PERFORMANCE OPTIMIZATION OF SUSTAINABLE RAMMED EARTH BLOCKS REINFORCED WITH JUTE AND LIMESTONE CALCINED CLAY CEMENT (LC3)

Abstract

Rammed earth blocks (REBs) are attracting renewed attention as sustainable building materials due to their low embodied energy and use of locally sourced soil, yet their limited tensile strength and moisture sensitivity restrict wider structural applications. This study investigates a dual enhancement approach, combining natural jute fiber reinforcement (0.25–1.25% by weight) with 10% Limestone Calcined Clay Cement (LC3) stabilization. To evaluate performance, mechanical tests—including compaction, compressive strength (dry and wet), flexural strength, ultrasonic pulse velocity (UPV), and water absorption—were performed. Microstructural evolution was examined through binocular microscopy, FESEM-EDS, XRD, and TGA analyses. Results indicated that 1% jute fiber provided the best balance of strength and ductility, while LC3 contributed to matrix densification and improved durability. The combined system achieved a compressive strength of 4.32 MPa, a flexural strength of 1.17 MPa, and reduced water absorption to 13.18%. Microstructural observations confirmed the formation of pozzolanic products and a refined pore network, highlighting the potential of this composite for durable, low-carbon, and cost-effective construction.