Classification of rocks

Learn : Classification of rocks,Geological classification of rocks, Physical classification of rocks, Chemical classification of rocks CLASSIFICATION OF ROCKS Stones are obtained from rocks. A rock forms portion of earth's crust having no definite shape or chemical composition. It is usually a mixture of two or more minerals and is not homogeneous.             Rocks from which stones can be found for building purposes are classified in the following three different ways: (i)        Geographically (depending upon how the rock was originally formed). (ii)       Physically (depending upon what its structure is). (iii)     Chemically (depending upon its chemical composition). Geological classification of rocks : Geologists classify rocks into three main categories: (i)        Igneous, primary, unstratified or eruptive rocks. Inner layers of earth are at such high temperatures that masses of silicates melt. This molten mass, known as magma, is forced up. Magma solidifies into rocks when it reaches the surface of earth and…

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Building stones

Learn : Stones, Building stones,causes - Stone are gradually losing their universal use as a building materials, Uses - Stones are extensively used STONES Stone is a natural material of construction and is obtained from quarries. Since prehistoric days it has been used for constructing different components of buildings like foundations, walls, lintels, floors, roof etc. It has also been used for constructing bridges, wires, dams etc. Stones that are used for construction of structures are known as building stones. Most of the ancient temples and forts of India were built with stones. The Taj and the Victoria Memorial (Calcutta) were built in white marble had from Rajasthan. Red Fort and Jama Maszid (Delhi) were built with red sand stone from Agra. Parliament House, Rashtrapati Bhawan and the Central Secretariat (Delhi) were built with red and grey sand stones from Rajasthan.             Stone are gradually losing their universal use as…

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Plane Truss and Geometric stability and static determinacy of trusses

Truss A truss is an articulated structure composed of straight members arranged and connected in such a way that they transmit primarily axial force. If all the members lie in one plane it is called a plane truss. A three-dimensional truss is called a space truss.  PLANE TRUSS                                                                        The basic form of a truss is a triangle formed by three members joined together at their common ends forming three joints. Such a triangle is clearly rigid. Another two members connected to two of the joints with their far ends connected to form another joint forms a stable system of two triangles. If the whole structure is built up in this way it must be internally rigid. Such a truss if supported suitably will be stable. For example, The truss has to be supported in general by three reaction components, all of which are neither parallel nor concurrent. Such a truss…

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