GLOSSARY OF TERMS
- Abut
- to put two objects against each other.
- Admixture
- chemical enhancing substance that is added to the primary mixture.
- Aggregate
- crushed stone, gravel, or other material added to cement to make concrete or mortar.
Gravel and crushed stone are considered course aggregate; sand is considered fine aggregate.
- Broom Finish
- the texture created when a concrete surface is stroked with a stiff broom while the
concrete is still curing.
- Concrete
- fresh concrete is a semi-fluid mixture of Portland cement, sand, gravel, or crushed
stone and water.
- Control Joints
- special joints, also called contraction joints, which are tooled into the surface and
make concrete crack in straight lines at planned locations.
- Creosote
- oil based preservative used to prolong the life of wood.
- Curing
- providing proper moisture to a slab to reduce cracking and shrinkage and to develop
strength.
- Darby
- a long tool used for smoothing the surface of a concrete slab.
- Edge Joints
- rounded edges of a pour that are resistant to cracking.
- Excavation
- to dig out earth or soil so that a slab will be supported by a subgrade that is hard,
uniform and well drained.
- Floating
- the process of smoothing the surface of a pour with a float made of steel, aluminum,
magnesium, or wood. This action drives the large aggregate below the surface.
- Form Work
- the forms, or molds, that contain and shape wet concrete. Forms are usually built from
lumber; plywood is used for curved sections.
- Isolation Joints
- strips in form work that separate new concrete from existing adjacent construction and
other concrete slabs that might expand and contract differently or experience different
soul settlements.
- Mortar
- a mixture of cementious materials, fine aggregate, and water. Mortar is used to bond
bricks or blocks.
- Permeability
- the ability of water to penetrate the cement.
- Portland Cement
- a mixture of burned lime, iron, silica, and alumina. This mixture is put through a
kiln and then ground into a fine powder and packaged for sale. The cement is the same
color as the gray limestone quarried near Portland, England.
- Prepackaged Concrete Mix
- a mix that combines cement, sand and gravel in the correct proportions and requires only
the addition of water to create fresh concrete.
- Porosity
- the air bubbles that are trapped in concrete which reduces its strength.
- Ready-Mixed Concrete
- wet concrete that is transported from a concrete supplier. The concrete is ready to pour.
- Reinforcing Mesh
- steel wires woven or welded into a grid of 6 - 10 inch squares. The mesh is primarily
used in flatwork, such as sidewalks, patios, and driveways.
- Screeding
- using a straight 2x4 moved from one end of a concrete pour to the other; strike off
excess concrete.
- Tamp
- compacting the subgrade with either an mechanical vibrating device or a hand held tool.