摘要:The effectiveness of hollow core concrete bricks made of sand and stone ash mixture as alternative substitute materials has been previously studied, considering their weight, load capacity, construction time, and cost. To obtain an optimal notch model as the interlocking device, this further study is conducted. The previous notch model is in the shape of a 2-cm trapezoid and is varied here to consider a 2-cm rectangular notch model and 3- and 3.5-cm trapezoid notch models. The ratio of sand to stone ash in the mixture is 25:75. The wall specimen refers to the previous studies, which investigated specimens with sizes of 90 × 45 cm2under out-of-plane loading and 60 × 60 cm2under in-plane loading. We found that the 2-cm rectangular notch model is optimal as the interlocking device of the wall made of hollow core concrete bricks, with a flexural strength under out-of-plane loading of 212.29 kN/m2and a flexural strength under in-plane loading of 330.92 kN/m2, representing increases of 14.63 and 175.77%, respectively, compared to the values obtained in previous studies. The failure or collapse initially starts from the material parts and then continues to the connection ones.