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 SiO2 in CSA significantly promotes the secondary hydration of cement, leading to increased formation of calcium silicate hydrate (C-S-H) and thereby enhancing the mechanical strength of CSHC. This research provides a theoretical foundation supporting the engineering application of CSA as a supplementary cementitious material in the production of high-strength biomass ash concrete.
Wang et al. (Wed,) studied this question.