What truck is needed to carry 7500 kilogram?

That's approximately 16,500 lbs., or 8-1/4 tons. In the US, a single axle Class 7 truck could haul it legally, provided they had a sufficient wheelbase to remain within bridge law and a light enough tare weight to not go over the legal GVWR. To stay on the safe side, a tandem axle straight truck or a single axle with an additional pusher or tag axle would probably be used.