COMPARISON OF THE DENSITY OF SANDY SOIL BY ADDING PINE SEED ASH (3%, 6% AND 9%), BY PROCTOR TEST

Abstract

This experimental study evaluated the effect of adding pine seed ash (pine nuts) at percentages of 3%, 6%, and 9% on the dry density of a sandy soil using the modified Proctor test. The research stems from the need to find sustainable alternatives in civil engineering that allow for the utilization of plant residues and improve soil performance. The main objective was to determine how the density of sandy soil changes with the incorporation of pine nut ash and to evaluate its potential as a stabilization alternative. The study was conducted using a quantitative approach, employing 16 samples distributed into four experimental groups (0%, 3%, 6%, and 9% ash). The tests were performed according to the NTP 339.141 / ASTM D1557 standard, compacting each mixture in five layers and determining the maximum dry density and optimum moisture content from the resulting compaction curves. The results showed that the average dry density decreased with incorporation: 1.85 g/cm3 without ash, 1.78 g/cm3 with 3%, 1.67 g/cm3 with 6%, and 1.57 g/cm3 with 9%. This demonstrates that in the studied soil, pine nut ash does not improve compaction but rather reduces its capacity to achieve higher density values. It is interpreted that the interaction between the ash and the soil particles can alter the granular structure of the material, affecting how the particles arrange themselves during compaction. Therefore, determining the proportion of lignocellulosic residues is fundamental in sustainable geotechnical applications.