Chapter 9 Chapter 9 Stone & Concrete Masonry
Stone compared to Brick • Similarities: • Both stacked • Mortar Joints • Differences: • Shape: • Brick molded - Stone Cut and Carved • Brick made/controlled – Stone provided by nature but shape may be altered.
Three Types of Building Stone • Igneous • Sedimentary • Metamorphic
IGNEOUS ROCK Is rock that was formed by the cooling and solidification of a molten mass of rock material called magma. It is very hard and strong. • SEDIMENTARY ROCK Is material that was deposited in particle state, moved by wind or water, then pressed under extreme earth pressure. • METAMORPHIC ROCK Is material that used to be something else. Its original composition and texture has been altered by heat and pressure deep within the earth’s crust.
GRANITE is the major type of igneous rock that is prevalent in construction. The best example of granite used in Texas is the State Capital in Austin. • SHALE, LIMESTONE, and SANDSTONE are examples of natural sedimentary rock. Most is relatively light in color, gray to white, and can be cut into relatively thin sheets for building veneer. Texas shell stone is an unusual example of sandstone rock. • SLATE and MARBLE are the best examples of metamorphic rock. Colors are in a wide range from light to black. Slate can be cut thin enough to make roofing shingles. Marble is durable and hard and can be polished to a mirror surface finish, but is relatively porous.
Polished Surface Rough Texture
Texture Variances (Note the Effect on Appearance)
Shape Flat to Round
Sedimentary RockLimestone & Sandstone • Porous, relatively weak by comparison • Color Range – doesn’t have much character • Surface Textures – does not take fine polish • Sources – mid west region of U.S. • Primary Uses – primarily veneer facing on building exteriors.
Simulated Limestone Cladding Actually is pre-cast concrete finished to look Like limestone – very durable
Metamorphic Rock Marble Slate
Types of Building Stone • Fieldstone • Rubble Stone • Dimension Stone
Stone Masonry Patterns Laid in Mortar • Rubble has irregular shapes and sizes. Large pieces are laid at random will fill of smaller stones. • Ashlar pattern has relatively square and rectangular pieces.
Stone Masonry • Rubble stone and ashlar pattern stone is laid in mortar beds much like brick. Stone may be laid to form the structural mass of wall, or it may be installed in a single facing layer to become a veneer attached to some other structural support. • Cut stone such as marble, granite, and sandstone are mechanically fastened in large sheets to a support system and fastened in place with steel cramps. Joints may be filled masonry grout.
Concrete Masonry Units • Concrete masonry units are made of concrete, except for modifications in the materials. Aggregates in masonry units are made of lighter weight material such as expanded shale rather than hard rock. • The units are cast in steel molds then placed in a controlled atmosphere where the cement is allowed to cure to the full strength of the mix. • Units are made in a variety of shapes and sizes for specific applications.
Bond Beam Typical Shape Combination ‘Corner’ – Round & Square
Spanning Openings in Concrete Masonry Walls • Steel Lintels • Block Lintels - Reinforced Bond Beam • Pre cast Reinforced Concrete Lintel
Decorative CMUs Split face CMU