CEMENT BASED HARDENED BODY AND CURING METHOD OF CEMENT MORTAR OR CONCRETE

PROBLEM TO BE SOLVED: To provide a cement based hardened body sufficiently developing concrete strength by curing effect and improving water absorption preventing properties and shrinkage reducing properties to have resistance against surface cracks; and a curing method of cement mortar or concrete.SOLUTION: In a cement based hardened body, its outer layer is impregnated with a concrete curing agent applied from the surface. The concrete curing agent includes: a mixture of fatty acid esters (A) represented by general formula (1); and an alkoxysilane derivative (B) obtained by reacting alkoxysilane, a hydrolyzate thereof, or a polycondensate thereof with a polyoxyalkylene compound represented by general formula (2). A curing method of cement mortar or concrete using the curing agent is also provided. In the formula RCO-O-R(1): RCO is a 12-24C fatty acid residue, where, in the whole fatty acid residues, a ratio of 16-24C long chain saturated fatty acid residues is 3-40 mass%, a ratio of 16-24C long chain unsaturated mono-fatty acid residues is 30-50 mass%, a ratio of 16-24C long chain unsaturated di-fatty acid residues is 20-40 mass%, and a ratio of 16-24C long chain unsaturated tri-fatty acid residues is 0-10 mass%; and Ris a 1-8C alkyl group. In the formula RO-(AO)-H (2): Ris a 1-18C hydrocarbon group; AO is a 2-4C oxyalkylene group; and n is an integer of 1-20.