DOI: 10.11648/j.ijaaa.20261202.14 ISSN: 2472-1131

Reliability Analysis and Performance Comparison of SP430-stabilized Lateritic-soil Concrete Beams Using FORM

Abu Omolegho, John Wasiu, Ibrahim Olayinka
Show PDF Cite
Utilizing lateritic soil from Iyamho, Edo State, Nigeria, as the base material, this study examines the probabilistic reliability and mechanical performance of reinforced and unreinforced concrete beams stabilized with sulphonate naphthalene-formaldehyde (SNF) super plasticizer (SP430) at dosages of 0%, 2.5%, 5%, and 7.5%. At curing ages of 7, 14, 21, and 28 days, flexural strength tests were conducted on prismatic beams (500 × 100 × 100 mm) that were reinforced with 10 mm stirrups and 12 mm longitudinal bars. To evaluate safety margins, the First Order Reliability Method (FORM) was utilized, which produced reliability indices (β) based on stochastic variables such as reinforcement properties, modulus of rupture (MoR, N/mm 2 ), and failure load (F, kN). The results demonstrate that reinforced beams outperformed unreinforced beams in terms of failure loads (4.202–4.255 kN) and MoR (3.15–3.19 N/mm 2 ) with SP430 considerably increasing strength, especially in unreinforced beams where a 7.5% dosage increased F by 12% as opposed to 1.2% in reinforced beams. Although high SP dosages somewhat decreased β because of slight matrix variability, unreinforced beams showed higher β (9.03–9.15) than reinforced beams (8.75–8.76), indicating simpler failure modes. While β values significantly surpass Eurocode targets (3.5–4.5), indicating overly conservative designs that can be optimized, the constant coefficient of variation (10%) across all beams indicates stable material properties. By lowering the cement content and increasing early-age strength, SP430 enhanced workability and matrix density, promoting sustainable design. With suggestions for more research into dosage optimization and long-term durability, these findings highlight the potential of SP430 in optimizing lateritic soil-based concrete for economical, dependable, and ecologically friendly geotechnical and structural applications in tropical regions.

More from our Archive