5 Compaction of different soils

Question 19 One of these compaction plots, for the same soil, is the result of HEAVY compaction and the other of LIGHT compaction. So, with HEAVIER compaction:
	curve A would be produced	True          False
	a higher maximum dry density results	True          False
	the optimum water content is increased	True          False
	the minimum air content is increased	True          False

Question 20 The soil types typically represented here are:
	A is a well-graded sand	True          False
	C is a clay of high plasticity	True          False
	D is a clay of low plasticity	True          False
	B is a uniform sand	True          False
	E is a sandy clay	True          False

Question 21 At increasing water contents well over the optimum value, what happens to the air content, especially in fine soils?
	it increases slowly it decreases rapidly it stays almost the same

Question 22 Both grading and plasticity affect the degree of compaction. So, a HIGHER compacted density can be achieved with:
	well-graded coarse soils	True          False
	fine soils of low plasticity	True          False
	soils with a high clay content	True          False
	fine soils in general	True          False

Question 23 It is more difficult to reduce the air content in uniform fine sands, than in well-graded soils. This is thought to be due to:
	compactive energy absorbed by pore pressure changes	True          False
	grains being moved around, but not closer together	True          False
	water 'sticking' to the grains & holding them apart	True          False
	large air-pockets forming which cannot be compressed	True          False