Air entrainment with polyoxyalkylene copolymers for concrete treated with oxyalkylene SRA

A composition for entraining air in a hydraulic cementitious composition having an oxyalkylene shrinkage reduction admixture, comprising:

• a polyoxyalkylene copolymer having a molecular weight of at least 1000 or greater, said copolymer having a di-block structure
• R1—[OA1]m—[OA2]n—OR2;
• or
• R1—[OA2]n—[OA1]m—OR2
• wherein R1 and R2 represent hydrogen, an alkyl group, a cyclo alkyl group, or an aryl group;
• OA1 represents an oxyalkylene group wherein O represents oxygen and A1 represents ethylene groups;
• and OA2 represents an oxyalkylene group wherein O represents oxygen and A2 represents propylene groups, butylene groups, or mixture thereof;
• m is an integer of 5-200;
• and n is an integer of 5-200;
• said composition further comprising at least one air entraining agent selected from the group consisting of a polyoxyalkylene polymer having a molecular weight less than 1000, a tall oil, a vinsol resin, a fatty alkanolamides, an ethoxylated fatty amine, ethoxylated fatty acid, ethoxylated triglyceride, ethoxylated alkylphenol, ethoxylated alcohol, alkyl ethoxylate, alkylaryl ethoxylate, a cationic air entraining agent, amphoteric air entraining agent, and anionic air entraining agent.

A cementitious composition comprising:

• a cement binder;
• at least one oxyalkylene shrinkage reduction admixture;
• a water soluble salt;
• and a polyoxyalkylene copolymer having a molecular weight of at least 1000 or greater, said copolymer having a di-block structure
• R1—[OA1]m—[OA2]n—OR2;
• or
• R1—[OA2]n—[OA1]m—OR2
• wherein R1 and R2 represent hydrogen, an alkyl group, a cyclo alkyl group, or an aryl group;
• OA1 represents an oxyalkylene group wherein O represents oxygen and A1 represents ethylene groups;
• and OA2 represents an oxyalkylene group wherein O represents oxygen and A2 represents propylene groups, butylene groups, or mixture thereof;
• m is an integer of 5-200;
• and n is an integer of 5-200;
• said shrinkage reduction admixture and said salt being present in the cementitious composition in the amount of 0.1-10% s/s based on the weight of cement in the composition, and said polyoxyalkylene copolymer being present in the cementitious composition in the amount of 0.005-5.0% s/s based on the weight of cement in the composition.