The addition of waterproofing to concrete aims to reduce porosity and is expected to be more watertight. However, the addition of a waterproof layer to the concrete can reduce its performance of the concrete. Therefore, researchers are trying to innovate an integral mixture of waterproofing concrete with fly ash (FA) as a filler. FA added to the integral waterproofing concrete mix is expected to improve its mechanical properties, including the modulus of elasticity. The Madrid Parabola Formula and Desay & Khrisnan Formula are usually used in calculating the stress-strain distribution of concrete. This case aims to determine the physical and mechanical properties as well as the stress-strain distribution equation by adding FA to integral concrete waterproofing. In this study, the specimens used were cylindrical in shape with a size of 15 cm x 30 cm. The ingredients are PPC cement, sand, gravel, 1.5% integral waterproofing added (Damdex brand), and the addition of FA from cement weight 0% to 15% in 5% increment intervals. Tests for compressive strength, split tensile strength, and modulus of elasticity tests were carried out in reference to ASTM C39/C39M-18, 2018, ASTM C 496/C 496M – 04, 2004, and ASTM C 469 – 02, 2002. The results showed that the more FA was added, the more strength increased. The Desay-Khrisnan stress-strain formula is more suitable for this concrete.
