Abstract Concrete infrastructures increasingly face critical challenges, including electromagnetic interference (EMI)-induced corrosion, elevated energy demands, and ionizing radiation exposure, which undermine durability and resilience. This review synthesizes advancements integrating metamaterials, energy harvesting technologies, and radiation shielding into concrete systems. Metamaterial-enhanced concrete achieves EMI shielding effectiveness exceeding 99% absorption at GHz frequencies while mitigating corrosion in embedded steel reinforcement. Simultaneously, piezoelectric, triboelectric, and quantum dot-based composites enable ambient energy harvesting from mechanical, thermal, and solar sources, supporting self-powered structural health monitoring and smart cathodic protection systems. Advanced radiation-shielding concretes incorporating bismuth oxides, rare-earth additives, and multilayered architectures provide superior attenuation of gamma and neutron radiation while maintaining mechanical integrity. Beyond treating these three domains in isolation, this paper systematically identifies the shared material platforms (e.g., high-Z and carbon-based fillers, nanostructured binders) and common mechanisms (electromagnetic interaction, charge transport, and energy dissipation) that simultaneously govern shielding, harvesting, and radiation attenuation. The review provides a cross-domain comparison of design strategies, performance metrics, and durability issues, and maps explicit pathways for integrating multiple functionalities within a single concrete system. This review critically examines material innovations, performance mechanisms, experimental methodologies, and remaining gaps. It highlights the transformative potential of multifunctional concrete systems for sustainable, intelligent infrastructure, and identifies future research priorities spanning durability, life-cycle performance, and scalable manufacturing.
Abstract Built in 1356, the school, mosque, and mausoleum complex of Prince Sorghatmesh is a major Bahri Mamluk monument that has been affected by long-term environmental deterioration and undocumented interventions. This study presents an integrated diagnostic framework for structural assessment that combines three-dimensional (3D) laser scanning, nondestructive testing, laboratory testing, field measurements, and experimentally validated finite element modeling. High-resolution geometric data and measured mechanical properties were used to construct a numerical model calibrated against local in situ load testing, which showed good agreement between the numerical and measured responses, thereby supporting the reliability of the simulation framework. Under vertical loading, the courtyard arches were identified as the most critical structural components, exhibiting peak stresses of 4.17 MPa. However, under lateral loading, the minaret’s lateral displacement reached about 35 mm, and there was a clear concentration of stresses at the marble columns supporting the top of the minaret. Groundwater intrusion was found to reduce material mechanical properties by approximately 42%, accelerating localized deterioration in lower wall zones. Nevertheless, the global structural response remained within ranges typically observed for comparable historic masonry systems, indicating that only localized replacement of deteriorated elements is required. The proposed workflow provides a transferable and minimally invasive approach for evidence-based preservation and first-level structural assessment of historic structures.
Abstract A hybrid system of near surface–mounted carbon fiber–reinforced polymer (NSM-CFRP) and externally bonded CFRP has proven efficiency in improving and recovering the structural performance of the undamaged and damaged structural elements, especially when used for the RC flat slabs. The main objective of this research was to propose strengthening and repairing techniques to enhance the punching shear performance of RC flat slabs. Specifically, a hybrid system of CFRP ropes embedded through an intact and preloaded RC flat slab surface and then anchored by CFRP sheets was used to investigate its efficiency in enhancing and restoring the structural properties of the undamaged and damaged flat slabs. Nine square RC flat slabs with 1,000-mm side length and 120-mm width were cast using normal-weight concrete with a compressive strength of about 26 MPa. The specimens were used as follows: one specimen was used as a control specimen, four specimens were strengthened using vertical and inclined CFRP ropes embedded through the flat surface anchored by CFRP sheets, and four specimens were preloaded up to 50% of the ultimate capacity of the control specimen and then repaired using vertical and inclined CFRP ropes embedded through the flat surface anchored by CFRP sheets. Test results indicated that the use of a hybrid system can improve the structural performance and punching shear behavior of RC flat slabs, whether undamaged ones or damaged by preloading. Additionally, the most effective strengthening technique in terms of improving the ultimate capacity of the flat slab was to apply the CFRP ropes inside the concrete surface vertically on both punching perimeters anchored by CFRP sheets; with this system, the ultimate capacity increased by 66.2%, whereas applying the same strengthening technique on the first punching perimeter only increased the stiffness, by 23.2%. The same performance was observed for the preloaded specimens, but when applying the rope with an inclination inside the flat slab, the percentage increase in the ultimate capacity when applying the repairing technique on both punching perimeters was 84.4%, and 14.2% increase was recorded in stiffness when applying the repairing technique on the first perimeter only. The use of the hybrid repairing and strengthening technique contributed to enhancing the failure mode performance of the flat slab; all specimens exhibited a debonding failure of the CFRP sheets, followed by a concrete cover separation.
Abstract Structural analysis and design of a reinforced concrete (RC) beam satisfying a reliable serviceability criterion demand precise calculation of the effective modulus of elasticity ( E RCC ) of a beam. Various international codes suggest an empirical equation for the modulus of elasticity of concrete ( E c ) dependent on the compressive strength of concrete ( f c k ) alone. However, real-life buildings are of RC material and not concrete only. The current study was undertaken to represent a simplified method to evaluate E RCC for doubly RC beams by developing empirical correction factors and design charts resulting entirely from experimental data. Six beams of a cross-section 250 mm × 500 mm × 2,100 mm for M35 concrete grade were tested, subjected to two-point loading. The reinforcement for a beam specimen was varied in the range of 0.193% to 0.535%. The regression analysis was carried out to express a compact equation of E RCC dependent on f c k , tension reinforcement ( p t ), and compression reinforcement ( p c ). A dimensionless correction factor ( k = E RCC / E c ) and a design chart for the M35 grade of concrete were calculated and plotted. The correction factor was found to be between 1.05 and 1.30 for beams with a reinforcement ratio ( ρ = p t / p c ) in the range of 0.2 to 0.55. The modified approach resulted in 15%–25% reduction in deflections due to serviceability loads that the conventional code estimates. Results indicate that stiffness correction increases systematically with reinforcement percentage, leading to improved prediction of beam deflection and serviceability response. The deflection reduction was recorded strictly adhering to reinforcement ratios, beam dimensions, and loading levels undertaken in the study. The charts are therefore recommended for use within the calibrated parameter domain and should not be extrapolated beyond the validated limits.
Abstract The design method for slender fiber-reinforced polymer (FRP) reinforced concrete (FRP-RC) rectangular columns based on the nominal curvature is not yet included in the new Eurocode 2 Annexure R. However, a proposal to expand Eurocode 2 in this regard is presently being considered and would also be included in the new DAfStb guideline for nonmetallic reinforcement. Additionally, other national codes, such as ACI 440.11-22 and CSA S806-12, also require load–moment capacity curves for the design of FRP-RC column cross sections. However, distinct load–moment capacity curves are required for each type of FRP bar in FRP-RC columns due to their different modulus of elasticity and ultimate design strain limits. This paper presents a novel concept of universal interaction diagrams, which can be used regardless of the type of FRP reinforcement bar such as glass, carbon, basalt, or aramid FRP. This significantly enhances both its usability and practicality in structural design. These diagrams only depend on the concrete strength, reinforcement configuration, and cover-to-depth ratio. This paper introduces provisions to expand Eurocode 2, provides universal interaction diagrams for rectangular cross sections for cross-section design, and provides universal interaction diagrams for slender FRP-RC columns with slenderness ratios of 40, 60, and 80, all of which are based on the nominal curvature method. The universal interaction diagrams for slender columns bypass the iterative solution of the presented equations and therefore have high practical value. Finally, the paper provides three worked examples that illustrate how to analyze and design short and slender FRP-RC columns using the presented diagrams.
