Topic : Properties and Importance of Civil Engineering Materials like Stone.

Types of Building Stone:
Building stone is obtained by taking rock from the earth and reducing it to the required shapes and sizes for construction. It is a natural, richly diverse material that can vary greatly in its chemistry, structure, physical properties, and appearance. Geologically, stone can be classiÞ ed into three types according to how it was formed:

•  Igneous rock is rock that was deposited in a molten state.
• Sedimentary rock is rock that was deposited by the action of water and wind.
• Metamorphic rock was formerly either igneous or sedimentary rock. Subsequently, its properties were transformed by heat and pressure.

For commercial purposes, ASTM C119 classiÞ es stone used in building construction into six groups: Granite, Limestone, Quartz-Based Stone, Slate, Marble, and Other.

Granite Group:
Granite is the igneous rock most commonly quarried for construction in North America. It is a mosaic of mineral crystals, principally feldspar and quartz (silica), and can be obtained in a range of colors that includes gray, black, pink, red, brown, buff, and green. Granite is nonporous, hard, strong, and durable, the most nearly permanent of building stones, suitable for use in contact with the ground or in locations where it is exposed to severe weathering. Its surface can be finished in any of a number of textures, including a mirror like polish. In North America, it is quarried chiefly in the East and the upper Midwest. Various granites are also imported from abroad, chiefly from Brazil, China, India, and Italy. Domestic granites are classified according to whether they are fine-grained, medium-
grained, or coarse-grained. Requirements for granite dimension stone are deÞ ned in ASTM C615.

Limestone Group:
Limestone is one of the two principal sedimentary rock types used in construction. It may be found in a strongly stratified form or in deposits that show little stratiÞ cation ( freestone). It is quarried throughout North America, with major quarries for large dimension stone found in Missouri and Indiana. France, Germany, Italy,
Spain, Portugal, and Croatia are major suppliers of imported limestone.

Requirements for limestone dimension:
stone are specified in ASTM C568. Limestone may be composed either of calcium carbonate (oolitic limestone) or of a mixture of calcium and magnesium carbonates (dolomitic limestone). Both types were formed long ago from the skeletons or shells of marine organisms. Colors range from almost white through gray and buff to iron oxide red. Limestone is porous and contains considerable groundwater (quarry sap) when quarried. While still saturated with quarry sap, most limestones are easy to work but are susceptible to frost damage. After seasoning in the air to evaporate the quarry sap, the stone becomes harder and is resistant tofrost damage. Some dense limestones can be polished (and may be classified as marbles), but most are produced with varying degrees of surface texture.

Quartz-Based Dimension Stone
Group
Sandstone is the second major sedimentary rock type used in building construction. Like limestone, it may be found in either a strongly stratified form or as more homogeneous freestone. Sandstone was formed in ancient times from deposits of quartz sand (silicon dioxide). Its color and physical properties vary signiÞ cantly with the material that cements the sand particles, which may consist of silica, carbonates of lime, or iron oxide. Sandstone is quarried principally in New York, Ohio, and Pennsylvania. Two of its more familiar forms are brownstone, widely used in wall construction, and bluestone, a highly stratified, durable stone especially
suitable for paving and wall copings. It is quarried in the northeastern United States. Sandstone will not accept a high polish. Requirements for quartz-based dimension stone are speciÞ ed in ASTM C616.

Slate Group:
Slate is one of the two metamorphic stone groups utilized in construction. Slate was formed from clay. It is a dense, hard stone with closely spaced planes of cleavage, along which it is easily split into sheets, making it useful for paving stones, roof shingles, and thin wall facings. It is quarried in Vermont, Virginia, New York, Pennsylvania, and parts of Canada, in a variety of colors including black, gray, purple, blue, green, and red. China and India are the largest foreign suppliers of slate to North America, with Italy, the United Kingdom, and Spain also providing signiÞ cant quantities. Requirements for slate dimension stone are speciÞ ed in ASTM C629.

Marble Group:
Marble is the second of the major metamorphic rock groups. In its true geologic form it is a recrystallized form of limestone. It is easily carved and polished and occurs in white, black, and nearly every color, often with beautiful patterns of veining. The marbles used in North America come chiefly from Alabama, Tennessee,
Vermont, Georgia, Missouri, and Canada. Marbles are also imported to this continent from all over the world, primarily from Turkey, Lebanon, Mexico, Italy, China, and France. The physical properties and appearance of marble vary greatly, depending on the chemistry of the original limestone from which it was formed and, even more so, on the processes by which it was metamorphosed. Requirements for marble dimension stone are specified in ASTM C503.

Other Group:
The ASTM C119 Other Group includes a variety of less frequently used building stones. Travertine is a relatively rare, partially crystallized, and richly patterned calcite (having a chemistry similar to that of limestone) rock deposited by ancient springs. It is marblelike in its physical qualities. Requirements for travertine dimension stone are speciÞ ed in ASTM C1527. Also included in the ASTM C119 Other Group are alabaster, greenstone, schist, serpentine, and soapstone.

Quarrying and Milling of Stone:
The construction industry uses stone in many different forms. Fieldstone is rough building stone obtained from riverbeds and rock-strewn point. Rubble consists of irregular quarried fragments that have at least one good face to expose in a wall. Dimension stone is stone that has been quarried and cut into rectangular form; large slabs are often referred to as cut stone, and small rectangular blocks are called ashlar. Flagstone consists of thin slabs of stone, either rectangular or irregular in outline, that are used for flooring and paving. Crushed and broken stone are useful in site work as base layers under concrete slabs and pavings, as surfacing materials, and as aggregates in concrete and asphalt. Stone dust and powder are used by landscapers for walks, drives, and mulch.

Explore our website for more engineering related Study Material Visit Now