DUE, ANGELICA _D,, Department of Resource Engineering and Agricultural Mechanization, College of Engineering and Computer Studies, Pampanga State Agricultural University, Magalang, Pampanga. August 2022. "Potential of Cassava Stalk Ash as Additive for Paving Blocks". Adviser: Engr. Emilio S. Guzman This paper evaluated the potential of cassava stalk ash (CSA) as an additive for paving blocks. Consisting of different percentages of sand, cement, and cassava stalk ash, the blocks were prepared in terms of weight. The statistical method used is the Analysis of Variance. On the slump test results, all treatments were labeled as "true slump." On the water absorption test, Analysis of Variance showed that all treatments were not significant at the 5% level F-test. Treatments with CSA ash absorbed water as much as the control sample absorbed. In the drop test, one (1) meter above the ground, paving blocks did not crack or break, but they had a small chipped portion. The compressive strength of the three ratios of cassava stalk ash was found to be the strongest at 28 days of curing compared to blocks with 10% CSA and 15% CSA. Based on the compressive strength, the paving block with 5% CSA was the strongest among treatments, as it had a mean compressive strength of 8.75 MPa at seven (7) days of curing and 15.74 MPa at 28 days of curing. The control had the greatest mean compressive strength of 10.44 MPa. CSA paving block is compared to the cost of commercial paving blocks. Paving; blocks with CSA are more economical, with Php14.98 for 5% CSA, Php14.21 for 10% CSA, and Php13.39 for 15% CSA. Regarding commercialization, CSA with 15% is hight recommended since it produces more blocks than CSA with 5% and 10%.