FRP Design Methodology and Applications for Blast and Impact-Resistant Structures-Considerations for Design of FRP Retrofitted Walls and Slabs Subjected to Blast Loading (PDF)

Considerations for Design of FRP Retrofitted Walls and Slabs Subjected to Blast Loading (PDF)

Pdf Summary

This document explores the design considerations for Fiber Reinforced Polymer (FRP) retrofitted reinforced concrete (RC) walls and slabs subject to blast loading. The motivation stems from the need to protect civilian infrastructure against unsustainable catastrophic failures, such as those seen in major incidents in Lac-Mégantic (Canada), Oslo (Norway), and Oklahoma City (USA).<br /><br />FRP materials offer advantages such as high strength-to-weight ratios, chemical and electrical inertness, durability, low maintenance costs, and cost-effectiveness. They are especially useful for retrofitting and rehabilitating structures affected by seismic deficiencies or corrosion.<br /><br />The report aims to analyze FRP's effectiveness in enhancing the blast resistance of RC walls and slabs using experimental data derived from testing with a Shock Tube. The study deploys Carbon Fiber Reinforced Polymers (CFRP) on the tension face of test specimens with varying thicknesses (80 mm and 120 mm) and configurations (control, retrofitted layers, and FRP anchors).<br /><br />Key elements of the experimental program reveal that FRP enhances the blast resistance by increasing the structural elements' strength and stiffness, and significantly reducing maximum displacements. In terms of performance, FRP anchors help control premature debonding and improve failure thresholds under stress. However, the study acknowledges that anchor rupture due to stress concentrations could occur.<br /><br />Additionally, considerations regarding moment reversal—the backward movement of structural components after being forced forward by blast pressure—are emphasized. The document suggests strengthening both the inbound and rebound faces of structures to mitigate failures arising from such dynamics.<br /><br />Overall, the research concludes that FRP retrofitting effectively improves a structure's resistive capacity against blasts. Recommendations include the strategic use of mechanical anchorage and enhancement of outbound surfaces in tandem with inbound reinforcements to augment FRP retrofitting strategies effectively.

Keywords

Fiber Reinforced Polymer

retrofitting

reinforced concrete

blast loading

CFRP

shock tube testing

structural strength

moment reversal

mechanical anchorage

resistive capacity