STRAIN HARDENING TYPE CEMENT-BASED COMPOSITE MATERIAL HAVING SELF-COMPACTING PROPERTY AND LOW SHRINKABILITY

摘要

PROBLEM TO BE SOLVED: To improve the compacting property and low shrinkability of a strain hardening type cement-based composite material.;SOLUTION: The strain hardening type cement-based composite material with a low shrinkability is a crack dispersion type fiber reinforced cement-based composite material having a tensile strain of ≥1% in a tensile test of the hardened body in a material age of 28 days and is obtained by blending a prepared matrix of the following [M1] with PVA (polyvinyl alcohol) short fiber of the following [F1] by an amount of 1 to 3 vol.%. It has a self-compacting property. [M1] is prepared by using normal, low heat, or moderate heat portland cement, where the weight ratio of water to a binder is ≥25%, the unit water content is 250-400 kg/m³, the weight ratio of fine aggregate to the binder (S/C) is ≤1.5 (inclusive of zero), the maximum diameter of the fine aggregate is ≤0.8 mm, the average diameter of the fine aggregate is ≤0.4 mm, the content of an expansive admixture is 100 kg/m³, and the content of a bio-saccharide-based thickener is 0.025 to 1.0 kg/m³. [F1] is as follows: the diameter of the fiber is ≤50 μm, the length of the fiber is 5-25 mm, and the tensile strength of the fiber is 1,500-2,400 MPa.;COPYRIGHT: (C)2005,JPO&NCIPI