How to measure the cracking strength of ultra-high strength fiber reinforced concrete

摘要

To provide a method or the like for accurately and efficiently measuring the crack generation intensity of ultra-high strength fiber-reinforced concrete.SOLUTION: A measurement method of the crack generation intensity of ultra-high strength fiber-reinforced concrete acquires a relationship of a load and strain by placing the load on a columnar specimen which has passed (A) a polishing process of the columnar specimen, (B) a selection process of a measurement object, (C) a pasting process of a strain gauge, and (D) a placing process of the columnar specimen, and measures tensile stress corresponding to a load at a point in which linear elasticity is not established in the relationship of the load and the strain as the crack generation intensity. Here, when one of the following cases occurs within a load range up to 50 kN, that is, (i) when strains of two end faces are inverted (asymmetric) with respect to each other in a positive strain and a negative strain, (ii) when the strain is not generated at one end face, and (iii) when the strain of one end face reaches 1.5 times or higher of the strain of the other end face, the measurement method performs the processes (B) to (D) once again after interrupting the placement and removing the load, and places the load once again.SELECTED DRAWING: Figure 1