1_rocks

1_rocks

1. geological classification

   • igneous rocks (molten magma) (crystalling, glossy pr fused texture)
     • granite = 70 t0 130 MN/m2,made up of felspar, quartz and mica
   • sedimentary rocks(gradual deposition)
     • lime stones = stratified rocks
   • metamorphic rocks (under pressure and extreme heat)
     • marbles = lime and silica

2. physical classfication

   • stratified rocks= distinct layers of sand
     • lime stones (sedimentary type of calcareous rock) = stratified rocks EG: kankar
     • sandstones = quartz, lime and silica, 35 to 40MN/m2
     • slate = 60 to 70 MN/m2 (form of tiles, excellant roof covering
   • unstratified rocks = can't be split, no layers
     • granite and marbles

3. chemical classification

   • silicious rock = silica EG: granite, quartzite, gneiss
   • argillaceous rocks = clay or alumina EG: SLATE, LATERITE, KAOLINE
   • calcareous rocks = lime or calcium carbonate EG: lime stone and marble

4. BRICKs = in one metre cube, 550 bricks are used, standard sizes = 19cm x 9cm x 9cm

   • manufacture of bricks
     • burning of bricks
       • done in clamp or kiln
       • takes 24 hours, 1000c to 1200c, cool down of kiln for 12 days
   • first class bricks = rect. shape, reddish color, shouldnt absorb water 20% of its own dry weight after 24 hours immersion and minimum 10.5 MN/m2
   • second class bricks = not so perfectly shaped rect, shouldn't be more than 22 % of its own dry weight
   • third clas = not fully burnt, soft and easily broken, shouldn't be more than 25%
   • over burnt bricks = bluish color