I can’t say for sure, but the wall I saw was prestressed concrete but was a series of tongue and groove panels. There are interstate walls built like that but I think the post and panels might use less material and have longer sections.
I did a search and found some interesting information about their wall:
Most of the barrier (over 95% of total length) consists of a “multi-layered fence system” [26] ideally 50 m in width. The IDF’s preferred design has three fences, with pyramid-shaped stacks of barbed wire for the two outer fences and a lighter-weight fence with intrusion detection equipment in the middle. Patrol roads are provided on both sides of the middle fence, an anti-vehicle ditch is located on the West Bank side of the fence, and a smooth dirt strip on the Israeli side for “intrusion tracking”.
Some sections (less than 5% of total length) are constructed as a wall made up of concrete slabs up to 8 m in height and 3 m in width. Occasionally, due to topographic conditions other sections of the barrier will reach up to 100 m in width.[27] Wall construction (5%) is more common in urban settings, such as areas near Qalqilyah and Jerusalem, because it is narrower, requires less land, and provides more protection against snipers. In all cases there are regular observation posts, automated sensing devices and other apparatus. Gates at various points are controlled by Israeli soldiers.