To investigate the flexural performance of high-titanium heavy-slag concrete composite beams under loading, this study examined the impact of various factors on deflection development and crack propagation as well as the applicability of empirical formulas for monolithic concrete beams. Seven concrete beams were fabricated with variables such as the reinforcement ratio, prefabrication height, and material composition, and were subjected to two-point concentrated loading. By comparing deflection values and crack widths during loading and analyzing the correlations with empirical formulas from standards, theoretical formulas with significant deviations were modified and compared. The study indicated that the cracking moment and deflection correlated with the reinforcement ratio, material structure combination, and composite height. The empirical formulas for the maximum crack width and deflection of flexural members were applicable to high-titanium heavy-slag concrete composite beams, although some discrepancies existed compared with the experimental values. After modifications, these discrepancies were reduced. This research provides a comprehensive analysis of the deformation characteristics and fracture behavior of high-titanium heavy-slag concrete composite beams.

To improve the corrosion resistance of steel fibers under chloride ion attack in coastal environments and enhance the interfacial bonding between steel fibers and concrete, this study utilized an optimized concentration of γ-aminopropyltriethoxysilane (KH550) solution. Through a hydrolysis–condensation reaction, a silane modification protective film was formed on the surface of the steel fibers, leading to the development of a novel anti-corrosive steel fiber reinforced concrete. Semi-cylindrical specimens of both silane-modified and ordinary steel fiber reinforced concrete were prepared. After subjecting these specimens to dry–wet cycles in a chloride salt environment, they were mechanically loaded using a UTM testing machine, and the loading process was monitored using the XTDIC digital speckle technique. Microstructural characterization confirmed that KH550, via hydrolysis–condensation reactions, effectively generated a modification film on the surface of the steel fibers that prevented chloride ions from penetrating and reduced chloride-induced corrosion. Mechanical tests show that the peak load of the modified specimens increased by 4.24%, and the time required for destruction in the stress concentration stage, crack initiation stage, and macro-crack development stage was prolonged and the strain rate was reduced, proving that the interface bonding ability was enhanced. Overall, this technology achieves a synergistic optimization of durability and mechanical performance through an interfacial reinforcement strategy, providing a new approach for protecting coastal engineering structures against chloride-induced corrosion.

To promote the resource utilization of high-titanium blast furnace slag (HTBFS) and advance the development of lightweight prefabricated structures, this study developed a lightweight HTBFS concrete composite beam (HTC composite beam) by replacing natural gravel and sand in concrete with HTBFS coarse and fine aggregates, and incorporating fly ash ceramsite to reduce self-weight. Symmetrically two-point bending tests were conducted on five HTC composite beams with different reinforcement ratios and precast heights, one Integrally cast HTC beam, and one ordinary concrete composite beam. The failure modes, load-carrying capacities, and deformation characteristics were evaluated. The loading process was also simulated using Abaqus, and the numerical results were compared with experimental data for validation. The results indicate that HTC composite beams satisfy the plane-section assumption; increasing the reinforcement ratio improves the load-carrying capacity, and the precast height has positive effect of HTC composite beams’ load-carrying. Compared with the ordinary concrete composite beam, the HTC composite beam exhibited a 12.30% higher load-carrying capacity, smaller deflection, and better deformation capacity. Multiple energy-based indices demonstrated that HTC composite beams possess favorable post-cracking plastic deformation capacity and stiffness retention. The difference between the finite element simulations and experimental results was less than 5%, confirming both the reliability of the numerical model and the accuracy of the experimental data. An economic analysis revealed that this structural system has significant potential for carbon reduction and cost savings, with an overall saving of approximately 141,000–500,000 CNY. These findings provide theoretical and engineering support for the application of HTC composite beams in prefabricated construction and have positive implications for reducing project costs and promoting the industrialization and low-carbon development of prefabricated buildings.