State laws differ so you will need to research this with your state's Department of Motor Vehicles or Department of Transportation to find out if the reduced speed limits still in affect if the work zone is non-active.
In general we have found that if the reduced speed limit is posted that it is in affect even if the work or construction zone is not active. There are some states or areas that say the reduced speed is only in affect when lights are flashing on the signs though.
In other places we have seen that work zone tickets are only doubled if there are workers present when you are cited for the offense, however the reduced speed limit still applies whether workers are present or not. This is usually due to the fact that work zone or construction areas still make it difficult for traffic to maneuver in and around.
For instance if the work area has construction barrels, orange cones, temporary concrete barriers, etc up at the scene even when workers are not present then in general the work zone reduced speed applies at all times due to extra obstacles these work zone items make for the driver.
As we mentioned earlier check with the DMV to find out if work zone reduced speeds are always in affect or only if workers are present. Then to find out what your penalties will be for the citation you received contact the court listed on the traffic ticket.