<![CDATA[The increasing amount of Unplasticized Polyvinyl Chloride (UPVC) waste generated from the construction sector has become an environmental concern, highlighting the need for its reutilization as a value-added construction material. This study aimed to analyze the effect of UPVC powder waste content on the mechanical properties of paving blocks and to determine the effective dosage that provides optimum performance. The research was conducted experimentally at the Civil Engineering Laboratory of Universitas Muhammadiyah Mataram using UPVC powder waste as a partial replacement for fine aggregate at proportions of 0%, 0.25%, 0.50%, 0.75%, and 1.00%, both without and with the addition of 2% accelerator. The specimens consisted of paving blocks measuring 20 cm × 10 cm × 8 cm and were tested at the age of 14 days to evaluate compressive strength and water absorption. The results indicated that increasing the UPVC content tended to reduce compressive strength and increase water absorption. In mixtures without accelerator, the average compressive strength decreased from 19.58 MPa to 14.85 MPa, while water absorption increased from 3.13% to 3.34%. The addition of 2% accelerator improved the performance of the paving blocks, as indicated by a compressive strength of 24.53 MPa and water absorption of 2.18% at the 0.25% UPVC variation. Based on the evaluation of the requirements specified in SNI 03-0691-1996, the recommended effective content of UPVC powder waste was 0.25% of the fine aggregate weight with the addition of 2% accelerator, as it provided the best balance between waste utilization and the mechanical performance of paving blocks. The findings demonstrate that UPVC waste has the potential to be utilized as an alternative material that supports sustainable construction and the circular economy.]]>
