Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Performance of HPC of in service structures

The aim of reviewing in-service structures (Tasks 1.2 and 2.1, as reported in Deliverable D2 [2]) was to get information about damage behaviour of real structures as well as compatible and optimal mix design concepts. The investigated structures present a wide range of different exposure types and application forms (e.g. bridges, road pavements, pre-cast elements, harbour decks), age and strength categories.

The influences of environmental aspects on the properties of HPC were grasped with help of extensive analysis of a high number of in-service structures under different climatic conditions and exposure classes. Therefore a description is given of the geographic location of every in-service structure and its exposure class in order to classify the environmental influences on the concrete. The laboratory examinations focused on the coverage of macro- and microstructure conditions of the concrete. The data collection was a basis for understanding the degradation mechanisms and the practical behaviour.

90 in-service structures and test elements were investigated under different environmental conditions. Compact descriptions of all structures and test results are inserted in a public open database in the section �Older structures�. The D2 Report contains the synopsis of the visual conditions as well as the macro- and micro-structural properties of the investigated constructions. 61 of the investigated structures and test elements were reported in D2.

The following structural investigations and parameter studies were done:

Quantitative investigations:
-Compressive strength
-Mercury Intrusion Porosimetry (MIP)
-Air pore content, spacing factor, A300 content
-Carbonation depth
-Chloride profile
-Capillary water uptake
-Frost testing

Qualitative investigations:
-Visual analysis
-Optical analysis by means of thin- sections
-XRD
-SEM and ESEM
-EDX

The volume of the past experiences with HPC differed between the participating countries. The most experiences exist in the Nordic region because of their extensive field test investigations in the past and many practical applications in different kinds of constructions.

The survey of in-service structures covers a wide range of different concrete types and environmental and mechanical burdens, including:
-Climatic zones from Northern to Southern Europe
-12 types of structures
-Ages of constructions between 0 and 30 years
-7 attack classes according EN 206
-Concrete mixtures with equivalent w/b-ratios from 0.16 to 0.54
-Nominal compressive strengths from 30 to 158 Mpa

Informations connexes

Reported by

Bauhaus-Universitaet Weimar
Coudraystr. 11
99421 WEIMAR (THUER)
Germany
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