Many traffic areas in the municipal road constructions are classified into load classes Bk1,8 up to Bk100 and, thus, according to the General Circular on Road Construction No. 04/2013 on the alkali reactivity, attributed to moisture class WS. The suitability of aggregates and/or concretes for the class WS can be proven by a WS basic test or an ASR-performance test. As in many regions the respective proofs are missing ready-mix concrete is not deliverable. The classification WS was chosen for highways (high dynamic load and external alkali supply).
In the case of municipal areas the dynamic load, however, is not so high due to the lower velocity. Moreover, often no thawing agents but dulling agents are used. Therefore, the alkali supply and the risk of a damaging ASR should be lower. Possibly the moisture class WA or a comparable classification is sufficient.
This research project in the field of municipal traffic areas was aimed at basic findings for a practice-oriented classification of the moisture class and the respective assessment of concrete by means of a performance-test. For this purpose concrete pavements without showing signs of a damaging ASR after approx. 10 years of use were tested. From this pavements drill cores were taken and assessed with a procedure especially developed for the moisture classes WA. In the case of a positive result a concrete with the same composition could be used under comparable external conditions. As a result an increasing number of regionally available aggregates could be used. The practice-oriented choice of the moisture class and the assessment by a suitable test procedure protect the contractors and the customers from misuses caused by a damaging ASR and, thus, enable the use of regionally available aggregates. As a consequence durability properties and profitability of constructions will be improved.
