Attività

  • lyy150b15 ha inviato un aggiornamento 2 anni, 10 mesi fa

    A NONELASTIC RUBBER STRIP DRAIN

    The use of doubled strips of rubber dam material for drains has become general in this clinic, especially for wounds that do not require irrigation. These have been found superior to tubing and the ordinary type of cigaret wicks because they are nonirritating to the wound and the capacity of the drain is increased as a result of the capillarity derived from the two opposed surfaces of the rubber dam material. On removal, these drains leave very little deformity in the tissue and they do not tend to plug the wound, as do wick or tube drains frequently.

    This type of material has the fault of stretching considerably and of sometimes breaking, a portion being left within the wound. To obviate this we have strengthened strips of rubber dam material by running a seam down the center with a sewing machine. This makes the rubber nonelastic and adds sufficiently to its tensile

    The proper assembly of underground precast concrete structures is often critical in the construction of underground structures. In particular, interfacial waterproofing between precast concrete segments is a key factor influencing use, safety, and life span. Current practice is to incorporate waterproofing rubber strips in the design. During the installation process, compressive stress is applied to the strip by post-tensioning to achieve performance. For this paper, lateral constraint compression tests were carried out on composite rubber seal strips that utilize putty. Special waterproofing and sealing test devices were designed to investigate corresponding relationships between water pressure and compressive stress (or strain). A relationship between water resistance pressure and compression stress and strain of the putty-based composite rubber strip was proposed based on the series tests and the control target of the minimum compression strain of the putty composite rubber strip was then suggested. Finally, full-scale waterproofing tests on tunnel joints were conducted. The experimental results provide a scientific reference for the engineering application and design of composite sealing rubber strips putty for underground post-tensioned precast concrete structures.