of dynamic strength tests of construction materials. The process of experimental calibration of the launcher for selected loading bar-projectiles is shown. Two types of compression during direct impact tests were also used simultaneously to investigate the behaviour of metallic samples with the use of this launcher as well as the Hopkinson measuring bar: the first — a short cylindrical sample, including a miniature (small diameter) sample, and the second — a long cylindrical sample (Taylor test). The relationships describing the stress and strain state as a function of strain rate for the first type of the experiment and engineering empirical formulas for the second type of the research were given.

The paper presents a performance characteristics of a pneumatic launcher, which is an important element of the split Hopkinson bar set-up (SHPB) at the Department of Military Engineering and Infrastructure (the Military University of Technology in Warsaw) for the purpose of dynamic strength tests of construction materials. The process of experimental calibration of the launcher for selected loading bar-projectiles is shown. Two types of compression during direct impact tests were also used simultaneously to investigate the behaviour of metallic samples with the use of this launcher as well as the Hopkinson measuring bar: the first — a short cylindrical sample, including a miniature (small diameter) sample, and the second — a long cylindrical sample (Taylor test). The relationships describing the stress and strain state as a function of strain rate for the first type of the experiment and engineering empirical formulas for the second type of the research were given.