Sustainable replacement materials for concrete production from renewable resources and waste on interfacial bond properties

Ecological resources are constantly consumed to produce concrete, resulting in environmental damage. This is also one of the issues for environmental sustainability. This study discovers a replacement material of river sand and stone aggregates produced from sustainable utilization of renewables to save the environment. Manufactured sand (M-sand) from industrial by-products and coconut shell (CS), one of the agricultural wastes, are the resources from which material will be used as a replacement for long-term sustainability. This study uses M-sand as fine aggregate and CS coarse aggregate in its places of river sand (R-sand) and crushed stone aggregate for concrete production, respectively. Manufactured sand (M-sand) has a rough surface texture and angular shape, zero silt, is not oversized, and has less adulteration probability than river sand (R-sand). This study investigated the mechanical and Bond properties of coconut shell concrete (CSC) using M-sand and in its place of R-sand. The workability of concrete produced with M-sand was less because of its rough texture and angular shape and required more water. Mechanical properties such as compressive, flexural, and Bond properties of CSC produced with M-sand were intensified compared to R-sand produced. Since coconut shell (CS) was used as coarse aggregate in CSC, bond stress was tested using two different grades of steel with different diameters of bars. Bond stress was assessed experimentally and compared with the hypothetical values recommended by the standards IS 456 and BS 8110. Compared all the test results of CSC with the conventional concrete (CC) mixes produced using both R-sand and M-sand and tested. M-sand produces better higher strength compared to R-sand used in concrete. Hence, it is recommended that the M-sand is used in the place of R-sand to produce concrete without any hesitation.