An improved concrete block formed from expandable polystyrene material for use in building insulated concrete-wall structures wherein cavities are defined to receive concrete, comprising:
- a substantially rectangular, box-like, block form having a pair of oppositely disposed, parallel, side walls and oppositely disposed end walls which define a body cavity;
- interlocking means formed about the peripheral edges of said side walls and said end walls, said interlocking means having an elongated rail member formed longitudinally along the upper edge of each of said side walls and said end walls, said rail member including laterally outward extended side-arm members equally spaced apart from each other along the length thereof;
- an elongated channel member formed longitudinally along the lower edge of each of said side walls and end walls, said channel member including laterally outward extended channel members, and said rail and arm members being positioned to be interlocked within respective channels of the lower edges of said walls when said blocks are stacked in a vertical position to form a building structure;
- said rail and said lateral arm members defining a multiplicity of contiguous sockets adjacent the outer edges of said wall members, and said lateral channel members defining a multiplicity of contiguous post members that are arranged to be lockingly engaged in corresponding sockets when said block forms are stacked one above the other;
- wherein said matching sockets and post located along the longitudinal edges of said side walls are formed with corresponding, tapered, wall surfaces for firm interlocking action between stacked block forms;
- a plurality of intermediate, transverse, strut members formed with a pair of tongue members vertically located adjacent the inner surfaces of said side walls, which are integrally formed together with said oppositely disposed side walls, said transverse members including means to be selectively formed as end walls when the length of said block form is cut to a reduced length as needed;
- wherein a multiplicity of cells are defined by said transverse strut member;
- said end walls being defined by a centrally positioned strut member integrally formed between and adjacent the ends of said side walls, and including removable upper and lower insert members, and said insert members being further formed to be mounted to any one of a selected intermediate strut member so as to define an end wall when said block form is reduced in length;
- said upper and lower insert members being formed with vertical side grooves arranged for engagment with matching tongue members formed as part of each strut member, a flanged transverse edge and a shoulder member being further included for mounting engagement with said strut member, so that when said inserts are selectively mounted to any one of said strut means an end wall structure of said block form is established;
- and
- means for cutting said block form transversely to a selective length, comprising:
- a plurality of vertical grooves equally spaced along the outer surfaces of said side walls and recessed therein;
- a plurality of vertical grooves formed on the inner surfaces of said side walls, said inner-surface grooves being defined by a pair of parallel rib members, whereby said inner and outer cutting grooves are aligned with each other, and wherein additional cutting grooves are formed in the upper and lower surfaces of said transverse strut member, whereby said strut member may be divided to receive said upper and lower inserts to define an end wall.