building stones

Department of Civil EngineeringIqra National University Peshawar

BUILDING STONES

Civil Engineering Materials (CE-116)

Lecture 4

Engr .Muhammad Farhan Khattak

Building Stones2

Building Stone

• Stone: A construction material derived from rocks in the earth’s crust and mixture of two or more minerals.

• Mineral is a substance which is formed by the natural inorganic process and possesses a definite chemical composition and molecular structure.

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Building Stones

• Stones used in most historical places– Pyramids of Egypt– Taj Mahal of Agra, India– Great wall of China– Greek and Roman structures– Quaid’s tomb in Karachi– Shahi mosque in Lahore– Forts at Rohtas, Lahore– Lloyd’s Barrage at Sukkur

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History

Taj Mehal ??

The Great Pyramids

??

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Civil Engineering Uses• Construction of residential and public buildings• Construction of dams, weirs, harbors, bridge

abutments, etc• Face work of structures for appearance and

ornamental value• Road metal and railway ballast• Aggregate for concrete• Stone dust as substitute for sand• Thin slabs for roofing, flooring and pavements• Limestone for manufacture of lime, cement, etc

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Building Stones

• Stone as building material lost its importance due to– Advent of cement and steel – – Structural strength can not be rationally

analyzed– Transportation difficulties– Dressing problems

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Stone Balast

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Classification of Rocks

Rocks

Geological Physical Chemical

Igneous

Sedimentary

Metamorphic

Stratified

Un-Stratified

Foliated

Argillaceous

Siliceous

Calcareous

Practical

Granite,Basalts

Marble

Limestone,Sandstone,

Slate

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Classification of Rocks• Geological classification

– Igneous rocks (primary, un-stratified, eruptive) – cooled down molten volcanic lava (magma). Basalts and granites.

– Sedimentary rocks (aqueous, stratified) – gradually deposited disintegrated rocks. Sand stones and lime stones

– Metamorphic rocks – transformed due to great heat and pressure. lime stone to marble, shale to slate(Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments (silt-sized particles) of other

minerals, especially quartz)

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Igneous Rock

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Sedimentary Rocks

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Metamorphic Rocks

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• Physical classification– Stratified rocks – separable distinct layers.

Cleavage(Cleavage is the tendency of crystalline materials to split

along definite crystallographic structural planes) plane of split visible. Slate, sandstone, lime stone

– Un-stratified rocks – no sign of strata, cannot be easily split into slabs. Granite, basalt, trap

– Foliated rocks – having tendency to split up only in a definite direction

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Stratified Rocks

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Un-stratified Rocks

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Foliated Rocks

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• Chemical Classification– Siliceous rocks – containing silica SiO2 (sand)

and silicates. Granite, basalt, quartzite, etc– Argillaceous rocks – containing clay or

alumina Al2O3. Slate, laterite, etc– Calcareous rocks – containing calcium

carbonate or lime. Limestone, marble, etc

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Characteristics of GoodBuilding Stones

• Appearance & color – uniform color, lighter shades preferred, free from clay holes, bands or spots

• Structure – Not dull in appearance, crystalline homogenous close grained is good, stratification should not be visible.

• Weight – heavier are compact, less porous, good for hydraulic structures

• Strength – generally compressive strength needed, igneous rock stones are stronger

• Hardness– resistance to abrasion, friction and wear. Hardness scale 1 to 10

• Toughness – Withstand impact, vibrations, moving loads• Dressing – uniform texture and softness for fine surface

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Characteristics of GoodBuilding Stones

• Porosity and Absorption – exposed surface absorbs rain water forming acids causing crumbling action. Cyclic freezing and thawing of pore water

• Seasoning – hardening and weathering affect due to evaporation of quarry sap and formation of crystalline film. 6 to 12 months for proper seasoning

• Weathering – resistance to action of weather• Resistance to fire – free from calcium carbonate or

oxides of iron• Durability – compact, homogenous and less absorptive

is more durable• Cost – quarrying, transportation, dressing and

installation

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Quarrying of Stones

Quarrying and Dressing

• Quarrying: An art of extracting stones from the rock beds of different varieties used for general building work and broken stones for roads and concrete work, etc

• Quarry: The place from which stone is obtained by digging or blasting etc

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Selection of Stones• Heavy engineering works bridges, piers, abutments,

break waters, docks, light houses – granite • Buildings facing the sea – granite, fine grained

sandstone• Buildings in industrial area – granite, compact sandstone• Arches – fine grained sandstone• Building face work – marble, close grained sandstone• Fire resisting structure – compact sandstone• Road metal and aggregate for concrete – granite, basalt,

quartzite• Railway ballast – coarse grained sandstone, quartzite• Electrical switch board – slate, marble

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