This study investigates the potential of graphene-based additives to improve the mechanical properties of compacted soil mixtures in rammed-earth construction, contributing to the development of environmentally friendly building materials. Two distinct soils were selected, combined with sand at optimized ratios, and treated with varying concentrations of a graphene liquid solution and a graphene-based paste (0.001, 0.005, 0.01, 0.05, and 0.1 wt.% relative to the soil-sand proportion). The effects of these additives were analyzed using the modified Proctor compaction and unconfined compressive strength (UCS) tests, focusing on parameters such as optimum water content (OWC), maximum dry density (MDD), maximum strength (qu), and stiffness modulus (E). The results demonstrated that graphene's influence on compaction behavior and mechanical performance depends strongly on the soil composition, with minimal variation between additive types. In finer soil mixtures, graphene disrupted particle packing, increased water demand, and reduced strength. In silt-sandy mixtures, graphene's hydrophobicity and limited interaction with fines decreased water absorption and preserved density but likewise led to diminished strength. Conclusions from the experiments suggest a possible interaction between graphene, soil's finer fraction, and potentially the swelling and non-swelling clay minerals, providing insights into the complex interplay between soil properties.

As a significant symbol of human civilization advancement, earth construction not only inherits traditional architectural culture but also enjoys worldwide popularity and widespread usage throughout China due to its economic and environmentally friendly nature, as well as its moisture absorption and heat storage advantages. Consequently, earth construction has garnered considerable attention from international scholars. This paper compiles relevant data to review the developmental trajectory of earth construction, while conducting an in-depth analysis of the performance characteristics of earthen materials. Furthermore, it provides a comprehensive overview of the impact of three modification methods on the mechanical and durability properties of earthen materials, along with a discussion on the research concerning the thermal and moisture performance of these materials. Simultaneously, discussions were held on the relevant research findings and potential directions for the development of earthen materials. Finally, conclusions were drawn, suggesting a comprehensive utilization of their thermal and moisture performance, emphasizing the enhancement of their mechanical and durability performance. Additionally, attention was urged towards the economic and ecological aspects during the construction and maintenance phases of earth construction. These recommendations aim to facilitate the sustainable development and widespread application of earthen materials in the future.