Air void-forming material for cementitious systems

An air void-forming agent comprising:

• at least one air void-forming material with foaming effect,
• at least one air void-forming material with defoaming effect, and
• water,
• wherein:
• the at least one air void-forming material with foaming effect is different than the at least one air void-forming material with defoaming effect,
• the at least one air void-forming material with foaming effect and/or the at least one air void-forming material with defoaming effect includes at least one amide ethoxylate or amine ethoxylate, and
• the at least one air void-forming material with foaming effect and the at least one air void-forming material with defoaming effect are present in the air void-forming agent in amounts such that, when the air void-forming agent is mixed into a cementitious system, the air content in the cementitious system changes within 40 minutes after the end of the mixing process by not more than approximately 13% of the original air content.

An air void-forming agent comprising:

• at least one air void-forming material with foaming effect selected from the group consisting of tall oil, fatty acids, anionic surfactants, fatty alcohol sulfates, amino acid derivatives, phosphates, amphoteric compounds, alkylphenol ethoxylates, amide ethoxylates, and amine ethoxylates;
• at least one air void-forming material with defoaming effect selected from the group consisting of fatty alcohol ether sulfates, phosphates, amphoteric compounds, amide ethoxylates, and amine ethoxylates;
• and
• water,
• wherein:
• the at least one air void-forming material with foaming effect is different than the at least one air void-forming material with defoaming effect, and
• the at least one air void-forming material with foaming effect and the at least one air void-forming material with defoaming effect are present in the air void-forming agent in amounts such that, when the air void-forming agent is mixed into a cementitious system, the air content in the cementitious system increases within 40 minutes after the end of the mixing process by a non-zero amount not more than 20% of the original air content.