Chenxi Wang

Current asphalt pavement structural design methods often lack a strong quantitative link to materials’ mixtures and mechanical properties and typically ignore the significant tensile–compressive disparities of materials, resulting in notable analysis errors. This study employed the dual-modulus theory to numerically analyze flexible base asphalt pavements under varied configurations, revealing how critical structural responses and fatigue life evolve. This examination also determined optimal layer mixes through mechanical parameter modeling for integrated material–structure design. The results showed that fundamental responses and fatigue life vary nonlinearly with thickness and modulus. The effect of modulus outweighed that of thickness, with the effects of the tensile modulus being more pronounced than compressive ones, and surface transverse strain being most sensitive to both. The recommended compressive–tensile modulus ratios were about 1.5, 2.0, and 1.2 for upper, lower, and base layers, respectively. By using this integrated design method, the optimized pavement structures achieved superior stress distribution, significantly extending the base service life. As a result, more realistic design lifetimes were obtained.

The use of thermal insulated decorative panel materials with low thermal conductivity and high flame retardance is a key step toward energy-saving buildings. However, traditional thermal insulation materials are always highly conductive and inflammable, which restricts their application for new buildings. This study aims to prepare the non-combustible, cement-based EPS mixtures with thermal conductivity lower than 0.045 and density less than 140 kg/m³ and characterize it with mechanical, thermal, and flame retardant properties. The effect of particle size, Silica coated and content of EPS on the physical, mechanical, thermal, and combustion performance are conducted in this paper. The comprehensive indoor tests including density, water absorbing, softening coefficient, compressive strength, tensile strength, moisture susceptibility, thermal conductivity, and scanning electron microscopy (SEM) along with combustion performance are reported to evaluate the effects of several variables on the investigated cement-based nonflammable EPS (CEPS)mixtures. The results show that small and gradation EPS particles significantly improve the comprehensive performance of mixtures. In addition, Silica coated ESP significantly improve the flame retardance of mixtures while reduce the mechanical characteristics slightly. These results contribute to the selection of appropriate materials to enhance the thermal insulation, flame retardance and mechanical properties of CEPS.