Test II - Concrete 2 Flashcards
Slab On Grade
Concrete surface, lying upon, and continuously supported by, the ground beneath
Suspended or Structural Concrete Slab
Slab that spans between intermediate lines or points of support
Subgrade preparation
Site cleared, organic topsoil removed, subgrade excavated to required depth, graded level and compacted to required density
Proof Rolling
A heavy roller or loaded dump truck makes multiple passes over the subgrade
Capillary Break or Drainage Layer
crushed rock 3/4 to 1.5 in, 4-6 in deep placed over subgrade
Edge Forms
wood or metal strips are placed to contain concrete pour at slab edges; held in place by stakes of wood or metal rebar
Isolation or expansion joints
where slab abuts walls, columns, or other elements; compressible joint material is placed to create isolation or expansion joint
What can be placed over the drainage area and around the slab perimeter to reduce heat losses through the slab?
Rigid Foam Insulation
Vapor Retarder or Moisture Barrier
A heavy plastic sheet or impervious material that provides additional protection against subgrade moisture
Floating
Immediately after screeding, consolidates and smooths the slab surface
Striking off or Screeding
wood plank or metal straightedge is drawn across the surface of the freshly poured concrete, using an end-to-end sawing motion
What is a darby used for?
to float areas of the slab that can be reached without the long arm of the bull float
What is bleed water?
free water that rises to the surface when concrete dries
What are used to form well-consolidated edges and joints in the slab surface?
edgers and grooving
What does troweling provide?
a smoother finish
