Short and Continuous Carbon Fibers for Self-Monitoring Concrete Elements

Abstract

Abstract

The design and development of advanced, environmentally friendly, and sustainable concrete structures with integrated monitoring capabilities is one of the challenges of modern society. To address these challenges, the present study aims to investigate intelligent concrete elements by combining short and continuous fiber reinforcement platforms. Previous studies have employed either short, dispersed carbon fibers or continuous carbon yarns for self-monitoring applications in concrete elements. Each configuration serves distinct monitoring purposes and offers different structural capabilities. Short carbon fibers mainly enhance the electrical properties of the concrete matrix by achieving the percolation threshold, whereas continuous carbon yarns function as hybrid internal sensors. The use of short carbon fibers requires external measurement devices and lacks a main reinforcement system to carry tensile stress in the post cracking stage. Conversely, continuous carbon yarns, that are integrated within textile meshes, can serve both as the main reinforcement platform and as the sensory agents. These carbon-based textile reinforced concrete elements combine reinforcement with self-sensing capabilities, offering efficient and environmentally friendly solutions. However, their performance requires electrical connections at both ends to the data acquisition system and is highly dependent on the unique microstructural bond mechanism with the concrete matrix. The present study aims to overcome the limitations of individual technologies by developing self-sensory hybrid concrete structures that integrate both short and continuous carbon fibers. This concept leverages the synergy between the two reinforcement systems, enabling the hybrid elements to exhibit enhanced sensing performance, a broader range of monitoring capabilities, and improved structural behavior. Schematic demonstration of the new concept is presented in Fig. 1. In the proposed configuration, we aim to utilize the electrical properties of the carbon-based textile as a smart sensing device for the conductive concrete matrix. From a sensing perspective, this approach allows for a single electrical connection along the element, while from the structural perspective, the textile serves as the main reinforcement system. The study will demonstrate the advantages of this new concept through experimental investigation, designed to explore both mechanical electrical responses of the hybrid system under flexural and uniaxial tensile loadings. The outcomes of this study will provide valuable insights into the behavior of hybrid fiber systems and contribute to the development of efficient, intelligent concrete elements with integrated self-sensing capabilities.