Civil Boss

Self-Consolidating Concrete (SCC): Behavior, Tests, and Site Controls Self-consolidating concrete (SCC), also called self-compacting concrete, is proportioned to flow under its own weight, fill the formwork, pass through reinforcement, and remain sufficiently stable without mechanical vibration. The defining balance is flowability, passing ability, and resistance to segregation. A high slump by itself does not prove that concrete is SCC. How SCC is assessed Fresh-property tests are selected in the project specification or approved mix procedure. Slump-flow testing describes spread and may include a time measurement; a J-ring or equivalent passing test helps reveal blocking around reinforcement; segregation resistance is checked using an agreed method. These tests complement, rather than replace, the approved mix design, sampling plan, and acceptance criteria. Use the current adopted standard and project documents because methods and limits vary. Mixture and qualification SCC is designe...

  Geotechnical factors often exert a major influence on damage patterns and loss of life in earthquake events. For example, the localized patterns of heavy damage during the 1985 Mexico City and 1989 Loma Prieta, California, earthquakes provide grave illustrations of the importance of understanding the seismic response of deep clay deposits and loose, saturated sand deposits. The near failure of the Lower San Fernando dam in 1971 due to liquefaction of the upstream shell materials is another grave reminder that we must strive to understand the seismic response of critical earth structures. The characteristics and distribution of earth materials at a project site significantly influence the characteristics of the earthquake ground motions, and hence significantly influence the seismic response of the constructed facilities at a site. Moreover, the composition and geometry of earth structures, such as earth dams and solid waste landfills, significantly affect their seismic response. ...