Depolymerization of poly(ethylene terephthalate), PET, textile waste was performed with a manganese acetate catalyst. Different ratios of diethylene glycol (DG) to propylene glycol (PG) were used for glycolysis. The weight ratio of PET to the glycol mixture was 1:0.65. The glycolyzed products were analyzed for hydroxyl value and the amount of free glycol. These glycolyzed products were reacted with mixtures of sebacic acid (SE) and maleic anhydride (MA) to prepare a series of unsaturated polyesters having different molecular weights. The molecular weights of the unsaturated polyesters produced were determined by the end group analysis. The obtained polyesters were dissolved in styrene (Sty) monomer and their curing behavior was investigated. Polymer concretes (PC) made with these resins were investigated for their compressive strength. The data revealed that the properties of the PC based on recycled PET are comparable to PC made from virgin materials. We concluded that recycling of PET waste may provide a potentially lower cost source of resin, and its recycling in PC will also help reduce an environmental problem.