This study presents an experimental investigation on the recycling of waste incineration bottom ash (IBA) as a fine aggregate in the production of interlocking concrete bricks (ICB). Before being used, the concentration of heavy metal in IBA was determined to confirm it is a non-toxic material. In this study, the IBA was used to replace crushed sand (CSA) in the brick mixtures at different replacement levels of 0%, 25%, 50%, 75%, and 100% (by volume). The ICB samples were checked for dimensions, visible defects, compressive strength, bending strength, water absorption, and surface abrasion in accordance with the related Vietnamese standards. The test results demonstrated that the IBA used in this study was a non-toxic material, which can be widely used for construction activities. All of the ICB samples prepared for this study exhibited a nice shape with consistent dimensions and without any visible defects. The incorporation of IBA in the brick mixtures affected engineering properties of the ICB samples such as a reduction in the compressive strength and bending strength and an increment in water absorption and surface abrasion of the brick samples. As a result, the compressive strength, bending strength, water absorption, and surface abrasion values of ICB samples at 28 days were in the ranges of 20.6 – 34.9 MPa, 3.95 – 6.62 MPa, 3.8 – 7.2%, and 0.132 – 0.187 g/cm2, respectively. Therefore, either partial or full replacement of CSA by IBA, the ICB with grades of M200 – M300 could be produced with satisfying the TCVN 6476:1999 standard in terms of dimensions, visible defects, compressive strength, water absorption, and surface abrasion. These results demonstrated the high applicability of the local IBA in the production of the ICB for various construction application purposes.
Keywords:
interlocking concrete brick; waste incineration bottom ash; visible defect; compressive strength; bending strength; water absorption; surface abrasion.