As a high-quality building material exhibiting excellent toughness and durability, ultrahigh-performance concrete (UHPC) is increasingly being used in the construction industry and as building reinforcement. During the reinforcement of existing concrete structures with UHPC, their interface is the weakest part of a structure. Interface bonding ensures the operation of two types of materials together. However, existing studies rarely report the bonding of the UHPC–normal concrete (NC) interface. Herein, the existing test methods and interface bonding mechanisms are summarized. Subsequently, the differences among relevant design codes are investigated by comparing different theoretical formulas. Important influencing factors of the reinforcement method, namely, interface roughness, fiber type and content, interface agent type and content, moisture content, existing concrete strength, cementitious material content, curing conditions, freeze–thaw cycles, and chloride ions, are also considered. Further, the enhancement mechanism of the characteristics of the UHPC–NC interface is clearly described. Finally, the shortcomings and application prospects of the interfacial bonding properties are highlighted.

The climate crisis is one of the most important problems today. In the process of human building, the use of cement, steel, and other industrial materials in the process of building construction and recycling has brought a huge burden to the natural environment. Earth is one of the oldest building materials, its availability and insulation make it an excellent constructive solution in human history. Among several existing earth construction techniques, rammed earth is one of the most relevant. In this paper, a numerical model of the rammed earth folk house in Mianyang was established, and an experimental device was built to verify it. With the typical meteorological year data of Mianyang in northwest Sichuan, the heat and moisture transfer in rammed earth wall, as well as the indoor thermal and moisture environment were numerically simulated. The results show that the rammed earth wall weakens the temperature fluctuation of the inner surface of the wall and makes the peak temperature of the inner surface of the wall lag the outer surface. The relative humidity in the center of the rammed earth wall can be maintained at about 60%, both in winter and summer. The moisture absorption and desorption capacity of rammed earth walls without inner decorative materials is about three times that of gypsum board, and the use of a waterproof coating will render the rammed earth wall almost unable to adjust the indoor relative humidity. Additionally, the use of decorative materials will increase the fluctuation range of indoor relative humidity and the risk of mold breeding.

Prefabricated panel-assembled wall systems, comprising a confining frame and infill lightweight panels of autoclaved aerated concrete (AAC), are widely employed in framed structures. Different from studies on a main frame with infill walls, this study aimed to explore the seismic performance of partition walls, which were fabricated with AAC panel-assembled walls and located outside of the main frames. Two full-scale specimens, one with a door opening and the other without, were constructed and cyclic loading tests were executed to examine the failure modes, hysteresis characteristics, envelope curves, ductility, strength and stiffness degradation, as well as energy dissipation capacity of the AAC panel-assembled walls. Additionally, a restoring-force model for the panel-assembled walls was developed and a method for predicting the lateral load-bearing capacity of the AAC panel-assembled walls was proposed. The findings indicated that the panels enhanced the system’s lateral resistance, energy dissipation capacity, and deformation capability. The door frame increased the initial stiffness, peak lateral load and energy dissipation capacity of the AAC panel-assembled wall compared to the wall without a door frame. Compared to the specimen without a door frame, the peak lateral load of the specimen with a door frame increased by 19.7–30.1%. The deformation capacity of the panel-assembled walls aligned with the requirements for concrete framed structures.

This study addresses the low reactivity and poor toughness of diabase tailings (DT), a high-silica industrial byproduct, which restricts their large-scale application in geopolymer binders. To overcome these limitations, a dual-regulation strategy integrating stepwise low-temperature thermal activation (100, 200, and 300 °C) with standard curing (20 ± 2 °C, 95% RH) was developed. This approach aimed to enhance mineral dissolution kinetics and facilitate the formation of a dense, interconnected gel network. XRD, FTIR, and SEM analyses revealed significant decomposition of amphibole, pyroxene, and olivine, accompanied by increased release of reactive Si and Al species, leading to the formation of a compact N–A–S–H/C–A–S–H gel structure. Under optimized conditions (Si/Al = 2.6; activator modulus = 1.2), the geopolymer achieved a 7-day compressive strength of 42.3 ± 1.8 MPa, a flexural strength of 12.76 ± 1.6 MPa, and a flexural-to-compressive strength ratio of 0.308, demonstrating significant improvements in toughness compared with conventional binders. This green, energy-efficient strategy not only reduces energy consumption and CO₂ emissions but also provides a technically feasible pathway for the high-value reuse of silicate-rich mining wastes, contributing to the development of sustainable construction materials with enhanced mechanical performance.

As one of the most dangerous geological hazards in the world, debris flows can destroy trees and structures, break electrical, water, and gas lines, and disrupt bridges and roadways in a short period of time, threatening life and property. In particular, fast-moving large boulders carried by debris-induced destructive impact loading can strike objects without warning. To resist impact loading caused by rocks in debris, this paper proposed an innovative grid-type debris dam (or Sabo dam) design composed of symmetrical cross-sections of steel tubular flange beams and columns. This paper studied the dynamic performance of the tubular flange columns under impact loading by conducting lab tests and numerical simulations. Moreover, the dynamic response of the grid-type debris dam was simulated under various loading conditions. Comparing three different types of columns with similar configurations under the same loading condition, the tubular flange column proposed in this research exhibits better performance in overall strain, displacement, acceleration, and bending conditions. Furthermore, the results also prove that the proposed structure has excellent interoperability and energy absorption capabilities. When increasing the testing impact load, the failure modes of the dam change from dent at the impact point to local buckling and total failure of the structure, which indicates that the structure has superior performance under impact loading.

This study addresses the unique challenge of the partition walls in subway stations, featuring high height, fire prevention, and located outside the main frames, by introducing a confined autoclaved aerated concrete (AAC) panel wall system. Different from studies on a main frame with infill walls, this study aimed to explore the seismic performance of partition walls, which were fabricated with confined high AAC panel walls and located outside the main frames. A custom-designed partition wall, measuring 6600 mm in height, 3400 mm in width, and 200 mm in thickness, underwent cyclic testing. A detailed analysis of specimen’s failure modes was conducted, focusing on seismic behavior such as hysteresis curves, envelope curves, ductility, stiffness degradation, and energy-dissipation capacity. Additionally, the study delved into shear deformation, relative slippage between AAC panels, and reinforcement strains within the specimen. Finally, the D-value method for calculating the initial stiffness of the confined high AAC panel walls and the weak sub-structural approach for determining the load-bearing capacity of confined high AAC panel walls were proposed and validated. The results indicate that the strength degradation factor of the confined high AAC panel walls ranges from 0.971 to 0.716. The drift of its upper portion accounts for 76.94–83.63% of the total drift, while the energy dissipation factor of its upper portion is 0.8–4.8% higher than that of the entire specimen. The yield and ultimate drift rotations of the entire confined high AAC panel wall and its upper portions satisfy the elastic and elastic-plastic inter-story drift rotation limits specified in the Chinese code. The calculated initial stiffness of the confining frame, obtained using the D-value method, closely aligns with experimental results, with a deviation of only 2.48%. Additionally, the load-bearing capacity calculated using the weak sub-structural approach deviates from the experimental average by just 4.30%.