Effect of hybrid basalt and sisal fibers on durability and mechanical properties of lightweight roadbed foam concrete

To enhance the adaptability of foam concrete in roadbed engineering, there is also a consideration to satisfy the increasing demand for sustainable and green building materials. This research examines the augmenting of the durability and mechanical properties of lightweight roadbed foam concrete (Basalt and Sisal fiber Lightweight Roadbed Foam Concrete - BSLRFC), through the incorporation of basalt and sisal fibers. A meticulous experimental investigation was executed on BSLRFC specimens, which comprised varying volume fractions (0.15%, 0.30%, and 0.45%) and disparate mixing ratios (2:1, 1:1, 1:2), to evaluate their mechanical, durability, and microscopic characteristics. The consequential observations indicate that the performance of the specimens manifests a pattern of initial improvement followed by a subsequent decline with the increasing volume fraction of the mixed fibers. Optimal mechanical attributes and durability performance were realized when the hybrid fibers volume fraction was calibrated at 0.3%, and an appropriate mixing ratio design was incorporated (with a basalt fiber to sisal fiber ratio of 1:2). The comprehensive microstructural analysis revealed the reinforced mechanism for the mechanical characteristics and longevity of the BSLRFC specimens. This provides strong data support for the wider application of BSLRFC in roadbed engineering.