From the accounts i have read, the engineers had quite the hand at building the strongpoints, patrol bases and FOBs in Afghanistan. I wasn't there so i could be wrong.
A good example i can relate to, is the building of the Canadian base in Kosovo in 1999. It was built by combat engineers a construction engineers. Platoon houses were also built by combat engineers. That includes roads and weatherhaven accommodations.
In Croatia, combat engineers built all the accommodations, sewage system, ammunition storage facility, roads and all defensive works for the main base for CANBAT 1.
I'm somewhat familiar with what combat engineers do.