Effect of a 90-day Curing Time on the Mechanical Properties of Stabilized Compressed Earth Blocks Reinforced with Banana Trunk Powder

Abstract

In the context of combating climate change and reducing the carbon footprint of the construction sector, this study focuses on the evaluation of the mechanical performance of Stabilized Compressed Earth Blocks (SCEB) incorporating banana trunk powder (BTP) as a partial alternative to cement. The main objective is to analyze the impact of an extended curing time of 90 days on the mechanical strength of laboratory-made SCEBs. Two formulations were studied: earth + sand + BTP and earth + sand + cement, with stabilizer dosages ranging from 2% to 10% and a water content between 9% and 14%. The results show that the formulation with 2% BTP and 13% water offers the best mechanical performances after 90 days of curing, reaching 1.89 ± 0.01 MPa in flexion and 6.84 ± 0.12 MPa in compression, a significant improvement compared to the performances observed at 28 days (0.82 ± 0.10 MPa in flexion and 3.91 ± 0.58 MPa in compression). On the other hand, an increase in the BTP rate beyond 2% leads to a significant decrease in strength. Conversely, cement-based formulations exhibit a linear performance evolution, reaching 4.02 ± 0.07 MPa in flexure and 18.77 ± 0.36 MPa in compression at 10% cement and 13% water, compared to 2.59 ± 0.31 MPa and 12.32 ± 0.66 MPa respectively at 28 days. This study demonstrates that the use of 2% BTP with a 90-day curing time is an optimal solution, combining mechanical efficiency, low environmental impact and the recovery of agricultural waste, thus contributing to the promotion of sustainable and ecological construction materials.