masonry (stone & concrete)

commerical stone types

For commercial purposes, building stone is classified into six groups according to ASTM C199.

• Granite

• Limestone

• Quartz-based

• Slate

• Marble

• Other

  Each group has different exposure
  conditions, construction requirements

granite group

• Igneous

• Nonporous, strong, durable

• Suitable for exposure to severe weathering, ground contact

limestone group

• Sedimentary

• Strength and porosity vary with density

• Colors from white, to gray, to red

• Normally has a textured finish; a few can be polished

quartz-based group

• Sedimentary

• Sandstone: from quartz deposits

• Brownstone, and some varieties of bluestone are varieties of sandstone

slate group

• Metamorphic

• Derived from shales (mineral clays)

• Dense, hard, nonabsorbent

• Variety of colors

marble group

• Metamorphic

• Varies greatly in its physical properties and appearance

• Many colors, frequently with extensive veining

• Easily polished

other group

• Travertine:

  • Partially-crystallized, patterned calcite

  • Chemically similar to limestone

  • Similar to marble in its physical properties

other types

• Alabaster

• Greenstone

• Schist

• Serpentine

• Soapstone

quarrying

• A long-bladed diamond saw, traveling on rails, makes deep, long cuts into the solid rock.

• Closely-spaced horizontal holes are drilled into the vertical face of the rock to create a plane of weakness near the bottom of the saw cuts

• Rubber bladders are inserted into the saw kerfs and inflated, causing the large slabs to fall away from the solid rock.

• Steel wedges are driven into the separated slabs, to split them into smaller blocks

• Blocks are labeled and stacked, ready for transporting to the mill

milling

• Bandsawing & circular sawing

• Planeing

• And a variety of other shaping and surface finishing operations

• Hand carving

stone masonry

• Stone masonry: laid in mortar, self-carry all the weight of the wall

  • Rubble

  • Ashlar

• Stone cladding: mechanically fasten/attached to a separate structural frame or walls.

• Stones carry their own weight.

• Most commonly set in mortar, like brick or CMU

• Stone blocks carry own weight. CMU
  backup wall with anchors provides lateral
  support.

rubble masonry

• Unsquared stone blocks

• Random: Laid without continuous horizontal joints

• Coursed: Laid with continuous horizontal joints

ashlar masonry

• Squared blocks

• Random or coursed

stone cladding or curtain wall

• Stone panels mechanically attached to building frame

• Attachment system carries the weight of the panels

concrete masonry units (cmus)

• Stiff concrete mix pressed into metal molds

• Steam curing in autoclaves accelerates curing

• Standard nominal size: 8" x 8" x 16"

  • Actual size is 3/8-inch less in each dimension

• Can be manufactured in a great variety of shapes and sizes

dimensioning

• Like brick masonry walls, concrete masonry wall dimensions should, as much as possible, conform to the dimensional module of the block, in this case 8 inches.

  • This minimizes the need to cut block or work with small pieces

laying cmu

• Mortar is identical to that used for brick masonry

• Corner leads are laid first.

• String lines and levels are used to keep walls straight, plumb, and level

reinforcing

• Reinforcing increases compressive strength, resistance to cracking and resist to lateral forces

• Vertical steel reinforcing in a fully-grouted concrete block wall

• Specially-shaped webs to accommodate both vertical and horizontal reinforcing bars without modification

spanning openings

• Structural steel

• Steel reinforced concrete block

• Precast concrete

decorative or architectural units

• Split-face block

• Two or more blocks are cast as a single unit.

• During the curing process, the blocks are split with knife-like blades

• Ground-face block

• After curing, block surface is ground smooth, creating a polished surface.

• In any architectural block, the color of aggregates and cement can also be varied

• Glazed block

• Glass block