Hygrothermal effects on high VF pultruded unidirectional carbon/epoxy composites: Moisture uptake

Comparative Study of the Durability Behaviors of Epoxy- and Polyurethane-Based CFRP Plates Subjected to the Combined Effects of Sustained Bending and Water/Seawater Immersion

“…In addition, CFRP composites may be also subjected to external loadings at the same time, such as sustained tensile stress in pre-stressed reinforcements [3,12] or bending strain [11]. Although many works [9][10][11]13] have been reported on the durability of CFRP composites, it is still a serious concern, especially under combined environment and stress conditions. In the present article, an epoxy resin, a common used resin matrix for CFRP composites, and a polyurethane (PU) resin system, a new emerging matrix for CFRP composites [14], were used for pultruded CFRP plates (CFRPs).…”

“…In addition, micro-cracks, formed during curing due to the large difference in thermal expansion coefficients of fiber and matrix, have been reported to increase water uptake [20]. During immersion, the micro-cracks may be converted into macro-cracks, and meanwhile some new micro-cracks may form due to swelling [9], resulting in increased water uptake [9,21]. External stresses, including tensile stress and compressive stress, play an important role on the water uptake of a FRP composite [11,[22][23][24].…”

“…During their service lives, they may suffer from certain harsh environments, such as moisture, water, and seawater even at elevated temperatures [7][8][9][10][11]. In addition, CFRP composites may be also subjected to external loadings at the same time, such as sustained tensile stress in pre-stressed reinforcements [3,12] or bending strain [11].…”

Influence of Hydrothermal Ageing on the Residual Stresses and Mechanical Behavior of Carbon/Epoxy Composite Laminates

“…Generally, the hydrothermal condition tends to degrade the performance of polymeric materials, which decreases the service life of CFRP composite materials [12]. For our work, the attention is given to the correction between the hydrothermal conditions and the residual stresses redistribution and then the materials mechanical properties.…”

Modeling of moisture diffusion in CFRP strengthened concrete based on thermal-moisture analogy

“…The weight gains of the adhesive samples increase proportionally to the square root of immersion time before reaching the saturation level, after one year and it follows the Fickian law of moisture uptake (Karbhari and Xian 2009). (13) where is the moisture uptake at time t, is the quasi-equilibrium moisture uptake, D is the diffusion coefficient, h is the thickness of the sample (2 mm for the samples in the experiment).…”