OK. I did quick Google search, and looked at the ingredients list for the first dough conditioner I found. I will paste it below:
Ingredients: Wheat Flour, Mono-Diglycerides, Calcium Sulfate, Dextrose, Tricalcium Phosphate, Ascorbic Acid, Salt, L-Cysteine, & Enzymes.
I don't see cement or wallboard listed.
Calcium sulfate is gypsum is wallboard.