Axial Compression and Flexural Strength of Compacted Adobe with the Addition of 6%, 8%, and 10% Cassava Starch, Cajamarca 2025

Abstract

The primary objective of this research was to analyze and determine the influence of cassava starch as an organic stabilizing agent on the axial compressive and flexural performance of compacted adobe blocks, based on the classification of soils suitable for the manufacture of such units. Soil classification tests identified a granulometrically suitable material for the proper production of this composite, to which cassava starch was incorporated as a particle stabilizer in proportions of 6%, 8%, and 10% by weight of the block. The specimens were compacted using the BRICK BLOCK machine (an electromechanical system enhanced by Mr. Juan Montoya) in order to evaluate the effects of the additive on axial compressive strength in comparison with the values established by standards E.080 (MVCS, 2021) and UNE 41410 (2008), which specify minimum strengths of 10.2 kg/cm2 and 13.26 kg/cm2, respectively. Additionally, axial compressive and flexural strengths were compared with those obtained from conventional earth adobe blocks compacted under identical conditions using the same machine, which exhibited an average compressive strength of 33.09 kg/cm2. Specifically, values of 20.02 kg/cm2, 32.62 kg/cm2, and 37.37 kg/cm2 were recorded for the 6%, 8%, and 10% additions, respectively. These results exceed the minimum requirements prescribed by the standards by up to threefold and represent an increase of approximately 10% relative to conventional earth adobe compacted using the BRICK BLOCK machine. Furthermore, flexural strength results for specimens containing 10% cassava starch were also superior, reaching 5.10 kg/cm2, compared to 4.88 kg/cm2 for conventional earth adobe.