Abstract

refabrication in infrastructural development with a focus on airport construction and its necessity for the project's short duration. The technology of precast panels is explained in the first part of the thesis including the specifics of different areas (structures) of the airports and their various needs. A comparison between precast and cast-in-place methods is performed regarding the construction time and financial aspects. Case study of the planned expansion and a hypothetical reconstruction at the Barcelona El Prat airport is analyzed and consequent conclusions and recommendations are made. Incoming

Abstract

Workability of concrete varies during pumping. Even though concrete satisfies the required workability before pumping, it often does not satisfy the required standard after pumping. Moreover, serious problem could happen such as segregation and blockage. In this study, the rheological properties of concrete change during pumping from the pressure distribution over the pipe length was investigated. The rheological properties and the pressures measured from seven different real-scale pumping tests with 116 m to 1000 m long pipelines and 24 MPa to 100 MPa concrete were analyzed. As a result, it was found that the rheological properties vary gradually along the pipeline, and could abruptly change inside the pump. The variation of rheological properties during pumping seems to be attributed in part to the increase of water absorption in aggregates under high pressure and the additional mixing effect, namely, intensive shearing under high pressure inside pump. Document type: Article