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

摘要

PROBLEM TO BE SOLVED: To improve the compacting properties and low shrinkability of a strain hardening type cement based composite material. SOLUTION: The strain hardening type cement based composite material having self-compacting properties and low shrinkability is the crack dispersion type fiber reinforced one exhibiting a tensile strain of≥1% in a tensile test of a hardened body in an age of 28 days, and is obtained by blending a prepared matrix in the following [M1] with PVA (polyvinyl alcohol) short fiber in the following [F1] by an amount of >1 to 3 vol.%: [M1] where, in the use of normal portland cement or low heat portland cement, the weight ratio between water and a binder is≥25%, a unit water content is 250 to 400 kg/m3, the weight ratio between a fine aggregate and the binder (S/C) is≤1.5 (inclusive of zero), the maximum particle diameter of the fine aggregate is≤0.8 mm, the mean particle diameter of the fine aggregate is≤0.4 mm, the content of an expanding admixture is <100 kg/m3, and the content of welan gum is 0.05 to 1.0 kg/m3; and [F1] where the diameter of the fiber is≤50μm, the length of the fiber is 5 to 25 mm, and the tensile strength of the fiber is 1,500 to 2,400 MPa. COPYRIGHT: (C)2003,JPO