Specification and site control of the permeability of the cover concrete: The Swiss approach

摘要: It is recognized that most damage to reinforced concrete structures caused by insufficient durability rather than low strength. In cases, the quality and thickness of cover (covercrete) determine service life structure. Since covercrete influenced, not only mix composition, but also placing curing conditions, it appropriate measure achieved properties on structure just separately cast specimens. Swiss Standard SIA 262 Concrete Construction recommends checking impermeability site. With aim, a non-destructive method air-permeability site has been standardized (SIA 262/1 Annex E). A team experts was appointed Federal Highway Administration (ASTRA) prepare recommendations for specifying, measuring, assessing conformity kT. This paper describes these covering: (a) specification limiting values kT as function exposure class; (b) sampling measurement points; (c) testing (including suitable temperature moisture conditions); (d) evaluation with specified values; (e) expected impact life.