Whether the principles of fresh consideration for a exisiting duty is affirmation?

i really don't have a clue, but i would want to know

If the following elements exist, the defendant's promise is legally binding:

(1) A has entered into a contract with B, and

(2) before A has completely performed, B has reason to doubt that A will complete performance, and

(3) B thereupon promises A additional payment in order to ensure performance on time, and

(4) as a result of giving his promise B obtains a practical benefit, and

(5) B's promise is not given as a result of economic "duress" or "fraud "on the part of A, and

(6) the benefit to B is consideration.

If the renegotiation involves duress or fraud, there is no new consideration.