Mechanical Properties of Lightweight Cementitious Cellular Composites Incorporating Micro-Encapsulated Phase Change...

Current construction materials face limitations in balancing mechanical strength with thermal insulation properties. Traditional foam concrete provides insulation but often lacks sufficient compressive strength for structural applications. Prior research has shown that cellular structures can reduce material weight while maintaining load-bearing capacity. However, integrating phase change materials into cementitious systems without compromising mechanical performance remains a challenge. No prior work had resolved how to incorporate micro-encapsulated phase change materials into cellular composites without negatively affecting strength. This gap motivated the exploration of digitally architected structures combined with phase change materials. The uncertainty around how structural randomness and material composition influence compressive behavior remained unresolved. The need for lightweight, thermally efficient, and mechanically robust construction materials persists in the industry. This paper's contribution lies in addressing both structural and thermal performance in a single composite system.

The study aimed to evaluate the compressive behavior of lightweight cementitious cellular composites (LCCCs) incorporating micro-encapsulated phase change material (mPCM). The researchers sought to determine whether Voronoi structures with varying randomness could maintain mechanical integrity while enabling thermal insulation. They also wanted to assess the impact of mPCM on compressive properties compared to conventional foam concrete. The motivation stemmed from the need for materials that combine structural and thermal benefits. The team focused on digitally architected structures to control porosity and material distribution. They used 3D printing to fabricate LCCCs with different structural designs. The goal was to identify optimal configurations that balance mechanical performance and thermal properties. The study's scope was limited to 28-day compressive behavior and structural randomness effects.

The researchers designed Voronoi structures with different levels of randomness using digital modeling. They fabricated LCCCs using an indirect 3D printing technique to control porosity and structural layout. Two types of mortars were used: a reference mortar (REF) and one incorporating micro-encapsulated phase change material (mPCM). The compressive behavior of the LCCCs was analyzed experimentally and numerically. They tested samples at 28 days to assess mechanical performance. The study included comparisons between structures with high randomness and conventional foam concrete. Air void defects were monitored to evaluate their impact on compressive strength. The methods combined structural design, material composition, and mechanical testing to assess performance.

The highly randomized Voronoi structures showed minimal negative impact on compressive properties of LCCCs. Mortars with mPCM demonstrated high relative compressive strength compared to conventional foam concrete. The mPCM incorporation did not significantly reduce mechanical performance. Air void defects were identified as a critical factor influencing compressive behavior. LCCCs with high mPCM content maintained structural integrity while offering thermal benefits. The compressive strength remained above 5 MPa in most tested configurations. The study found that structural randomness had a minor effect on strength when combined with mPCM. The results suggest that LCCCs could serve as a novel thermal insulation material with adequate mechanical properties.

The authors propose that LCCCs incorporating mPCM and Voronoi structures can maintain compressive strength while offering thermal insulation benefits. The findings suggest that structural randomness has a minor impact on mechanical performance when mPCM is included. The compressive behavior of LCCCs was found to be comparable to conventional foam concrete. The presence of air void defects was identified as a critical factor affecting compressive strength. The study highlights the potential of LCCCs as a novel construction material. The combination of digital design and material composition was shown to be effective in balancing mechanical and thermal properties. The results support the use of LCCCs in applications requiring both structural and insulation capabilities. The authors emphasize the importance of controlling air voids to optimize compressive performance.