| abstract |
A drying shrinkage-reducing agent which comprises a polymer containing as an essential component at least one structural unit (I) represented by the following formula (1): [Chemical 1] wherein R1, R2, and R3 independently stand for a hydrogen atom, a methyl group, or a -(CH2)pCOOX group, wherein X stands for a hydrogen atom, a monovalent metal, a divalent metal, an ammonium group, an organic amine group, or a hydrocarbon group, and p is an integer of 0 - 2; and R4 stands for a hydrocarbon group of 4 - 30 carbon atoms, and exhibiting surface tension in the range of 25 - 50 mN/m in a solution containing 0.2 mass% of the polymer in a cement supernatant is provided. The drying shrinkage-reducing agent manifests no dispersability in an amount capable of attaining necessary drying shrinking-reducing properties and, when used in combination with a dispersing agent, acquires ability to adjust the dispersability and the drying shrinkage-reducing properties fit for the purpose. |