Deterioration of Basic Properties of the Materials in FRP-Strengthening RC Structures under Ultraviolet Exposure

This paper presents an experimental study of the basic properties of the main materials found in reinforced concrete (RC) structures strengthened by fibre reinforced polymer (FRP) sheets with scope to investigate the effect of ultraviolet (UV) exposure on the degradation of FRP, resin adhesive materials and concrete. The comparison studies focused on the physical change and mechanical properties of FRP sheet, and resin adhesive materials and concrete before and after UV exposure. However, the degradation mechanisms of the materials under UV exposure were not analyzed. The results show that the ultimate tensile strength and modulus of FRP sheets decrease with UV exposure time and the main degradation of FRP-strengthened RC structures is dependent on the degradation of resin adhesive materials. The increase in the number of FRP layers cannot help to reduce the effect of UV exposure on the performance of these materials. However, it was verified that carbon FRP materials have a relatively stable strength and elastic modulus, and the improvement of the compression strength of concrete was also observed after UV exposure

Behaviour of Circular Fiber-Reinforced Polymer-Steel-Confined Concrete Columns Subjected to Reversed Cyclic Loads: Experimental Studies and FE Analysis

This paper studies experimentally the behaviour of circular FRP-steel-confined columns subjected to reversed cyclic loads. The influence of main structural factors on the cyclic behaviour of the columns is discussed. Test results show the outstanding seismic performance of FRP-steel confined reinforced concrete (RC) and steel-reinforced concrete (SRC) column. The lateral confinement effectiveness of FRP materials is verified in the steel tube confined RC columns. A simplified finite element method (FEM) model supported by OpenSees is developed to simulate the experimental results of the test columns. Based on the proposed FEM model, a parametric analysis is conducted for investigating the effects of several main factors on the reversed cyclic behaviour of GFRP-steel confined RC columns. Based on the test and numerical analyses, the study discusses the influence of variables such as the lateral confinement on the plastic hinge region and peak drift ratio of the studied concrete columns under reversed cyclic loads. Results indicate that the lateral confinement significantly affects the height of plastic hinge region of circular confined columns without H-steel. Based on the analysies of test data from the study and literature, the paper suggests a simple model to predict the peak drift ratio of the confined RC columns

Actes de la conférence RUGC2018

International audienc

Seismic Damage Assessment Indexes for Masonry Structures

International audienc

A new PCM-TRC composite: A mechanical and physicochemical investigation

International audienc

Size Effect on the Acoustic Emission Behavior of Textile-Reinforced Cement Composites

Acoustic emission (AE) is applied for the structural health evaluation of materials. It commonly uses piezoelectric sensors to detect elastic waves coming from energy releases within the material. Concerning cementitious composites as well as polymers, AE parameters have proven their potential to not only detect the existence of a defect, its location and the fracture mode, but also the developing strain field even before visible damage evolves. However, the wave propagation distance, wave dispersion due to plate geometry, heterogeneity and reflections result in attenuation and distortion of the AE waveforms. These factors render the interpretation more complex, especially for large samples. In this study, the effect of wave propagation on plain glass textile-reinforced cement (TRC) plates is investigated. Then, curved plates with different widths are mechanically loaded for bending with concurrent AE monitoring. The aim is to evaluate to what extent the plate dimensions and propagation distance influence the original AE characteristics corresponding to a certain fracture mechanism

Multi-scale analysis of mechanical and thermal behaviour of mortars incorporating phase change materials

International audienc

Analytical modeling of textile reinforced concrete (TRC) sandwich panels: Consideration of nonlinear behavior and failure modes

International audienceThe emergence of new composite materials in the building industry allows textile reinforced concrete (TRC) to be used in many industrial applications such as structural strengthening and new lightweight structures. One of the most promising applications of TRC is as a potential alternative to steel reinforced concrete and fiber reinforced polymer (FRP) used in the skins of foamed sandwich panels. This study proposes an analytical method of designing TRC sandwich panels. Additionally, the method allows the load bearing capacity of TRC sandwich panels under bending solicitation to be calculated. The proposed model can promote TRC applications in the engineering and building industry. The proposed model considers the nonlinear behavior of TRC using the ACK approach for evaluating the axial and bending stiffness of TRC in the multicracking and textile transmission phases. Furthermore, the foam shear strains and foam hardening during bending solicitations are considered. The analytical approach was validated based on experimental data, and the validation process implemented was used to investigate the evolution of local strains in TRC skins to ensure the robustness of the developed model