International Journal of Structural Engineering (4 papers in press)

Regular Issues

• Evaluation of the performance of seismically strengthened and prestressed exterior beam-column joints  
  by Pradeep M. Yeole, Yogesh D. Patil, Yuvaraj L. Bhirud 
  Abstract: Reinforced concrete (RC) beam-column joints (BCJs) are crucial in moment-resisting frames but are vulnerable to seismic damage. This study introduces a novel external diagonal prestressing technique using high-strength steel strands to improve the seismic performance of ductile-detailed exterior BCJs. The method is minimally invasive, cost-effective, and requires minor structural changes. Six full-scale BCJ specimens were tested under reverse cyclic loading: one control and five with varying prestressing levels (040%). The specimen prestressed at 30% showed a 70.37% increase in ultimate load and a 263% rise in initial stiffness. Prestressed joints had slower stiffness degradation and greater energy dissipation in early cycles. The failure mode shifted from brittle joint shear to ductile beam flexure, enhancing seismic resilience. The diagonal prestressing induced axial compression in the beam, improving joint shear strength. Overall, the technique provides a practical and effective alternative to traditional retrofitting methods for enhancing earthquake resistance in RC joints.
  Keywords: reinforced concrete; prestressing; hysteretic behaviour; energy dissipation; flexibility; stiffness; retrofitting; seismic performance.
  DOI: 10.1504/IJSTRUCTE.2026.10076736
   
  
• Tri-waste geobrick innovation: performance evaluation of earth bricks over laterite, crushed palm seed, and rice husk ash  
  by K. Chithra, M. Bhuvaneshwari 
  Abstract: Climate change, escalating construction demand, and increasing resource scarcity have intensified the need for sustainable and low-cost building materials, particularly in climate-vulnerable regions. Conventional fired clay bricks are energy-intensive, non-renewable, and associated with high greenhouse gas emissions, while offering limited thermal resistance and environmental adaptability. Addressing these limitations, this study proposes a novel tri-waste geo-brick formulated using laterite, crushed palm seed (CPS), and rice husk ash (RHA) as an unfired compressed stabilised earth brick (CSEB). Five mix combinations were developed using Taguchi experimental design and evaluated through ASTM/EN standards, supported by SEM, XRD, FTIR, life-cycle assessment, and cost-benefit analysis. Results indicate that mix 4 and mix 5 achieved optimal performance, with 5.4 MPa compressive strength, 1.21 W/m
  Keywords: compressed stabilised earth brick; CSEB; rice husk ash; RHA; crushed palm seed; CPS; laterite; sustainable building material; thermal conductivity; SEM; XRD; life-cycle assessment; LCA; cost-benefit analysis.
  DOI: 10.1504/IJSTRUCTE.2026.10077245
   
  
• Compressed steel fibre-reinforced concrete slab in joint of steel-concrete composite frame structure  
  by Petr Červenka, Jakub Dolejš 
  Abstract: This paper deals with a steel fibre-reinforced concrete (SFRC) slab in compression as a composite steel-concrete frame joint component. Based on the results of an experiment with a realistic-sized steel-concrete specimen, a numerical model has been validated in Atena Science. Based on a parametric study with these models, an analytical relationship was derived for the resistance and stiffness of the steel fibre-reinforced concrete slab in compression. In contrast to the standard procedure given in Annex C of EN 1998-1:2004 (Eurocode 8), the new procedure is designed for a steel fibre-reinforced concrete slab. The proposed analytical solutions give approximately 20% higher values of the resistance and initial stiffness factor than the results calculated according to EN 1998-1:2004 (Eurocode 8) and EN 1993-1-8:2005 (Eurocode 3).
  Keywords: composite steel-concrete frame; steel fibre-reinforced concrete; SFRC; composite steel-concrete joint; slab in compression; effective width; earthquake; FEM.
  DOI: 10.1504/IJSTRUCTE.2026.10077685
   
  
• Microbially induced carbonate precipitation for soil improvement: factorial analysis, shear testing and characterisation  
  by K. Prakash Chandra, Joga Suryaprakash Reddy, K. Mallikarjuna Rao 
  Abstract: Soil improvement utilising microbially induced calcite precipitation technologies is currently attracting a lot of attention in the geo-environmental and geotechnical fields. The purpose of this study is to evaluate how critical parameters influence calcite precipitation, and ensuing improvement in the mechanical characteristics of very loose fine sand. The impact of curing period, soil saturation level, and cementation solution molarity on calcite precipitation are evaluated using a 24 factorial experimentation design. Direct shear tests were conducted to evaluate strength and deformation characteristics. Microstructural characterisation was performed using scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction. The effect of any given factor is influenced by the level of other factors indicating that interaction effects also influence calcite produced. MICP offers a promising avenue to address soil. Related challenges while reducing the environmental impact of traditional stabilisation methods as demand for environmentally conscious soil stabilisation techniques grows.
  Keywords: MICP; saturation ratio; optical density; cementation molarity; curing period.
  DOI: 10.1504/IJSTRUCTE.2026.10077709