JPH0257658B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, the strength of structural concrete has been estimated using the following method.

(a) Estimated from test values of specimens made from concrete immediately before pouring.

(b) Estimated from test values of core specimens cut from poured concrete.

(c) Estimated from test values of the pull-out strength of bolts etc. driven into concrete.

(d) Based on the results of a nondestructive test using a Schmidt hammer, etc. to measure surface hardness, shock wave propagation speed, etc.

In method (a), there is a large possibility that the relationship between the strength of the specimen and the concrete strength of the structure will be affected by the curing method, construction method, etc., and there is also a possibility that the specimen may be mistaken for another specimen.

Method (b) causes great damage to the structure and is time consuming.

In method (c), the pull-out strength is not a direct measurement of the concrete's compressive strength, so the estimation of the compressive strength from the test results is influenced by many factors and may cause damage to the structure.

In method (d), the relationship between test values and concrete strength is more indirect and is influenced by more factors.

The present application was invented in view of the above-mentioned drawbacks, and is a structure using specimens taken from protrusions provided on the concrete surface, which allows the strength of structural concrete to be accurately and easily tested without damaging the structure. This paper relates to a method for testing the strength of concrete.

In the present invention, a protrusion is provided in the concrete formwork at the time of pouring, and at the same time as concrete is poured into the structure, the protrusion is molded with the concrete filled in the protrusion, and the protrusion is removed when the test material is ready. The purpose is to simply and easily and accurately determine the strength of structural concrete by cutting it out as a specimen and conducting a compression test.

Now, to explain an example, when constructing a concrete form, a convex part is provided in a part of the concrete form, and then concrete is poured into the concrete form, and at the same time, the convex part is also filled with concrete and cured. After that, when the test material is ready, the protrusion formed by the convex part is cut out and a compression test is conducted as a specimen to determine the strength of the structural concrete.

In forming the convex portion A, a molding frame 2 made of metal, synthetic resin, or transparent synthetic resin is fitted from the inside into the window 3 provided in the formwork 1, and then concrete is poured. The protrusion 4 is formed integrally with the mounting structure.

In addition, the appropriate shape of the convex part is a prism of about 10 x 10 x 20 cm, and if the shaft is installed horizontally, both end faces of the 10 x 10 cm will be in contact with the formwork 1, and the surface of the formwork 1 will be If you make it a strong flat surface, both ends will be flat and there is no need for capping.

Further, as shown in the figure, it is also possible to form a cylindrical specimen when a concrete placement guide frame portion 2a is formed at the upper portion and a cylindrical portion 2b is formed at the lower portion.

A good method is to attach the molding frame 2 so that it can remain even when the molding frame 1 is removed, and to leave it as it is even when the molding frame 1 of the structure is removed.

By adjusting the heat insulation properties of the forming frame, the concrete curing temperature of the protruding portion 4 can be brought close to the curing temperature of the structural concrete to some extent.

Furthermore, when the molding frame 2 is made of transparent synthetic resin, it is possible to observe how the convex portions A are filled with concrete.

The protrusion 4 can be easily cut off by applying a line load with a tool B as shown in FIG.

Furthermore, if a △-shaped groove 5 is provided at the cutting position, cutting becomes easier.

As mentioned above, after providing a convex part in a part of the concrete formwork when constructing the concrete formwork, concrete is poured into the concrete formwork, and at the same time, the convex part is also filled with concrete, and after curing,
The strength of the structural concrete can be determined by cutting out the protrusion formed by the convex part and using it as a test specimen to determine the strength of the structural concrete. It is accurate and can be easily tested and determined.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the convex portion, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is a side view of the part where the tool is used.

Claims (1)

[Claims] 1. After forming a convex part on a part of the concrete formwork when constructing the concrete formwork, pour concrete into the concrete formwork and at the same time fill the convex part with concrete.After curing, the convex part is removed when the test material is ready. 1. A method for testing the strength of structural concrete, characterized in that the strength of the structural concrete is determined by cutting out a protrusion formed by the method and performing a compression test as a specimen.