Construction Works of Large Scale Shaft Structures
by Using Low-heat Portland Cement
-The Metropolitan Area Outer Discharge Channel Construction Project-
By M.Mochizuki, M.Takayashiki, S.Terasawa, H.Nakayama and T.Ohtomo
Concrete Journal, Vol.34, No.6, June 1996
- Synopsis
- The Metropolitan area outer discharge channel for flood control on the middle reaches of Nakagawa and Ayasegawa rivers is the first large scale undergroundchannel construction project implemented by the ministry of construction. The project has already reached the stage of construction of large scale shafts. Because the shafts consist of extremely massive members, the care for mass concrete was examined in the planning to ensure the thermal cracks that cause problems in watertightness could be prevented and that the concrete structure satisfies the quality and performance requirements. As a result, application of low-heat portland cement for the thermal cracking control was decided. In this report, the effect of use of low-heat portland cement on the reduction of thermal cracking, and the evaluation method of quantity and width of the induced cracks were clarified.
- Keywords:
- low-heat portland cement, thermal cracking, width of crack, mass concrete, underground discharge channel
