Strengthening of Stone Masonry Structures using Textile bonded with Sarooj Mortar

المشروع: Other project

تفاصيل المشروع

Description

In recent years, the importance of structural interventions in the area of architectural heritage (monuments, historic buildings, etc.) for repair and strengthening has increased considerably. Oman is a place that hosts a great heritage of historical structures such as forts, castles, towers, aflaj (irrigation channels) etc. Most of these historical structures were constructed few centuries ago and as such were of the type of unreinforced masonry (UM) structures. The proposed research focuses on the feasibility and effectiveness of using textile-reinforced sarooj mortar (TRSM) in the repair and strengthening of unreinforced masonry elements. Production of TRSM is based on the use of textile fabrics which are impregnated with cement paste or mortar. The experimental part of proposed research will be through the testing of different sarooj mortars for optimized tensile and bond strength; testing of masonry beams to upgrade their out of plane (flexural) and in plane (shear) capacity of masonry walls.

Layman's description

In recent years, the importance of structural interventions in the area of architectural heritage (monuments, historic buildings, etc.) for repair and strengthening has increased considerably. Oman is a place that hosts a great heritage of historical structures such as forts, castles, towers, aflaj (irrigation channels) etc. Most of these historical structures were constructed few centuries ago and as such were of the type of unreinforced masonry (UM) structures. The proposed research focuses on the feasibility and effectiveness of using textile-reinforced sarooj mortar (TRSM) in the repair and strengthening of unreinforced masonry elements. Production of TRSM is based on the use of textile fabrics which are impregnated with cement paste or mortar. The experimental part of proposed research will be through the testing of different sarooj mortars for optimized tensile and bond strength; testing of masonry beams to upgrade their out of plane (flexural) and in plane (shear) capacity of masonry walls.

Key findings

Studies in the use of textiles in upgrading of masonry or concrete structures have been very limited. Using of textile reinforced concrete for strengthening in bending and shear was reported by Bruckner et al. [4]. Using test results it was demonstrated how thin layers of concrete with textile reinforcement can be used for strengthening of reinforced concrete (RC) members. The enhancement of bending capacity was illustrated with flexural strengthened RC-slabs. It was also established that the shear capacity may be increased through strengthening of RC-beams, and that properties of serviceability were improved, in particular the reduction of deflections and crack widths.The application of textile reinforced mortar (TRM) as a means of increasing the shear resistance of reinforced concrete members was investigated by Triantafillou et al. [5]. Based on the experimental response of reinforced concrete members strengthened in shear it was concluded that textile-mortar jacketing provides substantial gain in shear resistance; this gain is higher as the number of layers increases and, depending on the number of layers, is sufficient to transform shear-type failure to flexural failure. TRM jackets were provided in this study either by conventional wrapping of fabrics or by helically applied strips. Both systems resulted in excellent results in terms of increasing the shear resistance. However, compared with their resin-impregnated counterparts, mortar-impregnated textiles may result in reduced effectiveness.The application of textile-reinforced mortars (TRMs) as a means of increasing the axial capacity of concrete through confinement was investigated by Triantafillou et al. [6]. Based on the response of confined cylinders and short rectangular columns, it was concluded that textile-mortar jacketing provides a substantial gain in compressive strength and deformability; this gain is higher as the number of confining layers increases and depends on the tensile strength of the mortar. Compared with their resin-impregnated counterparts, mortar-impregnated textiles may result in reduced effectiveness. This reduction was more pronounced in cylindrical specimens but rather insignificant in rectangular ones. Favorable confinement characteristics on rectangular columns were also obtained by using helically applied unbonded strips with end. From the results obtained in this study, it is believed that TRM jacketing is an extremely promising solution for the confinement of reinforced concrete. Porta et al. [7] investigated in-plane behavior of tuff masonry strengthened with composite materials. Particularly, a cement based matrix-coated alkali resistant glass grid system (CMG) was used to strengthen tuff masonry walls; different CMG layouts were selected, and overall performances were compared with those of as-built ones. Tuff masonry panels were subjected to diagonal compression loading order to measure their in-plane deformation and strength properties. The performance observed in the laboratory confirmed that the CMG system satisfies basic design requirements such as compatibility with the support, high bond properties, and reversibility of the intervention. Significant improvements of strength and ductility of panels were achieved installing different layouts of the CMG grid.The results of an experimental study to evaluate the bond between fiber reinforced polymer (FRP) ? glass and carbon FRP ? and steel reinforced polymer (SRP) with historic masonry was presented by Capozucca [8]. The FRP were in the form of sheets, while the SRP were in the form of grid system. Pull?push shear tests on FRP/SRP-to-historic clay brick bonded joints specimens were carried out. Experimental tests confirmed that historic brick bonded joints lose their capacity by brittle delamination failure when composite FRP sheets were used, while a more ductile failure was observed in bricks strengthened with SRP grid system. This also indicates that using textile, which basically a grid system of FRP, has great potential in strengthening of historical structures.References 1. Triantafillou TC, Fardis MN. Strengthening of historic masonry structures with composite materials. Materials and Structures. 1997;30(202):486-96. 2. Hago AW, Al-Rawas A, Al-Harthi AS. Determination of optimum volume proportions for sarooj (pozzolan) lime mixes. Environmental and Engineering Geoscience. 2000;6(2):171-6. 3. Hansen, Brett. "Technology: Textile replaces steel in reinforced concrete." Civil Engineering, v 76, n 4, April, 2006, p 38 4. Bruckner, A; Otrlepp, R. and Curbach, M. ?Textile reinforced concrete for strengthening in bending and shear.? Materials and Structures, v 39, n 292, October, 2006, p 741-748. 5. Triantafillou, T. C.; Papanicolaou, C. G. "Shear strengthening of reinforced concrete members with textile reinforced mortar (TRM) jackets." Materials and Structures, v 39, n 285, January/February, 2006, p 93-103 6. Triantafillou, T. C.; Papanicolaou, C. G.; Zissimopoulos, P.; Laourdekis, T. "Concrete confinement with textile-reinforced mortar jackets." ACI Structural Journal, v 103, n 1, January/February, 2006, p 28-37 7. Prota A, Marcari G, Fabbrocino G, Manfredi G, Aldea C. Experimental in-plane behavior of tuff masonry strengthened with cementitious matrix-grid composites. J Composite Constr. 2006;10(3):223-33. 8. Capozucca R. Experimental FRP/SRP-historic masonry delamination. Composite Structures. 2010;92(4):891-903.
عنوان قصيرIn recent years, the importance of structural interventions in the area of architectural heritage (monuments, historic buildings, etc.) for repair and strengthening has increased considerably. Such interventions often follow special guidelines. Very sign
اختصارTTotP
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بصمة

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