I had an older driveway poured on compacted gravel. Below that is riversand (we live in a riverdelta). Over the years the concrete driveway developed cracks but no significant breakups. The thickness is 4″.
Rather than taking the driveway out (disposal fees are horrendous) I poured another 4″ on top of the old driveway with the usual control joints.
Now I discover that where the cartires sit in their usual location the concrete developed sags and when it rains there are now puddles on the once level driveway.
Can concrete bend like that?