Admixtures for shrink crack reduction of portland cement-based mortars and concretes

A dry, flowable-powder consisting essentially of:

• magnesium oxide including a light calcined material calcined at temperatures ranging from approximately 750° C. to approximately 1,200° C.;
• a shrinkage reduction agent, the shrinkage reduction agent including at least one of:
• wherein each R independently includes one of a hydrogen atom and a C1 to C2 alkyl, each R′ independently includes a C1 to C2 alkyl, and n is an integer from 1 to 2;
• and
• HO(AO)xH, wherein A is one of methylene, ethylene, and propylene, and x is an integer from 1 to 1;
• and
• a super absorbent polymer including a polyacrylic and polyacrylamide copolymer.

A dry, flowable-powder consisting essentially of:

• magnesium oxide including a light calcined material calcined at temperatures ranging from approximately 750° C. to approximately 1,200° C.;
• a shrinkage reduction agent, the shrinkage reduction agent including at least one of:
• wherein each R independently includes one of a hydrogen atom and a C1 to C2 alkyl, each R′ independently includes a C1 to C2 alkyl, and n is an integer from 1 to 2;
• and
• HO(AO)xH, wherein A is one of methylene, ethylene, and propylene, and x is an integer from 1 to 10;
• and
• portland cement.

A dry, flowable-powder consisting essentially of:

• magnesium oxide including a light calcined material calcined at temperatures ranging from approximately 750° C. to approximately 1,200° C.;
• a shrinkage reduction agent, the shrinkage reduction agent including at least one of:
• wherein each R independently includes one of a hydrogen atom and a C1 to C2 alkyl, each R′ independently includes a C1 to C2 alkyl, and n is an integer from 1 to 2;
• and
• HO(AO)xH, wherein A is one of methylene, ethylene, and propylene, and
• x is an integer from 1 to 10;
• a super absorbent polymer including a polyacrylic and polyacrylamide copolymer;
• and
• portland cement.