Effect of adhesive replacement with cement mortar on NSM strengthened RC Beam

Abstract

This paper presents the experimental behavior of reinforcement concrete beams strengthened with near surface mounted (NSM) steel bar. Several researchers have used NSM fiber reinforced polymer (FPR) bar or strip for strengthening reinforced concrete beams. Though FRP has a number advantages like high strength, light weight and corrosion resistance it doesn't show any ductile behavior, still highly expensive and not easily available in market. On the other hand, steel bar is less expensive, readily available in the market and shows good ductility. In order to get rapid and economic strengthening solution, strengthening with near surface mounted steel bar may become a potential alternative to retrofit reinforced concrete members. Therefore, the main purpose of this paper to investigate the experimental behavior of reinforced concrete beam strengthened with near surface mounted steel bar. Seven full-size beams (one control beams and six strengthened beams) were tested. Steel bars were used for strengthening. The failure load, mode of failure, deflection, and strain behavior are discussed. The study reveals that the near surface mounted technique with steel bars and cement mortar is the most economical strengthening solution to increase the flexural performance of RC beams.Keyword: Strengthening, Near surface mounting, Steel bar, Reinforced concrete, Low cost strengthening materials, Cement mortar. ResúmenEn este trabajo se presenta el comportamiento experimental con mortero de cemento en Viga NSM de Hormigon Reforzado fortalecida. Varios investigadores han utilizado barra o tiras de NSM (montaje cercano a la superficie) de FRP (polímero reforzado con fibra) para el fortalecimiento de vigas de hormigón armado. Aunque FRP tiene un número de ventajas como alta resistencia, ligereza y resistencia a la corrosión, no muestra ningún comportamiento dúctil, siendo muy caros y no están fácilmente disponibles en el mercado. Por otro lado, la barra de acero es menos costosa, fácilmente disponible en el mercado y muestra una buena ductilidad. Con el fin de obtener una solución rápida y económica, el fortalecimiento con barra de acero NSM puede llegar a ser una alternativa potencial para adaptar los miembros de hormigón armado. Por lo tanto, el objetivo principal de este trabajo para investigar el comportamiento experimental de las vigas de hormigón armado reforzado con barras de acero NSM. Se ensayaron siete vigas de tamaño completo (una viga de control y seis vigas reforzadas). Barras de acero se utilizaron para el fortalecimiento. La carga de rotura, modo de fallo, deformación, y el comportamiento de tensión se discuten. El estudio revela que la técnica NSM con barras de acero y mortero de cemento es la solución de fortalecimiento más económica para aumentar el rendimiento de flexión de vigas RC.

Experimental Study on the Effectiveness of Inorganic Bonding Materials for Near-Surface Mounting Shear Strengthening of Prestressed Concrete Beams

“…Organic resins such as epoxy and vinyl esters are widely used as bonding materials in FRP strengthening of concrete members, however, inorganic resins possess numerous advantages over the organic resins; including: (a) better resistance against high temperatures, (b) improved UV resistance, (c) handling and use is simpler as the inorganic resins are water-based, (d) they emit no toxic smells during strengthening, and (e) comparable chemical bonding with concrete. When properly designed, it is possible to replace organic resins with inorganic ones for most strengthening applications [19][20][21][22][23][24][25]. Rahman et al [19] studied the efficiency of cement mortar and epoxy resin as a bonding material for NSM strengthening.…”

“…When properly designed, it is possible to replace organic resins with inorganic ones for most strengthening applications [19][20][21][22][23][24][25]. Rahman et al [19] studied the efficiency of cement mortar and epoxy resin as a bonding material for NSM strengthening. They found that the replacement of 50% epoxy with mortar resulted in better performance without altering the flexure dominant failure.…”

Experimental Analysis of Traditional and NFRP Concrete for Frame Members

“…The experimental performance of concrete beams reinforced with a steel bar to discuss failure in the load, the regime of failure, deflection, and strain performance. The study reveals that proposed techniques most cost-effective reinforcement to increase the bending efficiency of RC beams [2].The loading has been implemented through a motion management regime. The four samples are utilized for experimentation.…”

Numerical simulation of shear-strengthening of reinforced concrete beams by CFRP under cyclic loading

“…Fiber reinforced polymer (FRP) composites have been increasingly used in concrete structures in recent years because of their corrosion resistance, low weight, high tensile strength and large strain (Rahman, Jumat, Hosen, & Islam, 2016). Shear strengthening of beams can be implemented quickly by external carbon fibre-reinforced polymer (CFRP).…”