COMPARISON OF K-350 CONCRETE WITH INTEGRAL WATERPROOFING AND K-500 CONCRETE IN TERMS OF WATER TIGHTNESS

Concrete is the primary material in construction, particularly for underground structural elements that are frequently exposed to groundwater. A common issue in underground construction is leakage caused by insufficient water tightness of concrete. This study aims to compare K-350 concrete with the addition of integral waterproofing admixtures to K-500 concrete without integral waterproofing, focusing on the characteristics of water permeability, absorption, and penetration. The research method involved preparing cylindrical specimens and conducting laboratory tests in accordance with SNI standards. The results indicate that the water absorption of K-500 concrete is lower (1.00–2.25%) compared to K-350 (1.16–2.52%), while water penetration was recorded at 46.04 mm for K-500 and 48.35 mm for K-350. Permeability testing showed that K-350 concrete with waterproofing had a value of 1.37×10⁻⁸ m/s, lower than K-500 concrete with a value of 1.85×10⁻⁸ m/s. Therefore, the addition of integral waterproofing to K-350 concrete results in better permeability performance, although its water absorption and penetration levels are lower than those of K-500 concrete.