International Journal of Structural Engineering (5 papers in press)

Regular Issues

• Preventive and corrective strategies and action plans for concrete repair: lessons learned from a concrete structural defect at a steam power plant  
  by Jason Lim, Prima Ranna, Elia Oey 
  Abstract: Mass concrete, commonly used in power plant construction, often faces issues from temperature rise during cement hydration. This can lead to defects such as honeycombs (voids or air pockets), cracks, and cold joints (weak bonding between concrete batches). These defects may compromise structural integrity and reduce the efficiency of power plants, potentially causing financial losses. This study explores these challenges using a case from a steam power plant (PLTU) in Indonesia. It applies fault tree analysis (FTA), failure mode and effect analysis (FMEA), and analogies from simultaneous importance performance analysis (SIPA) to determine root causes and propose preventive strategies. Additionally, corrective actions are suggested through forensic assessment following American Concrete Institute (ACI) standards. The research underscores the need for controlled hydration and proper repair methods. It provides an in-depth approach to managing concrete defects in large infrastructure projects, aiming to improve construction quality and long term performance.
  Keywords: mass concrete; fault tree analysis; FTA; failure mode and effect analysis; FMEA; simultaneous importance performance analysis; SIPA; risk priority number; RPN.
  DOI: 10.1504/IJSTRUCTE.2025.10072406
   
  
• Evaluation of deflection amplification factor for steel structures containing linked-columns-frame system under seismic scenarios with/without sequences of earthquakes  
  by Yaser Golestani, Elham Rajabi, Reza Rajabi Soheyli 
  Abstract: Since the linked-columns-frame (LCF) system is a relatively novel dual lateral force resisting system, numerous seismic examinations still remains essential. This paper examines the deflection amplification factor (Cd) of LCFs. To this end, 31-LCF structures were subjected to linear/nonlinear dynamic and static analysis. Then Cd and Cd/R were obtained based on the length, behaviour of the shear/flexural link beam and the strain hardening ratio of the columns. Moreover, due to the high damage potential of successive earthquakes, the effects of critical seismic sequences were particularly investigated. After performing over 5,000 nonlinear analysis, the results indicated the variation of Cd factor in the height, its dependency on the flexural/shear behaviour, and the link beam length, as well as the negligible effect of the seismic sequences compared to single earthquakes on the average of Cd factor. A value between 6.5~10.0 was proposed for Cd factor of the typical buildings containing LCFs.
  Keywords: deflection amplification factor; Cd; linked-columns-frame; LCF; critical seismic sequences; nonlinear dynamic analysis.
  DOI: 10.1504/IJSTRUCTE.2025.10072509
   
  
• Double viscous dampers for seismic response control of tall building  
  by Bhargav Shashikant Raval, Snehal Vasantlal Mevada 
  Abstract: The increasing demand for urban infrastructure has led to the proliferation of tall buildings. Viscous dampers are adopted as passive control system to mitigate structural vibrations due to natural hazards. This study introduces and explores the effectiveness of an innovative passive damper, the single-cylinder double viscous damper (DVD) by modifying conventional viscous damper (CVD) in mitigating the seismic responses. A 25-storey tall reinforced concrete building is 3D modelled and designed in ETABS and uncontrolled responses analysed under six real ground motion. With optimised value of damping coefficient, the controlled responses are derived in MATLAB using state space method with comparison made, both in linear and nonlinear configurations. Two damper arrangement schemes are explored: scheme 1 (all-storey dampers) and the proposed scheme 2 (alternate-storey dampers) in staggered configuration, such that each damper connects non-consecutive storey by skipping immediate storey in between. Effectiveness of each damper configuration is evaluated using derived controllability index (Re). The controlled responses include, top storey displacement, top storey acceleration, storey drift, storey acceleration, base shear and damper forces are compared with uncontrolled one. Numerical comparison shows that DVDs and scheme 2 provide superior seismic response control and offer a more economical solution than CVDs, highlighting the potential of advanced damping technology.
  Keywords: seismic response; optimum; double viscous damper; linear and nonlinear viscous damper; state space method; numerical simulation; MATLAB.
  DOI: 10.1504/IJSTRUCTE.2025.10072579
   
  
• Strength and bonding characteristics of mortar with recycled sand from construction and demolition wastes  
  by Kumutha Rathinam, Prathiba Shanmugavel, Monica Varadharaj 
  Abstract: Administration of construction and demolition (C&D) wastes has been gaining attention and its implementation will be considered successful when there is a market appreciation for the products processed from such wastes. Government of India is taking initiatives and released guidelines and policies and green building rating schemes to advance the usage of recycled products. An insight of inferiority due to insufficient and reliable data on the performance of the reclaimed products was identified as drawbacks that hamper its usages. Through the present exploration, it was attempted to develop a cement-based mortar using fine aggregates derived from demolition wastes that could be possibly used for repairing the existing deteriorated concrete buildings. Three mortar mixes were evaluated using cement, M-sand and recycled sand for their flow properties together with their strength, absorption and bonding characteristics. The results obtained are presented and discussed.
  Keywords: C&D wastes; mortar; fine aggregates; flow; strength; water absorption; bond strength.
  DOI: 10.1504/IJSTRUCTE.2025.10072953
   
  
• Experimental investigation of moment carrying capacity of cellular beam in view of lateral distortional buckling  
  by Bhagyashree Mali, Athar Jamadar, Hanmant Jadhav 
  Abstract: Castellated beams with circular openings are increasingly popular in modern engineering for their structural benefits and aesthetic appeal. However, they often suffer from lateral distortional buckling due to their increased web depth. While research has focused on hexagonal openings, there is a lack of studies on circular openings. This paper investigates the buckling behaviour of cellular beams with circular openings through experiments and finite element modelling. A parametric study assesses the impact of S/Do (spacing to depth of opening) and D/Do (overall depth to depth of opening) ratios on buckling. Results indicate that increasing the S/Do ratio significantly improves the beams failure load, enhancing buckling resistance. The D/Do ratio also influences failure load but is less significant, especially at higher S/Do values. Cellular beams with opening ratio S/Do = 1.4 and D/Do = 1.45 provide optimal structural efficiency, emphasising the S/Do ratio as crucial for improving buckling strength.
  Keywords: castellated beam; cellular beam; lateral distortional buckling; finite element modelling.
  DOI: 10.1504/IJSTRUCTE.2025.10073004