Optimization of mix proportions and hydration study of high-strength concrete incorporating corn stalk ash and silica fume as supplementary cementitious materials.

To mitigate environmental pollution caused by the indiscriminate disposal of corn stalks and cement production, this study utilized corn stalk ash (CSA) and silica fume (SF) as partial replacements for cementitious materials in the formulation of biomass ash high-strength concrete. The investigation focused on the effects of three key variables-CSA content, water-to-binder ratio (W/B), and sand-to-binder ratio (S/B)-on the compressive strength of corn stalk high-strength concrete(CSHC). Using an orthogonal experimental design, the analysis determined that the factors influenced the 28-day compressive strength in the following order: S/B > CSA content > W/B.The highest 28-day compressive strength of CHSC, measured at 109.7 MPa, was achieved under the conditions of 15% CSA content, a W/B ratio of 0.21, and an S/B ratio of 1.2. Characterization of hydration products in the highest-strength samples at 7 and 28 days was performed using X-ray diffraction (XRD) and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS). The results revealed that the abundant reactive SiO