Effect of rubber granule size range and morphology on the compressive strength of rubber mortar

Rubber mortar is increasingly utilized in transportation, construction, and repair projects, where compressive strength serves as a critical performance indicator. The size range and morphology of rubber granules significantly influence the compressive strength of rubber mortar. This paper employs a close-up photogrammetry technique to capture scanned images of waste rubber granules and to measure their size range and morphological indices. The generation and distribution of waste rubber granules are facilitated by Python programming, while the analysis is conducted through numerical simulation methods. The key findings are as follows: (1) the size range and morphology of rubber granules exert minimal influence on the elastic modulus of rubber mortar during the elastic phase; (2) for rubber granules of the same ellipticity, a shorter minor axis correlates with an increased load stress that rubber mortar can endure at the same strain level, and it supports a quicker attainment of peak stress, after which there is a rapid decline in stress; (3) for a consistent size range of rubber granules, those with smaller ellipticity facilitate greater load-bearing capacity in rubber mortar under identical deformation levels. This results in a higher peak stress during the continuous deformation of the specimen, thereby enhancing its compressive strength. • A rubber granule model database was obtained using close-up photogrammetry. • Rubber granule morphology features were extracted using a MATLAB program. • Finite element simulation of rubberized mortar specimens under varied conditions. • Impact of rubber granule morphology and size range on mortar compressive strength.