Retarders used at grouting oil wells, where temperature is about _________ oC.

Dry intervals in surface wetting leads to _______

Entrapped air normally exists in the form of relatively _____ air voids.

Chemically inactive pore fillers ______ the workability.

Chemically inactive pore fillers ________ the workability.

Which one is not chemical admixtures?

In a dry environment, concrete strength will be loosed as much as _______ % in moist environment.

What is the main function of set retarders?