S&P ARMO-System Design Guidelines

Transcription

1 S&P ARMO-System Design Guidelines November 2010

2 Table of Contents 1. Introduction 3 2. Comparison of FRP (Fibre Reinforced Polymer) / 5 ARMO strengthening systems 3. Technical data of the S&P ARMO-mesh 6 4. Anchoring & overlapping of S&P ARMO-mesh 8 5. S&P anchor element aluminium Flexural enhancement using the S&P ARMO-System S&P ARMO-flexion Software for flexural enhancement S&P ARMO-axial Software for axial enhancement Shotcrete for tunnel and general civil constructions Structural strengthening of existing tunnel linings Seismic strengthening of masonry using S&P ARMO-mesh Technical data for S&P ARMO-crete S&P ARMO-crete d S&P ARMO-crete w S&P ARMO-System - Product overview Test reports / References (P) 31 Appendix: Texts of specification 2 / 37

3 1. Introduction Several different methods are available for the strengthening of reinforced concrete structures: - subsequent addition of columns or beams - subsequent installation of steel beams - addition of steel rebars with shotcrete - external bonding of steel plates or FRP (Fibre Reinforced Polymer) etc. S&P is a global leader in developing, manufacturing and distributing FRP systems. S&P's FRP systems can be affixed to existing structural elements as sheets, woven or prefabricated laminates using certified adhesives. Various local norms and design guidelines exist regarding external bonding with FRP (Fibre Reinforced Polymer) General building authority approval Z /70 (Germany) SIA 166 Swiss code for FRP Recommendations for FRP systems: ACI 440 (USA) TR55 (UK) CUR 91 (NL) CNR-DT 200/2004 (IT) Building authority approvals for S&P FRP systems have been granted in other countries (France, Korea, etc.) as well. FRP systems are state of the art worldwide and have established themselves as a costeffective and durable method for subsequent strengthening during the past 15 years. While reinforced concrete (RC) design is bound by the defined maximum allowable steel stress, FRP reinforcements are subject to a limit strain. The maximum allowable strain depends on the type of loading (flexural, shear or axial strengthening) and the FRP system. The limit strains are defined differently in the various FRP codes or national technical approvals depending on the safety concept. 3 / 37

4 The following limit strains are currently used at ultimate state design: Stiffness increase using carbon FRP systems Flexural enhancement FRP plates (surface bonded) ~ % Carbon Sheets (surface bonded) ~ % FRP plates (near surface mounted)) ~ % FRP plates (externally prestressed at 6 ) ~ % Enhancement of axial compression column Carbon FRP (C-FRP) wrapping ~ 0.4 % Shear strengthening Carbon FRP (C-FRP) wrapping ~ % Ductility Improvement Glass FRP (G-FRP) wrapping 3 4 % Aramid FRP (A-FRP) wrapping 2 3 % S&P has developed a new strengthening system called "S&P ARMO-System" and applied for a patent in 2009/2010. S&P proposes a design method for the S&P ARMO strengthening system based on currently valid FRP design concepts. For the S&P ARMO system, carbon mesh is rolled out on site, laid out and grouted using a reactive mineral spray mortar. As the S&P ARMO-mesh is treated with amorphous silica and the mortar includes a reactive component, calcium silica hydrate grows from the mortar into the carbon filaments of the S&P reinforcing (Figure 1 and Figure 2). This results in a shearresistant interlocking and anchoring of the S&P ARMO-mesh with the mortar. Figure 1: S&P ARMO- mesh with traditional spray mortar Figure 2: S&P ARMO-mesh in ARMO-crete 4 / 37

5 S&P offers various spray mortars with reactive components for different applications: S&P ARMO-crete d ready-mix spray mortar for dry method (various grains, admixtures and cements) S&P ARMO-crete w spray mortar for wet method S&P ARMO-mur plaster (for interior and exterior applications) The S&P ARMO-mesh is additionally filled with ceramic-powder. The ceramic works as a oxygen barrier at high temperature. The C-fiberbundles are therefore protected against oxidation in case of fire. 2. Comparison of FRP (Fibre Reinforced Polymer) / ARMO strengthening systems FRP systems are applied to concrete, wood, etc. using shear-resistant epoxy resin adhesives. The tensile modulus of elasticity of epoxy adhesives is roughly four times less than the tensile elastic modulus of concrete. Thus the thickness of the adhesive layer of C-FRP plates is limited to 3 5 mm. For thicker layers the load transfer from the C-FRP strip into the concrete structure cannot be ensured. When using FRP systems the unevenness of the underlying surfaces must be re-profiled before the adhesive is applied. Usually re-profiling mortars on an epoxy resin basis are used. With the ARMO- System however, the S&P ARMO-spray mortar matrix is optimally attuned to concrete as a material. The tensile elastic modulus of mineral spray mortar is comparable to that of concrete. Mineral spray mortar has a high ph-value and is permeable to water vapour. Re-profiling and application of the carbon reinforcing is performed in a single operation. Re-profiling is unnecessary when using the S&P ARMO-System. Reprofiling occurs during the application of the spray mortar layer in a single operation. The evenness of the ARMO-mesh during the application is very important. The application shall be carried out in accordance to the specification of the supplier. The ARMO-mesh is fixed or laid into the mortar after the first layer of ARMO-crete is applied. Different options are available to fix the ARMO-mesh: The ARMO-mesh is laid between two layers of ARMO-crete: - If the wet spray mortar S&P ARMO-crete w or the plaster ARMO-mur is used, the S&P ARMO-mesh can be applied without any fixing system. The grid is worked into the wet mortar. - If the dry spray mortar S&P ARMO-crete d is used the following fixing methods are possible: - S&P twisting plate (the S&P mesh is worked into the fresh spray mortar) - S&P clamps (the S&P mesh is fixed in the lightly cured spray mortar - S&P dowels (the S&P mesh is fixed in the fully cured spray mortar) 5 / 37

6 Table 1 shows a comparison between FRP systems and the S&P ARMO-System. Moisture of structural surface Surface conditioning Re-profiling works FRP System ARMO-System Carbon within Epoxy Matrix Carbon within Mineral Matrix < 4% residual moisture Pre-wet structural surface slight roughening (grinding or sand blasting) great effort for levelling / re-profiling Deep roughening (sand blasting or water jetting) No additional effort Application Easy / convenient Great installation effort (rendering, covering) Building physics Corrosion protection of interior rebars Fire safety Additional clarification necessary FRP acts as a local vapour barrier Elaborate additional works necessary Corrosion protection of rebars Impregnation or thin coating between FRP Residual safety in case of fire must be verified and if necessary fire safety measures must be applied. Table 1: Comparison of FRP and ARMO Strengthening Systems No additional clarification necessary ARMO-System is permeable to vapour ph-value of 12 for ARMO- System No additional works are necessary. ARMO-System offers alkali projection for interior rebars. The matrix (ARMO-crete) is heat resistant. F60 (60 minutes resistance) at ca. 1 cm cover of the ARMO-mesh. 3. Technical data of the S&P ARMO-mesh S&P offers different mesh versions. Mesh for structural strengthening in the longitudinal direction (carbon fibres in direction of unrolling only) S&P ARMO-mesh L500 S&P ARMO-mesh L200 Mesh for structural strengthening in both directions S&P ARMO-mesh 200/200 Mesh for structural strengthening in the cross direction (crack cover) S&P ARMO-mesh C200 6 / 37

7 Technical data ARMO-mesh L500 ARMO-mesh L200 (main direction length) ARMO-mesh C200 (main direction cross) ARMO-mesh 200/200 (both directions) Elastic modulus (theoretical) [kn/mm 2 ] Reduction factor on elastic modulus due to application Elastic modulus (reduced) for design [kn/mm 2 ] Ultimate tensile strength C-fibre (theor.) [N/mm 2 ] Weight of C-fibre in main direction [g/m 2 ] Density C-fibre [g/cm 3 ] Elongation at rupture (therotical) [%] Theoretical thickness of C-fibre for design (fibre weigh t density) [mm] Theoretical cross section C-fibre for design [mm 2 /m] Ultimate tensile force at 1.75 % (theoretical) [kn/ m] Tensile force for desing (S&P recommendation) (2x80 for S&P ARMO-mesh 200/200) Flexural (~ 800 N/mm 2 ) (Limit strain at ultimate state 0.5 %) Axial (~ 640 N/mm 2 ) (Limit strain at ultimate state 0.4 %) [kn/m] [kn/m] ARMO-mesh L500 ARMO-mesh L200 ARMO-mesh 200/200 Width / length of roll: 1.95 m / 50 m ARMO-mesh C200 Width / length of roll: m / 50 m Table 2: Technical Data for the S&P ARMO-mesh 7 / 37

8 Mesh for shrinking reinforcement (made of AR-Glass) S&P ARMO-Glass fibre reinforcement AR Technical Data for both directions S&P ARMO-Glass Fibre Reinforcement AR Mesh size [mm] 35 Failure strain [%] 4.5 Ultimate tensile force [kn/ m] 25 Width / length of roll: [m] 2.20 / 100 Table 3: Technical Data for S&P ARMO-Glass fibre reinforcement AR 4. Anchoring & overlapping of S&P ARMO-mesh Transferring loads from the steel rebars into the concrete is achieved through the use of ribbed reinforcing bars which enhance the bond between the two materials. For ribbed reinforcing the following simple rule applies Lap length for reinforcing bars = 60 x Ø reinforcing bar The tensile strength of carbon fibres is seven to eight times higher than that of reinforcing steel. Also, carbon-fibre bundles do not possess any surface texture. S&P ARMO-mesh layers are also not spot welded as are reinforcing steel meshes. In order to improve the anchoring of the S&P ARMO-mesh in spray mortar, a special coating of the grillage surface was developed by S&P. The coating consists of an aqueous polymer that is tempered with amorphous silicate. A reactive component is included in the spray mortar S&P ARMO-crete respectively S&P ARMO-mur. The necessary anchoring length (overlapping) of S&P ARMO-mesh L500 was verified in pull-out tests on double concrete specimens (P 11). Figures 3, 4 and 5 show the test arrangement. 8 / 37

9 Figure 3 Figure 4 Figure 5 Figure 3: Double concrete specimen before testing Figure 4: Application of spray mortar and S&P ARMO-mesh L500 Figure 5: Test Specimen after pull-out test A total of 12 specimens were tested while varying the following parameters: Anchorage length 10 / 30 cm Traditional spray mortar (no reactive component) S&P ARMO-crete w spray mortar (with reactive component) Application of one or two layers of S&P ARMO-mesh L500 Graphic 1 shows the results. Graphic 1: Results of the pull-out tests 9 / 37

10 The influence of the reactive component is clearly visible. If S&P ARMO-mesh L500 is used under flexural tension in a design situation with 5 of limit strain, a force of 93.6 kn/m must be anchored (refer to Table 2). Table 4 lists the recommended anchor lengths with a safety factor of 30 %. S&P ARMO-mesh L500 Flexural tension (5 ) Table 4: Reinforcement lengths for S&P ARMO-mesh w/o reactive component (cm) w/ reactive component (cm) Test Test + 30 % Test Test + 30 % ~ 15 ~ 20 ~ 28 ~ The reactive component of the spray mortar reduces the anchorage length by roughly 30 %. 5. S&P anchor element aluminium When strengthening flexural elements with S&P ARMO-mesh there may be cases where anchoring the reinforcement behind the point of zero moment is not possible (Graphic 2). Graphic 2 Graphic 3 In these cases, the remaining force in the S&P ARMO-mesh is anchored behind the point of zero moment using the S&P anchorage element made of aluminium (Graphic 3). The shear studs of the anchorage element are not designed for the full tensile force of the S&P ARMO-mesh L500 in this case. The load transfer into the structural surface occurs primarily through the front of the anchorage element and thus through the connection joint between spray mortar and structural surface. The shear studs of the S&P Anchor element aluminium are design only for the necessary contact pressure in order to fasten the anchorage element within the mortar. 10 / 37

11 The effectiveness of the S&P Anchor element aluminium was proven using plate bending tests (P 20 / P 10). Graphic 4 shows the test arrangement. A 60 cm span was chosen for the plate bending test. The anchorage length on both sides is thus only 50% of 60 = 30 cm. Graphic 4: Plate bending test arrangement Three test specimens were tested using S&P ARMO-mesh L500 without end anchorage (P 20). Three test specimens were tested using S&P ARMO-mesh L500 with end anchorage (P 10). For these tests, spray mortar S&P ARMO-crete d (4 mm grain) was used. Graphic 5 and Graphic 6: Load-deflection diagram for test specimens shows the test results (average values of the three test specimens) of the three test specimens without anchoring and the three with anchoring. Graphic 5: Load-deflection diagram for test specimens with and without anchoring 11 / 37

12 Graphic 6: Work-deflection diagram for test specimens with and without anchoring Results: Work capacity without S&P end anchorage Alu 626 J Work capacity with S&P end anchorage Alu 1139 J (+ 82%) In the plate bending test (Figure 6) without anchoring of the S&P ARMO-mesh the Carbon bundles were pulled into the test specimen. The S&P Alu end anchorage was able to prevent this. Failure there occurred because of the spray mortar delaminating from the concrete surface. The end anchorage also increased the work capacity (J) by 82% (Figure 7). Figure 6: VHS test arrangement Figure 7: VHS test specimen at failure 12 / 37

13 6. Flexural enhancement using the S&P ARMO-System The structural design for the S&P ARMO-System can be performed following currently valid FRP design guidelines, codes or technical approvals. The technical University of Fribourg/CH carried out researches with the S&P ARMO-System. The research program was corresponding to an existing research program done with the S&P FRP Systems. Tests at the FH Fribourg (CH) a) Research with S&P FRP Systems A reference RC-slab was compared with RC-slabs reinforced with different FRP Systems (P 21). Dimensions / Slab / Rebars Slab: Rebars: Thickness 22 cm Total length 6.3 m longitudinal 6 Ø 12 (S 500) Width 85 cm Span length 6.0 m transversal Ø 8 S = 150 (S 500) Figure 8: Test arrangement at the FH Fribourg (CH) Graphic 7: Test arrangement at the FH Fribourg (CH) 13 / 37

14 FRP strengthening: A reference RC-slab LAO was compared with RC-slabs reinforced with the following different FRP Systems (P 21) LA2: 2 x S&P CFK plates 150/2000 (50 x 1.2) LA4: 2 x S&P CFK plates 150/2000 (80 x 1.2) LA5: S&P C-Sheet 240 (200 g/m 2 ) The results are presented in graphic 8 / 9. The technical data of the FRP are in accordance to the S&P technical data sheets. The S&P CFK plates have a C-fibre content of 70% (table 5). C-fibre content / 0.85m width of slab LA2: 2 x S&P CFK plates 150/2000 (50 x 1.2) 84 mm 2 LA4: 2 x S&P CFK plates 150/2000 (80 x 1.2) mm 2 LA5: S&P C-Sheet 240 (200 g/m 2 ) 99.5 mm 2 Table 5: C-fibre content of FRP Reinforcing factor LA2: + 54% LA4: + 74% LA5: + 81% Graphic 8: Diagram Force / Deflection Strain ultimate state in FRP (delamination of FRP) LA2: 6 LA4: 5 LA5: 6 Graphic 9: Diagram Force / Elongation FRP centre of slab 14 / 37

15 b) Research with S&P ARMO-System A reference RC-slab was compared with RC-slabs reinforced with the S&P ARMO-mesh L500 (P 15). Figure 9: Application of S&P ARMO-System The dimensions and the internal rebars of the RC-slab were accordingly to the test serie reinforced with the S&P FRP System. ARMO strengthening: A reference RC-slab was compared with RC-slabs reinforced with 1-layer of S&P ARMOmesh L500 respectively 2-layers. The technical data of the S&P ARMO-mesh L500 is in accordance to table 2. 1-layer ARMO-mesh (laid in 1.5 cm ARMO-crete) 2-layers ARMO-mesh (laid in 2 cm ARMO-crete) Table 6: C-fibre content / ARMO strengthening C-fibre content / 0.85m width of slab 99.5 mm mm 2 The results are presented in graphic 10 / 11 / / 37

16 Graphic 10 presents the diagram force / deflection of the reference slab and the slab retrofitted with the ARMO-mesh: Reinforcing factor 1-layer ARMO-mesh: + 36% 2-layers ARMO-mesh: + 70% Graphic 10: Force / deflection The elongation on the concrete surface (tension side) was measured. The relevant strain/stress in the S&P ARMO-mesh was calculated. In graphic 11 / 12 the results (elongation and strain in concrete compressive zone) are presented: Strain/Stress at failure in ARMO-mesh (calculated) approx. 8 / 720 N/mm 2 Graphic 11: Force / Elongation across 2.4 m length at middle of slab on the tension side Early failure in compressive zone of concrete. The ARMO-mesh was not completely activated. Graphic 12: Force / strain in concrete compressive zone 16 / 37

17 In table 7 the C-fibre content and the relevant reinforcing factor of the FRP and ARMO strengthening is compared: Serie C-fibre content Reinforcing factor LA2: 2 x S&P CFK plates 150/2000 (50 x 1.2) 84 mm % LA4: 2 x S&P CFK plates 150/2000 (80 x 1.2) LA5: S&P C-Sheet 240 (200 g/m 2 ) mm % 99.5 mm % 1-layer ARMO-mesh (laid in 1.5 cm ARMO-crete) 2-layers ARMO-mesh (laid in 2 cm ARMO-crete) Table 7: C-fibre content / Reinforcing factor FRP resp. ARMO System 99.5 mm % 190 mm % S&P recommends the following design concept for the S&P ARMO-System based on the research of technical University Fribourg/CH. Reduction factor of 1.5 on the elastic modulus for design due to the application. Limit strain at ultimate state in accordance to the following table: Reduction factor on the elastic modulus: 1.5 Elastic modulus for design (reduced): 160 kn/mm 2 Limit strain at ultimate state: Flexural enhancement 0.5% (tension 800 N/mm 2 ) Axial enhancement 0.4% (tension 640 N/mm 2 ) Shear enhancement 0.2% (tension 320 N/mm 2 ) The photos in Figure 10, 11, 12 show different possibilities of applying the S&P ARMO- System for the flexural enhancement of tunnels, civil constructions and bridges. Figure 10, 11, 12: Applications of the S&P ARMO-mesh for buildings, tunnels and bridges 17 / 37

18 7. S&P ARMO-flexion Software for flexural enhancement S&P ARMO-flexion (Figure 13) serves as design software for the strengthening of reinforced and prestressed concrete structural elements subject to uniaxial bending combined with axial force using the S&P ARMO-System. The program can be used both for the design of strengthening measures as well as to produce verifiable check calculations as part of a structural analysis. The program yields the necessary carbon fibre cross-section for ARMO-mesh L500, L200 or 200/200. In addition, the software performs anchorage checks as required by the S&P ARMO-System design guidelines. Tested standardized spray mortars S&P ARMO-crete d and S&P ARMO-crete w are used. The design follows the technical approvals as well as recommendations and codes for FRP systems. Figure 13: ARMO-flexion design software 8. S&P ARMO-axial Software for Axial Strengthening S&P ARMO-axial (Figure 14) is design software for the strengthening of axially compressed reinforced concrete columns using the S&P ARMO-System. Strengthening is based on the fact that wrapping the column prevents cross/radial expansion of the column. This creates a triaxial stress state in the concrete which increases the concrete compressive strength. S&P ARMO-axial can be used both for the design of strengthening measures as well as to produce verifiable check calculations as part of a structural analysis. For a pre-defined load the program will calculate the necessary number of wrapping layers of S&P ARMOmesh L500 or L200. Tested standardized spray mortars S&P ARMO-crete d and S&P ARMO-crete w are used. The design follows the technical approvals as well as recommendations and codes for FRP systems. 18 / 37

19 Figure 14: ARMO-axial design software 9. Shotcrete for tunnel and general civil construction Shotcrete is used in tunnel construction in order to secure excavations or for the actual tunnel lining. When securing excavations the shotcrete is primarily reinforced using steel fibres. Laying reinforcement mats in an unsecured excavation is too problematic due to safety concerns. For shotcrete tunnel linings, steel reinforcement mats are generally used. Especially in conventional tunnel excavation the unevenness of the tunnel surface is very pronounced. Steel mats can thus not be placed such as to tightly follow the tunnel vault. Additional shotcrete is necessary to even out the surface. When using S&P ARMO-mesh the shotcrete layer is thinner. The flexible carbon mesh and thus the shotcrete lining follow the unevenness of the tunnel profile. When the bearing surfaces are uneven the steel reinforcing is relatively distant from that bearing surface over large areas. During the shotcreting process the steel mats begin to vibrate resulting in increased recoil and the creation of a spray voids behind the reinforcement (Figure 15). Figure 15: Spray voids behind steel reinforcing Figure 16: Fixing of S&P mesh using clamps 19 / 37

20 S&P is offering different fixing systems for the S&P ARMO-mesh (clamps, dowels or twisting plate). Alternatively the ARMO-mesh can be applied wet-in-wet with the shotcrete. Advantages of the S&P ARMO-System: The shotcrete layer's thickness can be reduced (less need to even out the profile / less cover for the carbon fibre reinforcement). The carbon fibre is inert and thus not subject to corrosion. Aggressive mountain water or alternating current cannot harm the reinforcement in the long run. The ph-value of the shotcrete is irrelevant to the corrosion protection of the reinforcement. Carbonation of the concrete, e.g. in vehicular tunnels, does not impact the functioning of the carbon reinforcement. Chlorides which may penetrate into the shotcrete around the portals also do not cause damage to the carbon mesh. A later widening of the tunnel (pilot drift) is also possible without problems. The carbon mesh does not adversely affect subsequent milling operations. In general civil construction different application are possible. Figures 17 / 18 show a shotcrete wall in an excavation. The shotcrete made with steel fibre is locally strengthened. Over the anchor, strips of the S&P ARMO-mesh L500 are applied in two directions. In addition the S&P ARMO-mesh 200/200 is applied on top of the anchor against punching shear. The ARMO-mesh is applied wet in wet into the first shotcrete layer. Figure 17 / 18: local reinforcement with the ARMO-mesh in the section of the anchor 20 / 37

21 Comparison of shotcrete lining with steel reinforcement / S&P ARMO-mesh The criterion for comparison of reinforced shotcrete linings is the work capacity as defined in different codes. A 10 cm thick shotcrete layer with a steel mesh 150/150 Ø 8mm placed in the middle usually has a work capacity of around 800 Joules. This work capacity can also be achieved with roughly kg/m 3 of steel fibres. At the test drift in Hagerbach, Switzerland, (P 10 / P 19) the work capacity of a 10 cm thick shotcrete lining with S&P ARMO-mesh was tested. For the test, an 8 cm thick traditional shotcrete layer was applied. Afterwards, the S&P ARMO-mesh was placed into a 2 cm thick layer of S&P ARMO-crete d. Two mesh variants were tested: - S&P ARMO-mesh L500 (unidirectional carbon fibre) - S&P ARMO-mesh 200/200 (bidirectional carbon fibre) Figure 19, 20, 21 show the application. Table 8 lists the results and compares them to steel reinforcement 150/150 Ø 8 mm. Figure 19, 20, 21: Application of the test specimen to determine work capacity Test Specimen 10 cm standard shotcrete with steel reinforcement in middle (Mesh Ø 8mm 150/150) 8 cm existing shotcrete with single layer of ARMO-mesh L500 in 2cm ARMO-crete d (anchored) 8 cm existing shotcrete with single layer of ARMO-mesh 200/200 in 2cm ARMO-crete d Work Capacity 800 Joule 1,139 Joule 824 Joule Table 8: Hagerbach Test Drift Results (P 10 / P 19) 21 / 37

22 10. Structural strengthening of existing tunnel linings The S&P ARMO-System is especially suited for the rehabilitation and structural strengthening of damaged existing linings of pressure tunnels or in road and railroad construction. The prevailing advantage of the S&P ARMO-System consists in the ability to reduce the shotcrete layer by a few centimetres such that after rehabilitation there is a larger sectional area available for flow or clearance. If a steel mesh is used in the repairs then the shotcrete layer is roughly 8 cm thick. This minimum thickness for the layer is necessary in order to even out the profile, apply the steel mesh and create a minimum cover for the steel layer of 3 cm. A 3 cm thick concrete cover is necessary to guarantee fire resistance (Resistance 60 minutes) and protect the included reinforcement against corrosion (ph-value of 12 within the shotcrete). The S&P ARMO-mesh, however, only needs a concrete cover of 1 cm to guarantee fire resistance. The heat resistance of the carbon fibre is three to four times higher than for steel rebars. A minimum cover for corrosion protection is actually not necessary. For this reason, the shotcrete layer will be nearly half as thick (Table 19). Thickness of Shotcrete Layer in cm Traditional with steel mesh S&P ARMO-System Evening out of the profile Shotcrete in area of rebars 1-2 Not relevant Concrete cover Total Table 9: Reduction of the shotcrete layer For the rehabilitation e.g. of tunnels in hydro power plants, oven-dried shotcrete mixtures (available in sacks or in bulk) are often used for logistical reasons. S&P offers prefabricated shotcrete mixtures for use as dry-mix sprays. The spray mortar S&P ARMO-crete d (dry) is produced with various admixtures and cement types. Delivery of the material in bulk material or sacks is possible from several production facilities. 22 / 37

23 The following provides a comparison the costs for an 8 cm thick traditional shotcrete layer with steel mesh and a 4 cm thick shotcrete lining using the S&P ARMO-System. 8 cm Shotcrete with traditional steel mesh Shotcrete material costs (in bags), 8 cm at ca /cm 56.--/m 2 Application costs 17.--/m 2 Delivery/placement of the steel mesh (in difficult conditions) 25.--/m 2 Total 98.--/m 2 4 cm S&P ARMO-crete with S&P ARMO-mesh L500 or 200/200 Material costs for S&P ARMO-crete, 4 cm at ca /cm (+30%) 34.--/m 2 Application costs (+ 25 %, due to lower amount of spray works) 20.--/m 2 Delivery/placement of the S&P ARMO-mesh 22.--/m 2 Total 76.--/m 2 (-20%) The S&P ARMO-System offers additional advantages for the owner: The ARMO-mesh replaces the steel reinforcement; the shotcrete layer is thinner. No spray shadow/void behind the S&P ARMO-mesh. Less recoil as there is no vibration as would occur with steel reinforcement. 3 x higher heat resistance and only 1 cm of concrete cover necessary. No corrosion of the carbon reinforcement and minimum required concrete cover. Greater clearance or flow section of the tunnel or drift. 23 / 37

24 11. Seismic strengthening of masonry using S&P ARMO-mesh Strengthening Using FRP Systems In the years 2007/2008, 15 masonry walls were cyclically loaded at the FH Fribourg (CH). The masonry was reinforced using different S&P FRP systems (strips, sheets, etc). The FRP reinforcement was always anchored in the adjacent concrete areas. Figure 22/ Graphic 13 shows the test arrangement. Figure 22: Test rig at the FH Fribourg Graphic 13: Test arrangement at the FH Fribourg Two different series were run. Series A Vertical load of 1.0 N/mm 2 (P 16) Series B Vertical load of 0.5 N/mm 2 (P 17) A very high load was chosen for Series A. As the vertical load is reduced in a seismic event (vertical lift-off of the element) the load was reduced in Series B. Table 10 lists the results obtained for Series B. The masonry was reinforced with S&P C-Sheet 240 of 200 g/m 2 (bands of 300 mm width) in different arrangements on one or both sides (Figure 23, 24, 25). Horizontal load % Horizontal deflection % B1: Reference B2: 2 vertical bands B3: 2 vertical bands + 2 bands at 45º B4: 4 vertical bands + 45º B5: 2 vertical bands + 60º Table 10: Result summary for S&P C-Sheet 240, 200 g/m 2 in different arrangements 24 / 37

25 Figure 23, 24, 25: Different arrangements of the S&P C-Sheet 240 Deductions: The results of the cyclic load tests show that FRP-reinforced walls can resist significantly higher horizontal loads than unreinforced walls. The reinforcements on one or both sides showed comparable results. The increased resistance of the reinforced masonry walls however can only be utilized comprehensively if the bricks and joints can resist the increased loads. The deflections of the reinforced masonry walls were generally increased by up to 10%. It should therefore be possible to reinforce load-bearing masonry walls of existing structures especially in zones with a lower risk of seismic activity and for such structures that fall into building categories I or II in accordance to different design code. Reinforcement with S&P ARMO-mesh In order to investigate the behaviour of the S&P ARMO-mesh another test series C (P 18) was performed at the FH Fribourg/CH. These identical tests were executed this time using the S&P ARMO-mesh L500 (200 g/m 2 ) instead of the FRP system S&P C- Sheet 240 (200 g/m 2 ). An identical width for the reinforcement bands was chosen. The S&P ARMO-System was anchored in the adjoining concrete element and applied on one side only. Figures 26 / 27 show the application of the des S&P ARMO-System. Figure 26 / 27: Application of the S&P ARMO-System 25 / 37

26 S&P ARMO-mur, a plaster with reactive component, was used as spray mortar. The plaster can be applied by hand or mechanically. Two products are offered by S&P. One product is for interior applications while the other for the exterior. The vertical load in Series C corresponds to the loads in Series B. Table 11 lists the results for Series C, where the S&P ARMO-System was used as reinforcing. The comparative values for Series B (S&P C-Sheet 240) are given in Table 11 as well. Horizontal load Horizontal deflection % % C1: Reference C2: 2 vertical bands C3: 2 vertical bands + 2 bands at 45º C4: 4 vertical bands + 45º C5: 2 vertical bands + 60º (B2) (B3) (B4) (B2) (B3) (B4) (B5) 167 (B5) Table 11: Result overview for S&P ARMO-System in different arrangements / Comparison The effect of strengthening of the S&P ARMO-System is comparable with the results of the FRP enhancement. For all tests for the "seismic reinforcing of masonry" using S&P products the reinforcement bands were always anchored in the adjacent structural member. In practice this is possible using the S&P Anchor element aluminium as shown in Graphic 14. Figure 28 / 29 / 30 are showing a application on a job site where the masonry is enhanced against earthquake. The S&P ARMO-mesh is anchored in the concrete slab and the concrete floor. 26 / 37

27 Graphic 14: Connection details of adjacent member In this case, the tensile force is fully anchored through the dowels connecting with the adjacent concrete member. Figures 28 / 29 / 30: seismic enhancement of a masonry by the use of the S&P ARMO-mesh The retrofitting of an existing masonry wall by using the S&P ARMO-mesh laid in the S&P ARMO-mur (mortar) is an innovative and economic technique. The efficiency of the system will be verified with additional researches by independent laboratories. 27 / 37

28 12. Technical Data for S&P ARMO-crete 12.1 S&P ARMO-crete d High-quality shotcrete (gunite) for structural strengthening of reinforced concrete structural members using dry-spray method with reactive component. Product variants Grain size: 4 mm S&P ARMO-crete d4 8 mm S&P ARMO-crete d8 Admixtures: Microsilica S&P ARMO-crete d4m Quick binder S&P ARMO-crete d4s S&P ARMO-crete d8m S&P ARMO-crete d8s Cement: Portland cement is used in the standard product. If desired, sulphate-resistant cement can be used. Technical Data Type Modified dry-mix shotcrete (gunite) Delivery Powder (bags of 40 kg / bulk) Colour Gray ph-value 12 Density ~ kg/dm3 max. grain size 4 mm or 8 mm Working temperature 5-30 ºC Compressive strength 4mm grain: Compr. strength at 7/28 days: ca. 35/45 N/mm² w/ quick binder (S) ca. 30/35 N/mm² w/ microsilica (M) ca. 40/50 N/mm² S and M ca. 35/45 N/mm² 8 mm grain: Compr. strength at 7/28 days: ca. 45/50 N/mm² w/ quick binder (S) ca. 35/40 N/mm² w/ microsilica (M) ca. 50/55 N/mm² S and M ca. 40/45 N/mm² Tensile strength after 28 days: > 6 N/mm² Adhesive tensile strength on concrete after 28 days: > 1.5 N/mm² (EN 1542) Adhesive tensile strength ARMO-System (shotcrete/armo-mesh/bearing surface) after 28 days: > 1.0 N/mm² (design basis for load transfer to bearing surface) Modulus of elasticity ca N/mm² Frost resistance high (all variants) Frost/de-icing salt resistance high (M variant) Chloride ion penetration after 6 months < 0.6 % of the cement mass (M variant) Temperature change compatibility R4 (M variant) Capillary water absorption < 0.50 kg*m -2 h -0.5 (R4) (M variant) Possible layer thicknesses 4 mm grain: cm (S variant cm) 8 mm grain: 3 8 cm (S variant 3 12 m) Water dosage ca. 10 % of weight Remarks Standard values are highly dependent on bearing surface and processing (25-30 kg/cm/m 2 of layer thickness). Concrete group acc. to DIN SpC35/45 Table 12: Technical data for S&P ARMO-crete d 28 / 37

29 12.2 S&P ARMO-crete w High-quality spray mortar for structural strengthening of reinforced concrete structural members using wet-spray method with reactive component. Technical Data Type modified wet-spray mortar Delivery powder (bags of 25 kg) Colour Grey ph-value 12 Density ~2.05 kg/dm3 max. grain size 2 mm Water addition 17 % of weight Working temperature 5-30 ºC Open time (20 ºC) 30 min Mechanical strength (EN 12190) Compressive strength after 24h: > 18 N/mm² Compressive strength after 7 days: > 40 N/mm² Compressive strength after 28 days: > 60 N/mm² Flex. tensile strength after 28 days: > 8 N/mm² Adhesive tensile strength on concrete (EN 1542) after 28 days: > 2 N/mm² Adhesive tensile strength ARMO-System (shotcrete/armo-mesh/bearing surface) after 28 days: > 1.0 N/mm² (design basis for load transfer to bearing surface) Adhesive tensile strength on concrete after freezethaw-cycle > 2 N/mm² (EN ) Adhesive tensile strength on concrete after > 2 N/mm² temperature shock (EN ) Adhesive tensile strength on concrete after dry > 2 N/mm² thermal cycles (EN ) Capillary absorption (EN 13057) <0.2 kg m -2 h -0,5 Possible layer thicknesses 5-50 mm CE Number 1370-CPD-0217 Table 13: Technical data for S&P ARMO-crete w 29 / 37

30 13. S&P ARMO-System - Product Overview S&P ARMO-mesh (structural reinforcement) Longitudinal unidirectional reinforcement Type Ultimate longitudinal tensile force (kn/m) Reel length (m) Reel width (m) L L Transverse unidirectional reinforcement Type Ultimate cross tensile force (kn/m) Reel length (m) Reel width (m) C Bidirectional Reinforcement Type Ultimate longitudinal and cross tensile force Reel length (m) Reel width (m) (kn/m) 200/ S&P ARMO-Glass fibre reinforcement (non-structural) Bidirectional non-structural reinforcement out of AR glass (alkali resistant) Type Ultimate longitudinal and cross tensile force Reel length (m) Reel width (m) (kn/m) Glass fibre reinforcement S&P ARMO-crete S&P ARMO-crete d S&P ARMO-crete w Dry-mix shotcrete Delivery in bulk or in bags Wet-spray mortar Delivery in bags S&P ARMO-mur Plaster for interior or exterior application S&P ARMO Alu end anchorage The end anchorages are produced object-specific. Please enquire about delivery options. S&P Fixing Systems for the ARMO-mesh S&P twisting plate S&P clamps S&P dowels 30 / 37

31 14. Test Reports / References (P) P 10 Prüfbericht Nr A, S&P ARMO-mesh L500 (in eine Richtung, endverankert) Plattenbiegeversuch, , VSH, CH P 11 Endverankerungen von S&P ARMO-mesh L500, Okt.-Dez. 2009, S&P Clever Reinforcement Company AG, CH P 15 P 16 P 17 P 18 Renforcement de dalles en beton au moyen de treillis en fibres de carbone (Projet de recherche AGP 14'105) Projet de recherche AGP 21'159, Série expérimentale MR-A, Essais de cisaillement de murs en maçonnerie renforces, janvier 2010, FH Fribourg, CH Projet de recherche AGP 21'159, Série expérimentale MR-B, Essais de cisaillement de murs en maçonnerie renforces, mars 2010, FH Fribourg, CH Projet de recherche AGP 21'159, Série expérimentale MR-C, Essais de cisaillement de murs en maçonnerie renforces, janvier 2010, FH Fribourg, CH (Version provisoire) P 19 Prüfbericht Nr S&P ARMO-mesh 200/200 Plattenbiegeversuch, , VSH, CH P 20 Prüfbericht Nr A, S&P ARMO-mesh L500 (in eine Richtung) Plattenbiegeversuch, , VSH, CH P 21 Flèches, déformations / 37

32 Texts of specification: R Structural retrofitting of concrete members with carbon-fibre reinforced wet-spray mortar.100 Regulations.110 Valid codes and regulations are binding for the execution of all required works..120 Quality Management.121 The quality management system of the system supplier Must ensure that all quality requirements are satisfied. The system supplier of the spray mortar and the carbon fibre reinforcement must supply all relevant structural design calculations (required carbon cross-sectional area, anchorage check) for the reinforced structural section..122 The contractor must grant the owner or his representative access to all relevant documentation. R Site Installation.001 Haulage and supply of the machinery and devices necessary for the execution of the works. One site assignment must be included. CHF Work interruptions Reimbursement for work interruptions due to construction-site related issues. Scope: Number of interruptions each CHF Scaffolding works Assembly and supply of scaffolding during construction. CHF 0.00 R Preliminary works.001 Removal of plaster in the area of the reinforced spray mortar/shotcrete mechanically or by hand. m 2 CHF Sand-blasting or hydro-mechanical preparation of the bearing surface. Method chosen:... m 2 CHF Moistening of the bearing surface until Capillary saturation of the entire area of Spray mortar application. m 2 CHF / 37

33 R Structural retrofitting using carbon-fibre reinforced wet-spray mortar.100 S&P ARMO-mesh applied in single layer Delivery and grouting of the S&P ARMO-mesh, wet in wet using S&P ARMO-crete w as wet-spray mortar layer of 1.5 cm thickness. Rough spray surface. Typical usage of S&P ARMO-crete w: kg/m² per cm of layer thickness System supplier: S&P Clever Reinforcement Company AG Seewernstrasse 127, CH-6423 Seewen Tel , Fax S&P ARMO-mesh L500 Ultimate tensile resistance of 500 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh L200 Ultimate tensile resistance of 200 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh 200/200 Ultimate tensile resistance of 200 kn/m in both directions m 2 CHF S&P ARMO-mesh C200 Ultimate tensile resistance of 200 kn/m in cross direction m 2 CHF S&P ARMO-mesh applied in double layer Delivery and grouting of the S&P ARMO-mesh, wet in wet using S&P ARMO-crete w as wet-spray mortar layer of 2.0 cm thickness Rough spray surface. Typical usage of S&P ARMO-crete w: kg/m² per cm of layer thickness System supplier: S&P Clever Reinforcement Company AG Seewernstrasse 127, CH-6423 Seewen Tel , Fax S&P ARMO-mesh L500 Ultimate tensile resistance of 500 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh L200 Ultimate tensile resistance of 200 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh 200/200 Ultimate tensile resistance of 200 kn/m in both directions m 2 CHF S&P ARMO-mesh C200 Ultimate tensile resistance of 200 kn/m in cross direction m 2 CHF / 37

34 R Glass-fibre reinforced wet-spray mortar (reinforcement against shrinking).100 S&P ARMO-Glass Fibre Reinforcement applied in single layer Delivery and grouting of the S&P ARMOglass fibre reinforcement in ARMO-crete w using Wet-spray mortar of 1.5 cm layer thickness. Rough spray surface. m 2 CHF 0.00 Typical usage of S&P ARMO-crete w: kg/m² per cm of layer thickness System supplier: S&P Clever Reinforcement Company AG Seewernstrasse 127, CH-6423 Seewen Tel , Fax R Additional Charges.100 Treatment of surfaces and edges.101 Scraped surface, spray roughness m 2 CHF Screeded surface m 2 CHF Bevelling of edges m 1 CHF 0.00 R Curing.001 Keep moist and secure the entire spray mortar surface against weather, draft or sunshine for 7 days. m 2 CHF 0.00 TOTAL Spray Mortar Reinforcement (excl. 7.6 % VAT) CHF / 37

35 R Structural retrofitting of tunnel linings with carbon-fibre reinforced dry-mix shotcrete.100 Regulations.110 Valid codes and regulations are binding for the execution of all required works..120 Quality Management.121 The quality management system of the system supplier Must ensure that all quality requirements are satisfied. The system supplier of the spray mortar and the carbon fibre reinforcement must supply all relevant structural design calculations (required carbon cross-sectional area, anchorage check) for the reinforced structural section. The quality management system of the system supplier Must ensure that all quality requirements are satisfied..122 The contractor must grant the owner or his representative access to all relevant documentation. R Site Installation.001 Haulage and supply of the machinery and devices necessary for the execution of the works. One site assignment must be included. CHF Work interruptions Reimbursement for work interruptions due to construction-site related issues. Scope: Number of interruptions each CHF Scaffolding works Assembly and supply of scaffolding during construction. gl CHF 0.00 R Preliminary works.001 Cleaning of the existing tunnel vault using high-pressure water jets. m 2 CHF 0.00 R Structural retrofitting using carbon-fibre reinforced dry-mix shotcrete.100 S&P ARMO-mesh applied in single layer Delivery and grouting of the S&P ARMO-mesh, in S&P ARMO-crete d using dry-mix shotcrete layer of 2-3 cm thickness. Rough spray surface. Typical usage of S&P ARMO-crete d: kg/m² per cm of layer thickness 35 / 37

36 System supplier: S&P Clever Reinforcement Company AG Dammstrasse 2, 6440 Brunnen Tel , Fax S&P ARMO-mesh L500 Ultimate tensile resistance of 500 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh L200 Ultimate tensile resistance of 200 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh 200/200 Ultimate tensile resistance of 200 kn/m in both directions m 2 CHF S&P ARMO-mesh C200 Ultimate tensile resistance of 200 kn/m in cross direction m 2 CHF S&P ARMO-mesh applied in double layer Delivery and grouting of the S&P ARMO-mesh, in S&P ARMO-crete d using dry-mix shotcrete layer of 3-4 cm thickness. Rough spray surface. Typical usage of S&P ARMO-crete d: kg/m² per cm of layer thickness System supplier: S&P Clever Reinforcement Company AG Dammstrasse 2, 6440 Brunnen Tel , Fax S&P ARMO-mesh L500 Ultimate tensile resistance of 500 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh L200 Ultimate tensile resistance of 200 kn/m in longitudinal direction m 2 CHF S&P ARMO-mesh 200/200 Ultimate tensile resistance of 200 kn/m in both directions m 2 CHF S&P ARMO-mesh C200 Ultimate tensile resistance of 200 kn/m in cross direction m 2 CHF 0.00 R Glass-fibre reinforced dry-mix shotcrete (reinforcement against shrinking).100 S&P ARMO-Glass fibre reinforcement applied in single layer Delivery and grouting of the S&P ARMOglass fibre reinforcement in ARMO-crete d using dry-mix shotcrete layer of 2-3 cm thickness. 36 / 37

37 Rough spray surface. m 2 CHF 0.00 Typical usage of S&P ARMO-crete d: kg/m² per cm of layer thickness System supplier: S&P Clever Reinforcement Company AG Dammstrasse 2, 6440 Brunnen Tel , Fax R Additional Charges.100 Treatment of surfaces and edges.101 Scraped surface, spray roughness m2 CHF Screeded surface m2 CHF Bevelling of edges m1 CHF 0.00 R Admixtures for S&P ARMO-crete d.100 Addition of admixtures or special supplements for shotcrete S&P ARMO-crete d Scope: Dosage per ton of shotcrete.101 Admixing of quick binder to CHF Admixing of microsilica to CHF Use of sulphate-resistant cement to CHF 0.00 R Curing.001 Keep moist and secure the entire spray mortar surface against weather, draft or sunshine for 7 days. m2 CHF 0.00 TOTAL Shotcrete Reinforcement (excl. 7.6 % VAT) CHF / 37