Modelling the loss in strength of AR-glass fibres in textile-reinforced concrete

Experimental investigations on the durability of fibre–matrix interfaces in textile-reinforced concrete

“…The following degradation processes are generally reported in the literature: -Corrosion of the fibre material itself due to attack of OH À ions in the pore solution [8][9][10][11][12]. -Static fatigue (delayed failure) of the glass fibre under sustained load in the highly alkaline environment [13][14][15][16][29][30][31][32][33]. -Densification of the matrix adjacent to the filaments and enhancement of the fibre-matrix bond with continued hydration and precipitation of hydration products in the interface between filaments and matrix as well as in empty spaces between the filaments of multi-filament yarn (bundle filling) [4,[17][18][19][20][21][22][23]36].…”

“…The delayed failure of glass fibres is supposed to dominate the other mechanisms according to [29][30][31][32][33]. Purnell [29,30] proposed a static fatigue model to explain the losses in strength of artificially aged GRC, which had been described empirically by Litherland's model [28] before.…”

“…Orlowsky et al [31][32][33] enhanced the static fatigue model by introducing two reaction rate coefficients. These coefficients describe on the one hand the kinetic part of the defect growth (which is due to reactions between stressed glass and water or OH À ) and on the other hand the diffusion-controlled part of damaging process (transport of water or OH À to the defect tip, increasingly hindered by the deposit of recondensed silanol groups) [31].…”

“…Already at small displacements of the filaments the Portlandite crystals as well as the brittle shells around the filaments tend to shatter, wedge themselves unfavourably, and exert notching at the filaments and lateral punctual pressure. Furthermore, chemomechanical notching at the fibre surface [11] as well as growth of surface defects (invisible in ESEM) may occur [29][30][31][32][33]. All these effects can lead, separately or in combination with one another, to failure of the filaments even at relatively low loads.…”

Flexural Behavior of Textile-Reinforced Concrete

“…Various methods for the reinforcement of composites, such as the casting of concrete into the mold of the fabric and using a mixture of steel and non-metallic fibers are discussed in [13,14]. In studies [15][16][17][18], various models, such as the computer model of the composite structure of concrete, models describing the behavior of the structure under the influence of prolonged stress and corrosion were analysed. Existing methods to strengthen reinforced concrete superstructure, including the strengthening of composite materials based on carbon fibers in the polymer matrix are investigated in [19].…”