Abstract: An improved insulating block form for use in the construction of concrete wall structures wherein the block form is formed from expandable polystyrene material to provide a lightweight, rigid, box-like structure having a pair of oppositely disposed side walls and end walls which together define a body cavity to receive concrete therein. A plurality of transverse strut members integrally support the side walls and further define a plurality of cells. Each end wall includes a pair of inserts which are adapted to be mounted to the transverse strut member when the elongated block form is required to be cut for a particular installation. The side and end walls are further provided with interlocking members whereby they are readily stacked one above the other and side-to-side in a secure interlocked arrangement.

Abstract: A modular concrete-block form which is shaped in a rectangular configuraiton and has a pair of oppositely disposed side panel members and end enclosure panels to define a body cavity to receive poured concrete therein. The side panels are held in a fixed parallel relation to each other and are further prevented from side-to-side movement relative to each other by a plurality of strut members which are fixedly mounted transversley from one side panel to the other. The unique arrangement of the strut members contributes to a very stable block framework. Each strut member is formed with substantially "H"-shaped tenon members that are slidably engaged with spaced-apart, "T"-shaped slots formed in the inner surfaces of said side panels. The panel structure is firmly grasped within the pair of opposed stud members that define the tenons. The tenons are integrally connected together by means of truss members that further define passages therethrough for flow of wet concrete therebetween.