Not all. But there are late fees, refunds, profits lost because your ship now has to travel a larger route and can therefore take fewer roubdtrips, increasing costs per roundtrip due to the longer route etc.. If we just assume a meager 1% actual loss, the concrete would be worth it in two hours. Even with the remaining expenses due to work, this should pay for itself rather quickly.

Quite a lot of shipped goods have tight delivery schedules requirements.