Question

	a.	AEA will retard setting times due to entraining air
	b.	Ac will accelerate setting times to allow a delay in finishing operations
	c.	WR will not change setting times due to lowering w/c
	d.	Re will retard setting times to allow a delay in finishing operations

Answer 1

a)A is correct, as air entraining admixtures improve workability as air works as lubricants between particles. Therefore we get more time until the concrete sets.

b) false, Accelerators accelerate the process of hydration of cement so it doesn't allow the delay in finishing process but when we can't afford delay in finishing, we use accelerators.

c) false, water reducers also knows as retarders in some cases are used for the purpose of reducing the w/c ratio which in turn increases the strength of cement or concrete as per Abram's law. They do change setting time.

d) correct, retarders increase the setting times, therefore allows us delay in finishing process.