Effect of Varying Curing Conditions on the Strength of Biopolymer Modified Sand

Abstract

Recently, the improvement of the engineering properties of soil has been centered on using sustainable and eco-friendly materials. This study investigates the efficacy of three biopolymers: Acacia, sodium alginate, and pectin, on the unconfined compressive strength (UCS) of dune sand. The UCS test measured the effects of the biopolymer type and concentration, curing intervals and temperature, and moisture loss. The changes in the morphology caused by the biopolymer addition were examined via scanning electron microscopy (SEM). Results indicate that the UCS of the biopolymer-modified sand increased with biopolymer concentration and curing intervals. Varying the curing temperature from 25–110 °C, slightly affected the strength of the acacia-modified sand specimen, increased that of the sodium alginate-modified sand specimen up to a temperature of 85 °C, and continued to decrease that of the pectin-modified sand specimen as the temperature was increased from 25 to 110 °C. The SEM images indicated that the biopolymer’s presence within the sand pores significantly contributed to the strength. Bond decomposition occurs at temperatures greater than 110 °C for sodium alginate and pectin-modified sands, whereas bonds remain stable at higher temperatures for the acacia-modified sand. In conclusion, all three biopolymers show potential as robust and economic dune stabilisers.

Rock‐like strength enhancement of Indian desert sand using commercially available polysaccharide biopolymers

“…By comparing 1 PV and 0.75 PV, it was found that in the case of AG, 0.75 PV was almost twice as strong as 1PV. In the case of SA and P, the values increased with increasing percentage of biopolymer (Lemboye & Almajed, 2023).…”

A Review on Soils Treated with Biopolymers Based on Unsaturated Soil Theory

“…Curing age is an important factor affecting the strength of improved soils [42]. The curing age generally ranges from 0 to 60 days, and the curing time plays a key role in improving the strength and deformation resistance of the improved soil [55]. In this period, the differences of various improved soils are relatively significant, and there is an optimal curing age.…”

“…The linear relationships of E50-UCS and UCS-TS were obtained, which are closely related to temperature. Lemboye et al [55] studied the effects of sodium alginate and pectin on the unconfined compressive strength (UCS) of sand. The UCS test measured the effects of the biopolymer type and concentration, curing interval and temperature, and water loss.…”

Freeze-Dried β-Glucan and Poly-γ-glutamic Acid: An Efficient Stabilizer to Strengthen Subgrades of Low Compressible Fine-Grained Soils with Varying Curing Periods

“…The addition of lignin to CL soil resulted in a reduction in the effective angle of shearing resistance and an enhancement of effective cohesion by 22.1% and 120.8% [ 6 ]. Lemboye and Almajed [ 7 ] improved the UCS of pectin-stabilized sandy soil by 137-fold and attributed the strength gain to the loss in the moisture of the stabilized sand. Hamza et al [ 8 ] evaluated the long-term strengthening effect of a problematic swelling clay on treatment with guar gum biopolymer and noted a linear increase in strength with the curing period, with the UCS attaining 654 kN/m 2 after 365 days.…”