Outline of Revision of JIS A 5308 (Ready-mixed Concrete)
By Y. Tsuji, Y. Masuda, K. Yoshimori and K. Tsujimoto
Concrete Journal, Vol.57, No.8, Aug. 2019
- Synopsis
- A revision of JIS A 5308 was officially announced in March 2019. This article explains the revision history and background of this standard, and the main revised content. In this revision, terms and definitions were newly defined and the item numbers were reviewed and the clause numbers were reordered. In addition, the use of sludge water using "stabilizer" for the purpose of environmental load reduction was newly defined. For high-strength concrete, the standard stipulates that the buyer can specify nominal strength in steps of 1 (N/mm2), and it adds 45 cm and 55 cm as new slump flow categories. Moreover, from the viewpoint of productivity improvement, concrete managed by slump flow was added to ordinary concrete, the slump categories were revised, the mixture plan format was changed, and the water-binder ratio description method was clarified.
- Keywords:
- Ready mixed concrete, JIS A 5308, high-strength concrete, slump flow, stabilized sludge water, mixture plan
