TITLE:
Effect of Segregation on the Performance of 0/31.5 Granular Materials from the Kombe Deposit Used in Road Construction
AUTHORS:
Sylvain Ndinga Okina, Alain Symphorien Ndongo, Adoum Waibaye, Prince Mang Egrik W. O. Nkembo, Arsene Joseph Bockou Ekockaut, Louis Ahouet
KEYWORDS:
Granular Segregation, Material Sampling, Compactness, Intergranular Porosity, Segregation Particle Size Distribution
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.15 No.4,
November
3,
2025
ABSTRACT: The segregation of different particle sizes in a granular mixture leads to performance defects in construction materials. This article analyses the segregation of 0/31.5 crushed aggregates from the Kombe quarry used in road construction in Congo. The methodology consists of taking samples using various laboratory and field techniques (PD, DL, SCS, SCB, Q) likely to cause segregation. Data modeling using OriginPro2019b software consisted of deriving theoretical models to control segregation. The results obtained from the analysis of the descriptors of the particle size distribution curves (Cu > 2, Cc 3) and the fineness modulus (5% and 45%) show that the material studied is prone to granular segregation. The DL sampling model, with 44.54% fines and 37.16% gravel, corresponds well to the normative particle size distribution and appears to be the best for mitigating the effects of segregation. The theoretical DL model obtained by modeling gives an optimal granular composition, with 13.43% fine sand, 31.03% coarse sand, 37.16% gravel and 18.36% stones. The high percentages of fine elements in the material result in a 3.04% decrease in dry density for the SCB (Ds = 2.238 g/cm3) and Q (Ds = 2.170 g/cm3) samples. The SCB model has a high CBR (158.5%), indicating a mechanical improvement in the material. The presence of a granular class resulting from segregation affects the compactness of the material layer.