Innovation in the Production of Tactile Paving (Guiding Block) from A Biochar Mixture as a Direction Indicator for Visually Impaired Individuals

This research examines the innovation of creating tactile paving (guiding block) based on a biochar mixture as a directional aid for visually impaired individuals. Biochar is used as an additive to replace a portion of the sand volume with variations of 0%, 5%, 10%, and 20% relative to the concrete volume. The aim of the research is to evaluate the effect of adding biochar on the physical and mechanical properties of concrete, specifically compressive strength, water absorption, slump, and its suitability for non-structural tactile paving applications. The methods used include testing the characteristics of aggregates and biochar according to SNI, planning a concrete mix with a target strength of 25 MPa using the SNI 7656:2012 method, creating cylindrical test specimens of 15×30 cm, and testing slump, compressive strength at 7, 14, and 28 days, and water absorption at 28 days. The results show that the addition of biochar reduces the average compressive strength compared to normal concrete; at 28 days, the compressive strength of normal concrete is 21.703 MPa, while the variations of 5%, 10%, and 20% are 18.495 MPa, 17.929 MPa, and 13.399 MPa, respectively. Water absorption increased from 1.04% (0%) to 1.79% (20%), while the slump value decreased but remained within the planned range of 75–100 mm. Overall, biochar-based tactile paving with 5–10% variation still meets the compressive strength requirements for non-structural elements, while offering potential weight reduction and the use of environmentally friendly materials for accessible infrastructure for the visually impaired.