Flexural Strength Characteristics of Fiber-Reinforced Cemented Soil

Abstract

This work deals with the flexural performance of a soil-cement for pavement reinforced by polypropylene and steel fibers, and the main purpose is to evaluate the effect of different curing times. In this sense, three different curing times were employed to investigate the influence of fibers on the material’s behavior at varying levels of strength and stiffness as the matrix became increasingly rigid. An experimental program was developed to analyze the effects of incorporating different fibers in a cemented matrix for pavement applications. Polypropylene and steel fibers were used at 0.5/1.0/1.5% fractions by volume for three different curing times (3/7/28 days) to assess the fiber effect in the cemented soil (CS) matrices throughout time. An evaluation of the material performance was carried out using the 4-Point Flexural Test. The results show that steel fibers with 1.0% content improved by approximately 20% in terms of initial strength and peak strength at small deflections without interfering the flexural static modulus of the material. The polypropylene fiber mixtures had better performance in terms of ductility index reaching values varying from 50 to 120, an increase of approximately 40% in residual strength, and improved cracking control at large deflections. The current study shows that fibers significantly affect the mechanical performance of CSF. Thus, the overall performance presented in this study is useful for selecting the most suitable fiber type corresponding to the different mechanisms as a function of curing time.

Review of Subgrade Soil Stabilised with Natural and Synthetic Fibres

“…The material was evaluated using 4-point flexural test. According to Pedroso et al (2023), the results show that 1.0% steel fibres improved the initial strength and peak strength at low deflection. However, the polypropylene fibre mixtures showed better performance achieving ductility index reaching, residual strength, and improved crack control at large deflections.…”

“…This approach aims to optimize the mechanical performance of the soil in a target region. For this reason, the probability of failure surfaces is relatively higher in unreinforced regions (Pedroso et al, 2023;Rao & Naidu, 2019;Yazici & Keskin, 2021). With this method, the fibres are randomly distributed in the soil.…”

“…The aim of Randomly Distributed Fibre Reinforcement Soil (RDFRS) is to improve the overall mechanical properties of the soil by providing strength and cohesion in different directions. This approach is useful when the stresses acting on the soil can come from multiple directions or when the stress distribution is unpredictable (Pedroso et al, 2023;Rao & Naidu, 2019;Yazici & Keskin, 2021).…”

“…Subgrade soil stabilisation using steel fibre is a construction technique in which steel fibres are incorporated into subgrade soils to improve their strength, durability and loadbearing capacity Steel fibres are typically small, discontinuous strands or particles made from various types of steel, including carbon steel and stainless steel (Hejazi et al, 2012;Marcalíková et al, 2019;Yan et al, 2021). Pedroso et al (2023) conducted a study to evaluate the influence of different curing times on the flexural performance of a soil cement for pavements reinforced with polypropylene fibres and steel fibres. Polypropylene fibres and steel fibres were used individually in volume proportions of 0.5%, 1.0%, and 1.5% of weight of soil for three different curing times (3, 7, and 28) days.…”

Dynamic mechanical properties of ferronickel slag powder-modified soil-cement using split-hopkinson pressure bar testing

“…In fact, many researchers have attempted to add various types of waste materials to concrete, investigating changes in their mechanical properties or deformation characteristics [5], such as fly ash [6,7], ferronickel slag [8,9], fibers [10], gypsum [11], steel slag [12], and coal gangue [13]. However, there have been fewer instances of applying these materials in soil-cement.…”