Can vacuum cleaning recover the infiltration capacity of a clogged porous asphalt

The main threat to the performance of porous asphalts is clogging. This study investigated the effect of vacuum cleaning to recover the infiltration capacity of clogged porous asphalts, using two residential roads in Lulea and Haparanda, northern Sweden, which had been in use for 17 and 24 years, respectively. The infiltration capacity of the two pavements was measured using replicate double ring infiltrometer tests before and after cleaning of the clogged asphalt with an industrial vacuum cleaner/sweeping truck. The results of the tests in Lulea showed that vacuum cleaning had the ability to recover the infiltration capacity of porous asphalt; the recovery was greater where clogging was lower. In Haparanda, however, no effect was shown. This was due to a range of factors: age of the road, de-icing material and application rate and lack of maintenance. The study showed that the long term behaviour of the infiltration capacity depends largely on street maintenance, thus regular maintenance is crucial to counteract clogging.