Experimental Study of Flexural Behavior of Reinforced Concrete Beam Strengthened with Prestressed Textile-Reinforced Mortar

Abstract

In this study, nine specimens were experimentally tested to analyze the strengthening efficiency of textile-reinforced mortar (TRM) and the difference in flexural behavior between prestressed and non-prestressed TRM-strengthened reinforced concrete beam. The test results show that TRM strengthening improves the flexural strength of TRM-strengthened reinforced concrete beams with alkali-resistant-(AR-) glass textile as well as that with carbon textile. However, in the case of textile prestressing, the strengthening efficiency for flexural strength of the AR-glass textile was higher than that of the carbon textile. The flexural stiffness of AR-glass textiles increased when prestressing was introduced and the use of carbon textiles can be advantageous to reduce the decreasing ratio of flexural stiffness as the load increased. In the failure mode, textile prestressing prevents the damage of textiles effectively owing to the crack and induces the debonding of the TRM.experimentally study for the bond was conducted and effective anchorage length was derived for fibers/matrix interface [13], and the bond-slip relation was predicted considering the loss of bond between PBO-FRCM system and the concrete substrate [14]. The flexural behavior of the structure which was strengthened with TRM was also investigated [15][16][17][18][19][20][21][22][23][24]. Herbrand et al.[25] applied a carbon textile-reinforced mortar to real bridge. The experimental results indicated increasing the fatigue and ultimate strength of bridge. Koutas et al. [7] reported the state-of-the-art review on the strengthening of concrete structure with TRM including studies for flexural, shear, confinement, and seismic retrofitting.The designing and strengthening of TRM, however, is still difficult because such an uncertainty involves errors that may occur during weaving, material application, and the construction process. Theoretical studies were conducted to predict the flexural strength of TRM-strengthened RC beam [17,18,20,24]. An efficient factor is applied in the designing of strengthening TRM to consider the poor bond between textile and mortar [26,27]. ACI Committee 549 [28] proposes an effective tensile strain to limit the ultimate tensile strain of fabric-reinforced cementitious matrix (FRCM). Flexural strength was predicted according to ACI 549.4R and the results underestimated the experimental results [19,29].A method of manually stretching the textile or fixing both sides of the textile was adopted during the construction stage to reduce this uncertainty regarding TRM strengthening [15,27]. The method of stretching and fixing the textiles has the advantages of preventing the local bending of the textiles, which can occur when the textiles are placed on the mortar, and accurately maintaining the reinforced axis [27,30]. This method, however, has a disadvantage: the axial load applied to the textile is not constant. Consequently, some researchers analyzed the performance of a structure by introducing a prestress to the textile [31][32][33][34][...

Evaluation of Flexural Behavior of Textile-Reinforced Mortar-Strengthened RC Beam Considering Strengthening Limit

“…Studies have been conducted to prevent local textile bending and maintain accurate location at the designed reinforced axis by fixing both ends of the textile and manual stretching [27][28][29][30]; these studies had limitations because a constant tensile force was not introduced. In addition, to maximize the textile performance, studies on textile-reinforced concrete (TRC) and TRM using the pre-tension method have been conducted [31][32][33][34].…”

Reinforced Concrete Slabs Strengthened with Lap-Spliced Carbon TRC System

“…Early developments are well summarised in the literature [1][2][3][4], and recent developments and applications of the TRC system can be found in References. [5][6][7][8][9][10][11][12][13]. More recently, a research group in the Korea Institute of Civil Engineering and Building Technology (KICT) conducted a series of experimental investigations to utilise a TRC system for a new structural component and strengthening for deteriorated concrete elements.…”

Effect of TRC and F/TRC Strengthening on the Cracking Behaviour of RC Beams in Bending

“…The results confirmed such dependency upon the geometry, recording an increased number of cracks and reduced crack width for specimens strengthened with wider TRC elements. Park et al [26] instead focused on the number of cracks that appeared on the specimens, once again tested in a four-point-bending setup. They analysed both cracks on the whole length of the specimens and the ones that appeared in the pure bending zone.…”