Unstabilized and stabilized compressed earth blocks with partial incorporation of recycled aggregates

ABSTRACT

This article aims to characterize the physical, mechanical, and water-resistant behavior of unstabilized and stabilized compressed earth blocks (CEB) produced with partial incorporation of recycled fine aggregates from construction debris. The objective was to produce an alternative-earth construction material with lower embodied energy. To this end, different types of common CEB were covered, namely: unstabilized CEB; stabilized CEB with 8% cement; stabilized CEB with 4% cement and 4% lime. CEB were characterized in terms of density, thermal conductivity, compressive and tensile strength, water absorption, permeability, and resistance to water erosion from drip and spray tests. The influence of moisture content was also analyzed. Lime stabilization had little effect on the early age mechanical and durability behavior of CEB. Design coefficients are suggested for common cement-stabilized CEB under different environmental conditions. A minimum of 4% cement content was sufficient to produce water-resistant CEB with partial incorporation of recycled aggregates.

KEYWORDS:

• compressed earth blocks
• mechanical characterization
• recycled aggregate
• stabilization
• sustainability
• water resistance

Acknowledgments

The authors wish to thank CEris – ICIST/IST for funding the research, as well as the Architect Nuno Grealha and the city council of Montemor-o-Novo for their support in CEB production and for supplying the earth and recycled wastes used in the experiments.