Placing and Finishing Tools and Equipment Chapter 6 Starts on CCS1-10 page 33

Chapter Topics Spreading tools Consolidation or vibrating tools Laser-guided screeds Hand screeding tools Tools for smoothing after screeding Jointing and edging tools Hand floats and trowels Power floats and trowels Power saws

Spreading Tools Amount of hand work needed depends on: Concrete being placed close to the desired location Tools for hand spreading include: Short-handled, square-end shovels Come-alongs Concrete rakes CCS1-10 page 33 LHS

CCS1-10 page 33 RHS

Consolidating or Vibrating Tools Consolidation removes the entrapped air, producing concrete with the properties normally expected and desired for concrete slabs. Equipment for consolidation of slabs: Internal vibrators Surface vibrators Vibrating screeds Vibratory roller screeds Laser-guided screeds CCS1-10 page 33 LHS

CCS1-10 page 33 RHS

CCS1-10 page 33 RHS

CCS1-10 page 34

Hand Screeding Tools Screeding or strikeoff is sometimes done manually with a straightedge consisting of a rigid, straight piece of wood or metal. Several types of manually operated straightedges including hollow magnesium straightedges made especially for screeding. Short straightedges are usually made of either wood or magnesium, whereas longer ones are made of steel angles or channels. Some straightedges are built in such a way that they can be adjusted to provide a crown (or camber) to the surface. CCS1-10 page 34 LHS

Tools for Smoothing After Screeding Bullfloats used for FF 20 or less handle with large piece of wood or metal attached Highway straightedges used for FF greater than 20 6 to 12 ft long rectangular metal straightedge Darbies long, hand-held floats used in congested areas CCS1-10 page 34 LHS and RHS and page 35 LHS

CCS1-10 page 34 RHS

CCS1-10 page 35

CCS1-10 page 35 RHS

Jointing and Edging Tools Edgers Make neat round edges less likely to chip or spall. Various hand-held sizes and shapes; walk-behind. Jointers (Groovers) A cutting edge that makes a narrow groove. The groove (contraction joint) produces a weakened section that helps cracks appear below the neat, straight joints. Groove depth should be ¼ slab thickness. CCS1-10 page 35 LHS and RHS

CCS1-10 page 36 LHS

CCS1-10 page 36 LHS

Hand Floats Used to remove small imperfections and produce a level, plane surface and prepare surface for troweling Type of hand floats Wood Magnesium Composition Wood used for non-air-entrained and high-slump concrete. Magnesium used for air-entrained and lightweight concrete. CCS1-10 page 35 RHS and page 36 RHS

Hand Trowels Used in final stages of finishing, after floating, to create hard and dense surface. As surface hardens, subsequent trowelings are done with smaller trowels to increase pressure on surface. Fresnos are large, long-handled trowels used to smooth the slab quickly but does not provide a hard, dense surface. CCS1-10 page 36 RHS and page 37 LHS

CCS1-10 page 36 LHS

CCS1-10 page 36 RHS

CCS1-10 page 37 LHS

Power Floats and Trowels Machines Walk-behind (3 ft to 4 ft ring diameter) Riders (6 ft to 10 ft wide) Blades/attachments Float blades or shoes: wider than trowel blades Trowel blades: narrowest blades Combination blades: for floating and troweling Pans: circular disks attached blades CCS1-10 page 37 LHS and RHS

CCS1-10 page 37 RHS

CCS1-10 page 37 RHS

Power Saws Dry-cut and wet-cut saws with an abrasive or diamond blade to cut contraction joints in large concrete surfaces. Dry-cut saws Lighter than wet-cut saws Permit joint sawing within 1 to 4 hours after finishing Wet-cut saws Can cut deeper joints Joints sawed later than 4 hours after finishing CCS1-10 page 38 RHS

End of Chapter 6