Sustainable and cost-effective ultra-lightweight engineered cementitious composite: Design and material characterization

Lightweight ECC (LWECC) has been extensively concerned due to its superior tensile performance, durability and low self-weight. However, the high environmental impact and material cost of ECC impede its broader engi-neering applications. The objective of this research is to develop a novel sustainable and cost-effective ultra-lightweight engineered cementitious composite (ULECC) under the micro-mechanical design theory. Five lightweight ECCs were designed using different lightweight fillers (LF) and replacement ratios with three mix-tures being categorized as ULECC. The impacts of LF content and curing regimes (standard or hot-water curing) on the density, mechanical, and microstructural properties were investigated. The proposed ULECC exhibited impressive tensile behavior and a low density of 950-1260 kg/m3. The specific tensile strengths (strength-to-density ratio) and strain capacities of ULECC were 110% and 70% higher than conventional M45-ECC. Compared to the conventional LWECC, ULECC offered the competitive strength and ductility with a substantial increase in sustainability and reduction of material cost. Hot-water curing played a vital role in improving ductility-related performance. The micro-mechanical design theory and SEM analysis of ULECC well explained the test results. This research lays the groundwork for developing the sustainable and economical ULECC for future structural application.

Automated summary

This research aims to develop a novel sustainable and cost-effective ultra-lightweight engineered cementitious composite (ULECC) using the micro-mechanical design theory. Five lightweight ECCs were designed with different lightweight fillers (LF) and replacement ratios, and three mixtures were categorized as ULECC. The impacts of LF content and curing regimes on density, mechanical, and microstructural properties were investigated. This research lays the groundwork for developing the sustainable and economical ULECC for future structural applications.