Clays Flashcards
what are the engineering problems with clays?
Clays expand putting unwanted forces on structures, enough to crack and lift foundations or floor slabs. Shrinkage can cause water/gas pipes to burst.
what are the engineering solutions to prevent damage caused by clays? x4
deep foundations or piles
adding chemicals to reduce swelling potential
lower the water table by pumping out water
irrigate the area maintaining a stable high water table
what rock is the most common source of kaolinite in Great Britain?
granite
how are clays formed?
by the weathering of crystalline rocks
Describe the structure of clays
mineral sheets in layers
either 1:1 layer or 2:1 layers
give an example of a group of clay with a 1:1 layer type
kaolin-serpentine
give an example of a group of clays with a 2:1 layer type x3
smectite
vermiculite
mica
what are the structural properties of kaolin-serpentine? x2
non-expanding
low shrink-swell capacity
what are the structural properties of smectite? x2
expanding structure
high shrink-swell capacity
what are the structural properties of vermiculite?
limited expansions
medium shrink-swell capacity
what are the structural properties of mica?
non-expanding
low shrink-swell capacity
what are the industrial uses of kaolin-serpentine? x3
ceramics and porcelain
filler for paint
paper industry to produce glossy finishes
what are the industrial uses of smectite? x6
drilling mud for oil industry protective liners catalytic processes facial powder fillers cat litter
what are the industrial uses of vermiculite? x5
fireproofing insulation packing material gardening use cat litter
what are the industrial uses of mica?
ceramic and stoneware
fillers
