Yazarlar: Serap Erdoğdu, Steen Lykke
Yayın Yeri : 11DBMC International Conference on Durability of Building Materials and Components ISTANBUL, Turkey 11-14 May
Yayın Yılı : 2008
Açıklama : The aim of this paper is to present information about the study performed during the construction work of Marmaray Project to obtain the target of 100 years service life of RC concrete structures. The Marmaray Project in İstanbul includes part of the upgrading of the 76 km commuter rail from Halkalı, in the European end, to Gebze, in the Asian end. This line includes 1.4 km of immersed tunnel, 10.1 km of bored tunnels, 1.3 km of cut and cover tunnel and four underground stations. Serviceability is influenced from various effects such as cracking, deformation, vibration, durability, water tightness and fatigue. Durability is one of the parameters of serviceability of the structure and therefore during the design stage all parameters were evaluated together in order to check compliance with the service life time requirement which was targeted for the overall project. In the Project, concrete classes were determined according to the design requirements of typical structures. The composition of the mixture was optimized by pre-testings and trials to resist the relevant exposure conditions that impact concrete’s durability. This means appropriate cementitious materials for sulfate ressistance, air void system for freezing and thawing and scaling resistance, adequate protection to prevent corrosion either from carbonation, chloride ingress or depth of cover a low paste content to minimize the drying shrinkage and thermal cracking, and the appropriate combination of aggregates and cementitious materials to minimize the potential for expansive cracking related to alkali silica reactivity. Methods to be applied during construction for ensuring durability requirements is another step of the studies which are; proper quality control system for constituent materials, hardening and hardened concrete besides curing of concrete and finally adequate repair method