The function of the compound waterproofing agent is actually to fill the gaps in the concrete, thereby making the concrete waterproof. Alum has a waterproofing effect. Alum is a compound salt that plays the role of an “early strength agent” in concrete admixtures. That is to say, adding an appropriate amount of alum can shorten the time it takes for the concrete to harden to a certain strength. Alum is a compound salt that plays the role of an “early strength agent” in concrete admixtures. That is to say, adding an appropriate amount of alum can shorten the time it takes for the concrete to harden to a certain strength.
