Response Surface Method Analysis of Chemically Stabilized Fiber-Reinforced Soil.

Abdullah Almajed,Dinesh Srirama,Arif Ali Baig Moghal

doi:10.3390/ma14061535

Abdullah Almajed, Dinesh Srirama + Show 1 more

Open Access

https://doi.org/10.3390/ma14061535

Copy DOI

Abstract

One of the significant issues persisting in the study of soil stabilization is the establishment of the optimum proportions of the quantity of stabilizer to be added to the soil. Determining optimum solutions or the most feasible remedies for the utilization of stabilizing products in terms of their dose rates has become a significant concern in major civil engineering design projects. Using the response surface methodology, this study primarily focused on investigating the optimal levels of reinforcement fiber length (FL), fiber dosage (FD), and curing time (CT) for geotechnical parameters of stabilized soil. To realize this objective, an experimental study was undertaken on the California bearing ratio (CBR) and unconfined compressive strength (UCS). Hydraulic conductivity (HC) tests were also performed, with stabilizer proportions of 6–12 mm for the FL and 0.2–0.6% for the FD calculated for the total dry weight of soil and 6% lime (total weight of dry soil). The curing times used for testing were 0, 7, and 14 days for the CBR tests; 60, 210, and 360 days for the UCS tests; and 7, 17, and 28 days for the HC tests. All practical experiments were conducted with experimental techniques using stabilizer proportions and curing times. The FL, FD, CT, CBR, UCS, and HC response factors were determined using the central composite design. The results point toward a statistically significant model constructed (p ≤ 0.05) using the analysis of variance. The results from this optimization procedure show that the optimal values for the FL, FD, and CT were 11.1 mm, 0.5%, and 13.2 days, respectively, as these provided the maximum values for the CBR; 11.7 mm for the FL, 0.3% for the FD, and 160 days for the CT corresponded to the maximum values for the UCS; and 10.5 mm for the FL, 0.5% for the FD, and 15 days for the CT led to the minimum value for the HC. In practice, the suggested values may be useful for experiments, especially for preliminary assessments prior to stabilization.

Highlights

Site feasibility is the major hindrance in most civil engineering projects
The present study examined the determination of input variables that could potentially offer the optimum values of various geotechnical parameters, such as the unconfined compression strength (UCS), hydraulic conductivity (HC), and California bearing ratio, through optimization using face-centered central composite design (FCCCD) in conjunction with an response surface methodology (RSM) study of regular expansive semi-arid soil from the municipality of Al-Ghat
With an increase in curing period, the Hydraulic conductivity (HC) values were reduced significantly, which can be attributed to the formation of cementitious compounds due to the addition of lime, making the treated soil less conductive

Summary

Introduction

In the majority of civil engineering projects worldwide, expansive soils have substantial geotechnical and structural design-related issues, with economic difficulties estimated to entail costs of several billion dollars annually [1,2,3]. Recent advances have shown a rising interest in chemical and bio-geochemical alterations of soils hat enhance their geotechnical properties [5,7] Among these methods, lime stabilization is the most sought after technique due to its versatility and innate potential in addressing the distress-related issues of expansive plastic fines [8,9,10,11]. When amended with the soil medium, polypropylene fiber materials demonstrate proven functionality in durability and sustain soil index and engineering properties improvements in the long run [14,15]

Methods

Results

Conclusion