The aim of this contribution is to improve the physical characteristics of waste ceramic fine aggregates (WCFA) which have a particle size of 0 to 5 mm through surface chemical treatment, while diagnosing: bulk density, water absorption, and apparent porosity. The impregnation protocol involves applying a solution of cement (C) and sodium bicarbonate (SB) to the aggregate surface at the following concentrations (C: 2% and 4%; SB: 2%, 4%, 6% and 8%) and immersion durations of 12, 24, 48, and 72 hours. The microstructural examination consisting of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) with Energy Dispersive Spectroscopy (EDS) was used to determine the physical effectiveness of this treatment to the WCFA accurately. A design of experiments dependent on response surface methodology was created to find the best treatment conditions. Results showed that the sample (4C4SB24H) increased its bulk density by about 11.5% and reduced water absorption by immersion and apparent porosity by 41.3% and 47.9% respectively as compared with the untreated control sample. A normal new calcite distribution was observed, which very well demonstrated the maximum reduction of surface pore spaces, thus confirming the quality of the chosen sample one more time. The statistical interpretation via Box-Behnken (BBD) suggested that the proposed model was very effective since the maximum error was only 7%.
