In the construction process of an asphalt concrete impermeable core wall, the interlayer bonding of the core wall is the weak link of the core wall structure and also the focus of construction, so it is important to carry out research on the influence of interlayer bonding temperature on the bending performance of an asphalt concrete core wall. In this paper, we study whether asphalt concrete core walls could be treated with cold-bonding by fabricating small beam bending specimens with different interlayer bond temperatures and conducting bending tests on them at 2 °C. The effect of temperature variation on the bending performance of the bond surface under the asphalt concrete core wall is studied through experimental data analysis. The test results show that the maximum value of porosity of bituminous concrete specimens is 2.10% at lower bond surface temperature of −25 °C, which does not meet the specification requirement of less than 2%. The bending stress, strain, and deflection of bituminous concrete core wall increase with the increase of bond surface temperature, especially when the bond surface temperature is less than −10 °C. If the lower bonding surface temperature is less than 10 °C, the upper layer of asphalt mixture with large grain size aggregate cannot be effectively buried in the low bond surface, resulting in flat fracture and brittle damage to the specimen, which is detrimental to construction quality; therefore, the bonding surface should be heated so that the temperature of the bottom bonding surface is 30 °C. If the lower bonding surface temperature is 10 °C or above, no heating is required.

The angle of repose in soil particles plays a key role in slope stability. There was a need for the investigation on the association between the angle of repose in loess particles and the angle of slopes. The fixed funnel methods with different particle sizes were carried out. The pressure of particle gravity weight was obtained based on the vibration stacking test. Four contact structures in loess particles were put forward including the triangular pyramid contact structure (TS), rectangular pyramid contact structure (RS), pentagonal pyramid contact structure (PS), and hexagon contact structure (HS). The particles transformed successively in four kinds of contact structures. The transformation of entropy value of the particles in different accumulation areas was discussed during the process of accumulation. The relationship between the natural angle of repose and the evolution of the contact structures was established. Combined with the existing experimental conclusion that loess particles transform in four stable states, in turn, the reason that the friction angle of uniform sand particles proposed by Shields in 1936 is 33° was explained. The formation theory of the loess angle of repose was well extended to speculate the formation process of the loess slope system. It is verified that loess slopes were mainly distributed under 30°.