Currently, most of the waste plastics cannot be recycled, causing serious environmental concerns. In this research, we investigated a compaction formation technology to fabricate structural materials with thermoplastic binders. When the compaction pressure was 70~100 MPa, with only ~10 wt% polyethylene binder, the flexural strength was greater than that of typical steel-reinforced concrete, suitable to many construction applications. Because construction materials are tolerant to impurities, our work may provide a promising opportunity to recycle waste plastics and to reduce the portland cement production.