Presentation1 Building material. .pptx

BMCT

1. Content Sr. no Content 1.0 Definition Quarrying of Stones 1.1 Site selection factors for quarrying 1.2 Methods of quarrying 2.0 Dressing of stone 3.0 Seasoning and preservative treatment

2. Quarrying of Stones 1.0 Definition: Stones occur in the form of natural rock masses or layers on the surface. The process of extracting or taking out stones from natural rocks bed is known as Quarrying of Stones

3. 1.1 Selection of Site for Quarrying Of Stones The following factors are to be considered while selecting a quarry site: Availability of good quality stone existing over a sufficiently large area. Transportation facilities : The location of quarry site must necessarily be close to at least any one of transport network (like roadways, railways)  Availability of sufficient water for labours , machines and equipments used in quarrying operations. The site must be far from permanent structures like bridges, dams ,etc.  because  the  vibrations  due  to  blasting in the site may cause harm to them Availability of adequate drainage facilities for removing underground or surface water immediately after rain. Availability of geological data of the site.

4. 2.1 Methods of Quarrying The method used for quarrying of stones depends upon on the types of stones, its intended use and the type of its geological formation. Quarrying with hand tools Quarrying by use of channeling machines Quarrying by ballasting

5. 1. Quarrying By Using Hand Tools This method is suitable for smaller works or for soft stones.  This method of quarrying is further classified into following types: Quarrying By excavation  Quarrying By Heating Quarrying By Wedging 1.2 Methods of Quarrying

6. Quarrying By excavation  – Excavation method is suitable for soft stone buried in earth or under loose overburden. Tools used in excavation are hammer, pick axe, shovel, crow bars, chisel.

7. 2) Quarrying By Heating The top surface of rock is heated by placing wood with fuel on it. The fire will be allowed for some hours and the top surface gets heated and separates from the rock. This separated portion is removed by pick axes, crowbars etc. The stones obtained by heating will be in good shape if the rock formation contains horizontal layers at shallow depth. So, the stone obtained will be directly used for masonry works

8. 3) Quarrying By Wedging This method is applicable when the rock contains cracks or joints in it. Steel wedges or steel points are put in these cracks or fissures and hit them with hammer. Then the rock portion separates from parent rock. If natural cracks are there, then artificial holes are drilled in the rock and wedging is done.

9. 2. Quarrying by use of channeling machines Machine quarrying is done by using channeling machines which is driven by steam, compressed air or electricity. In this method, a groove is made using channeling machine around the rock and the horizontal holes are drilled underneath the block. The wedges are driven into holes. Hence, the block gets separated from its bed. Larger blocks of stones can also be obtained by this method.  Marbles ,  limestones , etc. are quarried using channeling machine.

10. Quarrying with blasting: Big size stones are converted into smaller pieces using eexplosives . The main purpose of quarrying stones by blasting is to loosen large masses of rocks and not to blow up the whole mass Explosives used are Blasting powder, Blasting cotton, Dynamite and Cordite. The operations involved are Boring, Charging, Tamping and Firing.

11. Precautions in blasting Blasting should not be carried out in late evening or early morning hours. The danger zone, an area of about 200 m radius, should be marked with red flags. First aid should be available Explosives should be stored and handled carefully.

12. 2.0 Dressing of Stones: After being quarried, stones are to be cut into suitable sizes and with suitable surfaces. This process is known as the dressing of stone. Dressing of stone can be done both manually as well as mechanically. Purposes Dressing of Stones : To give the necessary appearance for structure from stone work, To make the transport from quarry easy and economical, To suit to the requirements of stone masonry, To take advantage of local trained workers for such type of work, etc.

13. Pitched dressing • In this method, only the edges of a block are leveled skillfully by use of hammers. The surface is left in original cut . Hammer Dressing • In this method of dressing edge as well as the face are reduced to even regular surface. It has pitted appearance on the surface.Wallers hammer may be used Pitched dressing

14. Chisel Dressing • In this method straight grooves are made with the help of a chisel at all four edges. The superfluous stone from the centre is removed. Chisel drafted stones are specially used in plinths and corner of the building. Rough Tooling • The edges are first made square by using chisel and hammer. Then a series of grooves of variable width are developed over the surface of stone . Chisel Dressing

15. Punched Dressing • It is done on the stone that have been already been roughed. A series of parallel ridges aremade on the stone surface using hammer andchisel . It is also called furrowed finish. Closed picked fine tooling • This is extreme type of dressing in whichalmost every type of projecting irregularity isremoved from all four sides of stones. Itssurface is given fine finish and an appealing Polished Finish This type of finish is provided for particular types of stones such as marbles, granites, etc. Polishing can be completed by hand or by machines. Punched Dressing Polished Finish

16. The freshly quarried stones contain some amount of moisture. This is called quarry sap. The process of removing quarry sap is known as  seasoning of stones.  Generally  6 to 8 months  required for proper seasoning 3.0 SEASONING AND PRESERVATIVE TREATMENT An ideal preservative has the following properties: ( i ) It does not allow moisture to penetrate the stone surface. (ii) It does not develop objectionable colour . (iii) It hardens sufficiently so as to resist effects due to various atmospheric agents. (iv) It is easily penetrated in stone surface. (v) It is economical. (vi) It is non-corrosive and harmless. (vii) It remains effective for a long time after drying. (viii) Its application on stone surface is easy

17. Coal Tar: It is a preservative which preserve the stone surface. Linseed Oil: This preservative may be used either as raw linseed oil or boiled linseed oil. Paint: Paint on stone surface serves as a preservative. Paraffin: This preservative may be used alone or it may be dissolved in naptha and then applied on stone surface Solution of Alum and Soap: The alum and soft soap are taken in proportion of about 0.75 N and 0.50 N respectively Following are preservatives which are commonly adopted to preserve the stone