Properties of Innovative and Eco-friendly Pavement and Structural Materials Using Waste Marble Sludge Dust, Rice Husk Ash, Coir Fiber, Starch-Based Binder, and Carbon Quantum Dots

This chapter aims to evaluate the properties of innovative and eco-friendly pavement and structure materials using waste marble sludge dust (WMSD), rice husk ash (RHA), coir fibers (CF), starch-based biodegradable binders (S-BDBs), and carbon quantum dots (CQDs). To this end, many innovative composite groups and control composites were prepared. Of them, the first group was the control composites made of S-BDBs. The second group included S-BDBs, WMSD, and CQDs. The third group was prepared with S-BDBs, RHA, and CQDs. The last group consisted of S-BDBs, WMSD, RHA, CF, and CQDs. For making those innovative composites, the S-BDB was heated with water at 198°C for 30 min. The fresh and hardened properties determined on the innovative and control groups of composites were setting time, rheology with slump, density, compressive strength, and tensile splitting strength as required by current international standards for cement-based binders. The results showed that the insertion of CQDs (2.5%) accelerates the setting time of the innovative composites, reduces the density and slump, as well as provides a slight increase in the compressive strength and splitting tensile strength after 28 days. According to the results for strength, the innovative composite containing 70% S-BDB, 30% WMSD, and 2.5% CQDs (S-BDB70%WMSD30%CQD2.5%) and the innovative composite made of 70% S-BDB, 15% WMSD, 15% RHA, 1% CF, and 2.5% CQDs (S-BDB70%WMSD15%RHA15%CF1%CQD2.5%) showed the greatest compressive strength and splitting tensile strength, respectively. It was concluded that CQDs and CF are the most beneficial admixture for the innovative composite bonded by the S-BDBs.