Amorphous alloys, also known as metallic glasses, are a type of novel amorphous material discovered by chance. This discovery has greatly enriched the field of metal physics, spurred the rapid development of amorphous physics and materials science, and propelled amorphous physics to the forefront of condensed matter physics. As an important and challenging branch of this discipline, amorphous physics now plays a pivotal role in understanding the complexities of non-crystalline materials. Amorphous materials, characterized by their unique properties, are not only widely used in daily life and high-tech fields but also serve as model systems for studying significant scientific issues within materials science and condensed matter physics. This paper provides a comprehensive review of amorphous alloys, discussing major scientific issues and challenges in amorphous science, the formation mechanisms of these materials, their structural characteristics, and their physical and mechanical properties. Additionally, it explores the various applications of amorphous materials and forecasts future research trends, significant issues, development prospects, and directions within this vibrant field.

The application of rubber in geotechnical engineering has gained widespread popularity due to its potential to enhance the engineering properties of foundation fills while reducing environmental pollution. This study focuses on investigating the influence of the rubber fiber content on the performance of calcareous sand by conducting a series of triaxial tests. The effects of the rubber fiber content and axial pressure on the strength, deformation, permeability, and particle breakage of rubber–calcareous sand were systematically studied. The experimental results reveal that increasing the rubber fiber content reduces the strength of rubber–calcareous sand, but it also inhibits the shear dilation and mitigates the occurrence of rupture surfaces: the sample with a rubber content of more than 10% only has shear-contraction. Both the rubber fiber content and axial stress contribute to the increased impermeability of rubber-modified calcareous sand, although they exhibit different characteristics. The relationship between the rubber fiber content and permeability coefficient is linear, while, under increasing axial stress, the permeability coefficient initially decreases rapidly; when the deviatoric stresses exceeds 1000 kPa, the decreasing rate slows down. Furthermore, rubber fiber significantly reduces particle breakage in calcareous sand. The relationship between the input energy applied to rubber-modified calcareous sand and the relative breakage rate of calcareous sand can be well-fitted with a power function. Samples with a higher rubber fiber content exhibit a lower relative breakage rate of calcareous sand under the same absorbed input energy. Through the research results of this paper, the best rubber ratio can be selected as the road filler in engineering practice to ensure both cost-effectiveness and environmental protection.

The low bearing capacity and high crushability of coral sand pose major challenges to island and reef foundation engineering. Herein, a newly developed non-isocyanate polyurethane was used to reinforce coral sand and the unconfined compressive behavior of polyurethane-reinforced coral sand was investigated based on an orthogonal experimental design. The effects of particle gradation, the mass ratio of polyurethane to sand and moisture content on strength, deformation, and energy evolution were analyzed. The results show that the highest uniaxial strength of 5.48 MPa was obtained for naturally graded coral sand with a polyurethane mass ratio of 30% under dry conditions. The moisture content was identified as the dominant factor affecting the strength, and elastic modulus of the reinforced samples. Increasing moisture content significantly reduced the crack initiation stress, dilation strength, peak strength and elastic modulus, while increasing Poisson’s ratio. In contrast, a higher polyurethane mass ratio improved the strength, stiffness and energy dissipation capacity, whereas particle gradation primarily influenced the crack initiation stress level. Under unconfined compression, the reinforced samples mainly exhibited ductile shear failure involving edge breakage, particle sliding, delamination and rupture of the cured polyurethane film. Microscopic observation indicated that the cured polyurethane worked as a surface film, an interparticle bridge and a pore-filling phase within the coral sand matrix. The enhancement in mechanical behavior was mainly associated with polymer bridging, pore filling, local interfacial adhesion and mechanical interlocking.

The weak layer has good attenuation performance when it comes to the explosive stress wave, which can be used in protective structures. In this paper, a cement mortar specimen was designed, cast, and tested. Under inner explosion, due to the expansion of air in the explosive hole, the tensile cracks formed around the explosive hole are mainly in a damage pattern. In ordinary cement mortar, the transmittance is decreasing as the distance increases. At a distance of 8 cm to 14 cm from the explosive center, the average transmittance is 50.16%, 12 cm to 18 cm, while the average transmittance is 62.89%, increasing by 12.73%. Adding one weak layer into the cement mortar, the transmittance of one weak layer is 43.37%. The effect of increasing weak layers in short spacing is not obvious, and the transmittance of the second and third weak layer is about 80%, much less than the first layer. The softer the weak layer and the larger the wave impedance, the smaller the transmission coefficient is. The research proves that the weak layer has excellent attenuation performance when it comes to the explosive stress wave.