Types of rocks, mode of formation and Grouting

Print Friendly, PDF & Email

Rocks are classified on their mode of formation. Rock is made up of tiny particles strongly bonded together. Rock contain minerals and organic compounds.

Types of rocks:

  1. Igneous rocks: Such rocks are formed due to cooling of hot molten lava. Their look is shiny and glossy. Examples: – Granite and Basalt.
  • Sedimentary rocks: these rocks are formed by deposition of sediments of igneous rocks due to weathering process. They are layered in structure , soft and contain fossils. Examples:- Sandstone, Limestone, and Shales.
  • Metamorphic rocks: these rocks are formed when igneous or sedimentary rocks came in contact of high heat and pressure. They are hard and sometime contain crystals. Examples: Marble, Quartzite, Slate, Gneiss, and Schist.
The table given below contains some rocks which convert from sedimentary rock to metamorphic rock under high pressure and heat. These are the most important rocks, which were mainly asked in various examinations.
S.No. Sedimentary Rock( formed under high pressure) Metamorphic rock( formed under high pressure and heat)
1. Limestone convert to Marble
2. Sandstone convert to Quartzite
3. Shale convert to Slate


Grouting means the injection of stabilizers in to the soil. Grouting is mainly done under high pressure. Those stabilizers having high viscosity are permissible with soils having high permeability. Grouting method is suitable for existing building whose surrounding soil is loosing strength and pervious stratum below a dam.

Types of Grouting

Cement grouting—consists of a mixture of cement and water. Cement grouting is quite functional for stabilising rocks with fissures and coarse sand.

Clay grouting—consists of a mixture of Bentonite clay (very fine grained soil) and water and is quite functional for sandy soils

Chemical grouting—consists of a solution of sodium silicate (colloidal silicic acid and free sodium hydroxide) in water and is quite functional for medium and fine sands.

Chrome-lignin grouting—consists of two compounds i.e. hexavalent chromium and a lignosulphates and suitable for coarse silt and fine sand.

Bituminous grouting—consists of an emulsified asphalt.

Thanks for Visiting 🙂

Thanks for Visiting


Arbaj Demrot is the founder of VideRime Online Learning, a leading engineering website. He did his BE Civil and M.Tech Structure from RGPV University, Bhopal and has been working as an Assistant Professor in a reputed college.

Leave a Reply