The use of Lightweight Cellular Concrete (LCC) as a subbase alternative to typical flexible pavement subbase material in cold regions is gaining attention. Since a setback of using LCC is its high cement content, which is a significant source of carbon dioxide (CO₂) emissions, it becomes imperative to consider this aspect when proposing LCC for pavement applications. This study evaluated the environmental impact of three densities (400, 475, and 600 kg/m³) of LCC produced with two methods (wet and dry mix) and compared to two types of unbound granular material (granular A and B) as flexible pavement subbase. The pavement performance was predicted using MEPDG and WESLEA software and compared with measured field responses as a basis for maintenance strategy. The Life Cycle Assessment (LCA) results showed that lower-density LCC pavements decreased environmental costs by reducing total life CO₂ emissions by up to 16% and reducing environmental impact for Carbon monoxide, Sulphur dioxide, Nitrogen oxide, Particulate Matter (PM)_2.5, PM₁₀ and total PM compared to granular A and B pavements. As LCC density increased, more emissions occurred, showing the importance of density to emissions output. This research demonstrates the potential benefits of using LCC as an alternative subbase pavement material.

The structural capacity of using lightweight cellular concrete (LCC) as subbase layer in the flexible pavement structure was investigated. Three different densities of LCC’s mechanical properties were examined. It was determined that LCC has adequate compressive strength for pavement application for all considered densities. It was also found that it exhibited higher stiffness than granular material. Failure criteria analysis found that the LCC sections could allow twice the traffic loadings than the granular material in terms of fatigue cracking at the surface layer for similar thickness. For rutting, it could allow between seven to twenty-four times more traffic. The LCC could reduce subbase thickness by up to 60% to bear the similar traffic loads as the granular material. Although the analysis indicates LCC's benefits as a potential pavement material, it is recommended that further assessment of life cycle costing and environmental impact be performed to further explore its benefits.

This study in Canada aimed to improve the performance of flexible pavements by comparing the in-place behavior of Lightweight Cellular Concrete (LCC) at three densities with traditional unbound granular material. The research investigated the effect of traffic load and testing temperature on pavement response and determined the structural layer coefficient for the 475 kg/m³ density. The structural layer coefficient for the LCC subbase at this density was 0.22. Results showed that pavements with LCC had over three times less stress at the top of the subgrade compared to the conventional granular material. The Weslea software, which uses a multi-layer elastic theory, appeared to overestimate stress responses for LCC pavements, and the research suggested a prediction modification for more accurate results. Overall, the study demonstrated that lightweight cellular concrete with different densities could improve pavement performance.

The objective of engineers to improve the long-term performance of road infrastructure in changing global climate has led to the development of alternate materials for pavement construction. Lightweight cellular concrete (LCC) is a viable option for colder climates where pavements undergo several freeze-thaw cycles each year, resulting in faster deterioration of pavements. This is due to LCCs’ excellent freeze-thaw resistance, ease of placement, and potential sustainability benefits such as reduced use of virgin material and industrial by-products. However, there is a need to quantify these benefits and develop unified specifications for using LCC in the pavement structure. Therefore, this study examined the performance of flexible pavement sections that included a subbase layer, unbound granular materials for the control section, and three LCC densities (400, 475, and 600 kg/m³) for the LCC sections. Post-construction evaluation of pavement stiffness and roughness were evaluated using a Lightweight deflectometer and SurPro equipment. The results showed that LCC subbase thickness ≥ 250 mm produced over 22% smoother riding surfaces than unbound granular pavements while increasing pavement stiffness by up to 21%. Finally, this study recommends that LCC subbase thickness should not be thinner than 250 mm when using densities below 475 kg/m³ over weak subgrades.

Previous analytical studies have demonstrated that low-density lightweight cellular concrete (LCC) subbase pavements can support up to 20 times more traffic loads than unbound granular subbase pavements while protecting the pavement subgrade from adverse freeze–thaw effects in cold regions. This study examines the possibility of providing better-performing pavements on the field through the construction, instrumentation, and monitoring of flexible pavement sections incorporating three LCC densities (400, 475, and 600 kg/m³) as subbase material compared with unbound granular material in Canada. The effects of daily and seasonal temperatures on pavement critical responses to stress and strains were evaluated. The findings showed that these LCC pavements reduced asphalt concrete tensile strain by over two times compared with unbound granular pavements, and that strain increased with a daily temperature increase. Daily subgrade pressure (stress) change was reduced by up to 68%. The study concluded that longer life pavements could be achieved with LCC subbase thicknesses ≥250 mm.

Concrete is one of the most popular construction materials, but it is still not considered sustainable. The introduction of recycled concrete aggregate (RCA) as a substitute for natural aggregate (NA) might make concrete align with the principles of circular economy. Unlike NA, RCA is not a homogeneous material as it is composed of old aggregates and adherent mortar. It is more porous than NA, so it results in lower strength and higher absorption. Several attempts have been made to improve the performance of RCA; however, not all studies prioritize an approach that can be feasible on a large scale. In addition, factors that enhance or decrease the performance of cast concrete mixes include the aggregate gradation, shape, and quantity of fines. The objective of this paper is to assess how the circularity, quantity of fines, roundness, and surface characterization of aggregates changes over time with respect to treatments such as mechanical and chemical treatments that can be extended on a large scale without a strong environmental impact. It was noted that acetic acid results in a superfluous additional element that does not greatly affect the results, since a considerable difference in the circularity, porosity, and fine number of aggregates can be produced by changing the timing and the size of the steel nuts used in the mechanical treatment.