Cover thickness of rebar [Japanese standard]

This article explains the regulation of rebar cover thickness in the Japanese Building Standards Law.

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Contents of provisions in laws and regulations

The stipulated provisions are Article 79 of the Building Standards Law Enforcement Order. Paragraph 1 describes the contents of the basic restrictions, and Paragraph 2 describes the cases where Paragraph 1 does not apply (provided in the notification of the Minister of Land, Infrastructure, Transport and Tourism).

(Article 79 of the Building Standards Law Enforcement Order)

1)
 The cover thickness of concrete against rebar is 2 ㎝ or more for walls or floors other than load-bearing walls, 3 ㎝ or more for load-bearing walls, columns or beams, and walls, columns, floors or beams that are in direct contact with soil or For the rising part of the cloth foundation, it shall be at least 4 ㎝, and for the foundation (excluding the rising part of the cloth foundation), it shall be at least 6 ㎝ excluding the discarded concrete part.

2)
The provisions of the preceding paragraph shall be equivalent to or better than the cover thickness specified in the preceding paragraph by preventing corrosion of the reinforcing steel by water, air, acid or salt, and by effectively adhering the reinforcing steel and concrete. It does not apply to members using the structural method specified by the Minister of Land, Infrastructure, Transport and Tourism and members certified by the Minister of Land, Infrastructure, Transport and Tourism as having properties and strength.

The following is a summary of Article 79, Paragraph 1 of the Building Standards Law Enforcement Order.

The distance from the end of the reinforcing steel to the outside of the concrete is specified.

Rebar cover thickness

important part of the structure
Over 2㎝ Wall( Other than load bearing wall)、floor
Over 3㎝ load bearing wall、Pillar、Beam
Over 4㎝ The next part in direct contact with the soil
Over 6㎝ Foundations of buildings (excluding rising parts of foundations)