Belgium is still a country where the unions are extremely powerful. Even with only 20% of support they are able to put the national railways to a standstill. The majority of people don't strike, so some trains are reported to run. However, it is advisable to not rely on the railways during a strike.
I will be arriving on Brussels airport on a day of railway strikes (the fifth this month!). I know I can use Taxi's and airport bus services. However, if the majority of trains don't run, the number of people that will rely on these services will be numerous, making them less reliable.
To make alternative options I need to know if it is known what percentage of the trains from Brussels airport do run. I don't mind waiting 2 hours if needed, but can you expect to have a train every 2 hours?