Improvement of Estimation Accuracy of Early Age Compressive Strength of Tunnel Lining Concrete and Deployment to Demolding Management
By R. Matsumoto, T. Saito, M. Inagaki and H. Endo
Concrete Journal, Vol.62, No.2, Feb. 2024
- Synopsis
- In mountain tunnels, lining concrete is often demolded at an early age of about 12 to 20 hours after placing, and the maturity is sometimes used for judgment of demolding readiness. A strong correlation between maturity and compressive strength has been recognized, but this correlation is based on a relationship over a longer term than the demolding period of lining concrete, and there was concern that the estimation accuracy of early age compres sive strength might be insufficient. Therefore, to improve the correlation between maturity and compressive strength, we conducted compressive strength tests under various temperature conditions targeting early ages and developed a compressive strength estimation formula better suited for early ages. Additionally, we applied a management method based on the developed compressive strength estimation formula to the demolding of lining concrete in actual construction, and confirmed its practical applicability.
- Keywords:
- Mountain tunnel, Lining concrete, Maturity, Early age, Estimation accuracy, Demolding management, Heat curing
