Our concrete driveway is about 10 years old. There's a part in the middle that dips down, and when is rains we get a big puddle there. Is there any way to fix this without breaking the concrete up and repouring it?
Try mixing up an epoxy-based, concrete-repair product that has good adhesion, and using it to fill in the sagging areas of the driveway surface until it's level. Next, apply a layer of Quikrete concrete mix - the kind designed to patch spots like the one you're dealing with. This is a vital step, because if you use regular concrete mix, it won't stick. But if you use this patch mix, it will. Quikrete has good step-by-step videos on their website that show you how to do this.