Resurface cracked concrete paths with a strong mortar mix of one part of cement to three parts of sand. First, break up the whole path into small pieces with a heavy hammer. Make sure the pieces are well rammed down and then wedge boards into position with wooden pegs at 1 m 3ft intervals on each side of the path. Extending them above the existing surface by 25 mm. Coat the surface with a PVA bonding agent. Obtainable from builders merchants. This stops the existing concrete absorbing too much moisture from the new mix.
After hosing the path to wet it thoroughly, pour the mortar mix over the path up to the height of the boards. Allow it to harden for at least a week before removing the boards and cover it with damp sacking to slow the drying time.