JPH08145861A - Insulating curing container for concrete specimen - Google Patents

Abstract

PURPOSE: To obtain a concrete specimen showing the temperature history of the same degree as a structural body, by forming a container of a synthetic resin by expansion molding to be equal in thickness at a bottom, a side wall and a lid member thereof, setting the volume ratio between the container and concrete specimen to be accommodated in the container in a specific range, and keeping the same environment as inside the structural body. CONSTITUTION: The curing container for forming a concrete specimen to be used to estimate properties of a structural body of a reinforced concrete structure is formed of a synthetic resin by expansion molding (polystyrene foam). Members of a bottom, a side wall and a lid of the container are equal in thickness, and the volume ratio of the container and concrete specimen is set to be 1.6-2.0. The temperature history of the specimen can be made approximately equal to that of the structural body by combining the pressure of members, a count of specimens to be accommodated in the container and the internal cubic volume of the container.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This patent relates to a curing container for preparing concrete specimens used for estimating the physical properties of structures (columns and beams) of a reinforced concrete building.

[0002]

2. Description of the Related Art The physical properties of a structure are estimated from specimens having different curing environments (standard underwater curing, on-site underwater curing, on-site sealing curing).

[0003]

The difference in the curing environment described in the preceding paragraph is that the temperature history of the specimen and the absorption or transpiration of water are different from those of the structure. Regarding the absorption and evaporation of water, a simple impermeable paper frame is used, and the top part is sealed with a vinyl cap to maintain the same environment as inside the structure. Therefore, the remaining issue is the development of a curing container that creates a specimen that exhibits a temperature history similar to that of the structure.

[0004]

The temperature history inside the structure varies depending on the cross-sectional dimensions and the ambient temperature (outside temperature) even if the composition is the same. By using polystyrene foam as the material of the container and combining the thickness of the member with the number of specimens to be stored (minimum 9) and the internal volume of the vessel, it is possible to make the temperature history of the specimen and structure similar. It was confirmed by an experiment. Table-1 shows the standard dimensions of the container according to the number of specimens to be stored. (Refer to Fig. 1 for the code)

[0005]

[Operation] The concrete being poured into the structure is sampled (JI
S A 1115), a test piece is made with a paper simple mold (JIS A 1132). The specimen is stored in a container having a member thickness corresponding to the cross-sectional size of the structure. A thermocouple is installed at the center of the cross section of the specimen and the structure (inside the mold) and the temperature is measured to confirm that the temperature histories of the specimen and the structure are similar.

[0006]

[Example] A column having a cross-sectional dimension of 90 × 90 cm and a column of 60 × 6
A 5 cm beam was cured with a container made of 10 cm and 5 cm heat insulating material (polystyrene foam) respectively (15 columns and 8 beams) and part of the temperature measurement results It shows in Table-2. Estimating from these results, the thickness of the container is set to about 1/10 of the minimum cross-sectional dimension of the structure, and the container is installed at the same environmental conditions as the structure, so that the temperature history of the structure is about the same. It is now possible to create a specimen that shows. What is the average environmental temperature in the table?
It is the average outside air temperature (structure) or the average indoor temperature (specimen) within the time required to reach the maximum temperature after concrete is poured.

[0007]

As described above, the specimen cured in the heat insulating container according to the present invention can be estimated to have the same degree of environment as the strength developing process of the structure in the sealed state and the temperature history. Therefore, it is appropriate to judge the physical properties of the structure from various test values obtained by using this specimen. In particular,
By using the test value of this test specimen to confirm the initial strength when the mold is released from the mold or to judge the strength of the structure (long-term strength), it is possible to manage the structure accurately.

[Brief description of drawings]

FIG. 1 shows a plan view and a side view of a model (7) shown in Table-1.

Claims (1)

[Claims] 1. A container molded from a synthetic resin foam molding (generally referred to as polystyrene foam or styrofoam (JIS A 9511)) having the same bottom, side wall, and lid member thicknesses and an internal volume (capped state). ) To the volume of the concrete specimen to be stored (α) in the range of 1.6 to 2.0.