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www.anstar.eu 3 CONTENTS Page 1 PRODUCT DESCRIPTION...4 2 MATERIALS AND STRUCTURE...4 2.1 PRODUCT RANGE...4 2.2 MATERIALS...4 2.3 MANUFACTURING...4 2.4 MANUFACTURING TOLERANCES...4 2.5 QUALITY CONTROL AND MARKING...4 2.6 DIMENSIONS...5 2.6.1 ATP and AHP rebar bolts...5 2.6.2 ALP anchor bolts...6 2.6.3 AMP anchor bolts...7 3 CAPACITIES...8 3.1 BASIS OF DESIGN...8 3.2 BOLT CAPACITIES...8 3.3 COMBINED LOADINGS...8 4 THE USE OF ANCHOR BOLTS...9 4.1 RESTRICTIONS...9 4.2 DESIGN PRINCIPLES...9 4.3 PLACING OF BOLTS... 10 4.3.1 Minimum bolt edge distances for normal forces... 10 4.3.2 Minimum bolt centre to centre distances for normal forces... 10 4.3.3 Minimum bolt edge distances for shear force... 10 4.4 ADDITIONAL REINFORCEMENT... 11 4.4.1 Connection reinforcing principle... 11 4.4.2 Column to column joint... 11 4.4.3 Placing short stud head anchor bolts in slabs or low foundations... 11 4.4.4 Placing short stud head anchors in a foundation column... 12 4.4.5 Placing rebar bolts in a foundation column... 12 4.4.6 Placing AMP bolts in a column... 13 4.5 ADDITIONAL CLAUSES FOR T40 REBAR... 14 4.6 CORRECTION OF CAPACITY VALUES... 14 4.6.1 Change of concrete strength... 14 4.6.2 Small edge distance... 14 4.6.3 Small centre to centre distance... 14 4.6.4 Durability and concrete cover... 15 5 INSTALLATION... 15 5.1 FORMING A BOLT GROUP... 15 5.2 BOLT ASSEMBLY AND TOLERANCES... 16 5.3 BENDING AND WELDING OF BOLTS... 16 5.4 COLUMN INSTALLATION... 16 5.5 SAFETY PRECAUTIONS... 17 5.6 INSTALLATION CONTROL... 17 5.6.1 Instructions for bolt assembly... 17 5.6.2 Instructions for column installation... 17 Download free from www.anstar.fi ColJoint design program for bolt/column shoe connection
www.anstar.eu 4 1 PRODUCT DESCRIPTION The anchor bolt transfers forces acting in the bar direction to foundation or lower column by rebar bond or by stud head anchoring. Connection shear force is transferred to the concrete structure by the concrete edge pressure acting on the bolt shaft. 2 MATERIALS AND STRUCTURE 2.1 Product range The anchor bolt product range include following bolt types: ATP AHP ALP-L ALP-P AMP, -M Short rebar bolt with stud head anchor Rebar bolt with straight bonding rebar Short high strength anchor bolt with stud head anchors High strength anchor bolt with straight rebars Standard bolt for moment stiff connection between precast beam and column Beside the bolt the standard delivery contains 2 nuts and 2 round washers. For the AMP bolt lower nut and washer can be replaced with a round threaded steel plate. 2.2 Materials - Rebar T16-T32 SFS 1215 (EN 10080) A500HW (B500B), f y = 500 N/mm² Rebar T40 NS3576-3 B500NC - ALP thread High strength steel f y = 700 N/mm² Imacro M, Ovako f u = 800-1100 N/mm² - Nut ISO 898-1 Grade m8 - Washer EN 10025 S355J2+N 2.3 Manufacturing Method of manufacturing - Rebars and bolt materials are mechanically cut - Anchors are MAG welded with a robot or by hand to high strength steel bolt. Weld class C EN-ISO 5817. - Threads M16-M52 are rolled and M60 is cut. - Anchoring stud is hot forged and air cooled. Surface treatment options: 1) Black steel with lightly oiled thread is standard supply 2) Hot dip galvanizing according to EN ISO 10684 including also nuts and washers - ATP and AHP bolts are galvanized throughout - threaded part of ALP and AMP bolt is galvanized before welding black anchors 2.4 Manufacturing tolerances - Total bolt length ± 10 mm - Length of thread +5,-0 mm - Metric thread ISO 898-1 6g 2.5 Quality control and marking Anstar Oy has a quality control agreement with Inspecta Certification and Nordcert. The bolt production is certified according to standards EN 1090-1, EN 3834-2 and EN 17660-1. The shoes are manufactured with following markings: - control mark for Inspecta Certification and Nordcert - company name ANSTAR, CE-mark, product type and week of manufacture
www.anstar.eu 5 2.6 Dimensions 2.6.1 ATP and AHP rebar bolts ATP and AHP rebar bolts are used to join columns to foundations in connections transferring normal forces, shear forces and bending moments. ATP bolts are used in connections where short anchoring lengths are needed, such as in slabs and short foundation columns. AHP bolts can be used in foundations where there is enough space for straight rebar anchoring. K Ø T S ATP K L Ø D washer AHP L Fig. 1. ATP and AHP foundation bolts Table 1. Dimensions of ATP and AHP anchor bolts (order AHP with desired L) Typ L other lengths K As M Ø D S T weight colour mm in stock mm mm 2 mm mm mm mm mm kg ATP16 280 100 157 M16 T16 36 38 5 0,7 yellow ATP20 350 120 245 M20 T20 46 46 6 1,2 blue ATP24 430 140 353 M24 T25 58 55 6 2,2 l. gray ATP30 500 170 561 M30 T32 73 65 8 4,3 green ATP39 700 190 976 M39 T40 100 90 8 10,0 orange AHP16 800 100 157 M16 T16-38 5 1,5 yellow AHP20 1000 1500, 2000 120 245 M20 T20-46 6 2,7 blue AHP24 1200 1500, 2000, 2500 140 353 M24 T25-55 6 4,8 l. gray AHP30 1500 2000, 2500 170 561 M30 T32-65 8 10,2 green AHP39 2000 190 976 M39 T40-90 8 21,6 orange Also available as hot-dip galvanized. Table 2 and figure 2. Rebar lap length l 0,min (EC2) for bolt tensile force concrete strength C25/30 C32/40 bond condition η1 1,0 1,0 1,0 1,0 0,7 concrete cover α2 0,7 1,0 0,7 1,0 1,0 percentage α6 1,5 1,5 1,5 1,5 1,5 AHP16 482 689 574 821 1174 AHP20 602 860 720 1027 1467 AHP24 694 992 898 1284 1833 AHP30 857 1224 1149 1642 2367 AHP39 1303 1861 1561 2232 3187 l 0,min
www.anstar.eu 6 2.6.2 ALP anchor bolts ALP anchor bolts are used to join columns to foundations in connections transferring normal forces, shear forces and bending moments. ALP-L bolts are used in connections where short anchoring lengths are needed, such as in slabs and short foundation columns. ALP-P bolts can be used in foundations where there is enough space for straight rebar anchoring. K 50 Ø ALP22L,..., -52L ALP60L ALP-L K 50 L Ø D D ALP36P ALP39P ALP45P ALP52P ALP60P ALP22P ALP27P ALP-P L D D Fig. 3. ALP anchor bolts Table 3. Dimensions of ALP anchor bolts Typ L K As M Ø D S T weight colour mm mm mm 2 mm mm mm mm mm kg ALP22L 490 140 303 M22 3T16 80 55 6 2,6 l. blue ALP27L 620 170 459 M27 3T20 100 65 8 5,0 black ALP30L 650 170 561 M30 3T20 105 65 8 5,7 ALP36L 740 180 817 M36 3T25 130 80 8 10,0 red ALP39L 860 190 976 M39 3T25 135 90 8 12,6 braun ALP45L 970 210 1306 M45 3T32 150 100 10 22,5 purple ALP52L 1130 240 1758 M52 3T32 150 100 10 27,2 white ALP60L 1290 270 2362 M60 4T32 220 130 12 39,6 pink ALP22P 1070 140 303 M22 3T12 70 55 6 3,6 l. blue ALP27P 1150 170 459 M27 3T16 80 65 8 6,7 black ALP30P 1370 170 561 M30 3T16 85 65 8 8,0 ALP36P 1390 180 817 M36 4T16 105 80 8 11,8 red ALP39P 1490 190 976 M39 4T20 115 90 8 17,7 braun ALP45P 1710 210 1306 M45 4T20 135 100 10 23,6 purple ALP52P 1880 240 1758 M52 4T25 150 100 10 36,3 white ALP60P 2430 270 2362 M60 4T32 180 130 12 70,0 pink Also available as hot-dip galvanized (only threaded bar not anchors) L = Total length of bolt K = Length of thread K j = Area of threaded cross-section M = Metric thread size Ø = Amount and diameter of rebars D = Combined anchor space needed S = Washer diameter T = Washer thickness
www.anstar.eu 7 2.6.3 AMP anchor bolts AMP anchor bolts are used in moment stiff precast beam-to-column connections. Bolt dimensions have been designed for limited embedment space in concrete column. AMP bolts can also be used in connections where short anchoring lengths are needed, such as slabs and short foundation columns to transfer normal forces, shear forces and bending moments. AMP-M bolts are used to connect two precast beams facing opposite sides of the column. Product code is AMP-M-L (for example AMP52M-1480). AMP AMP-M K 50 U A Ø K 50 Column width Ø 50 K B L L Fig. 4. AMP anchor bolts Table 4. Dimensions of AMP anchor bolts Type L K As M A B Ø U S weight mm mm mm 2 mm mm mm mm mm mm kg AMP36 670 180 817 M36 160 80 T25 137 80 10,5 AMP39 680 190 976 M39 180 90 T32 140 90 13,8 AMP45 800 210 1306 M45 200 100 T32 165 100 20,7 AMP52 930 240 1758 M52 230 115 T32 190 100 38,3 AMP60 1490 270 2362 M60 270 130 T40 270 130 72,8 AMP36M-L - 180 817 M36 - - T25-80 - AMP39M-L - 190 976 M39 - - T32-90 - AMP45M-L - 210 1306 M45 - - T32-100 - AMP52M-L - 240 1758 M52 - - T32-100 - AMP60M-L - 270 2362 M60 - - T40-130 - L = Total length of bolt K = Length of thread K j = Area of threaded cross-section M = Metric thread size A = Length of anchor plate B = Width of anchor plate Ø = Diameter of rebars U = Anchor plate distance from thread S = Washer diameter
www.anstar.eu 8 3 CAPACITIES 3.1 Basis of design The anchor bolts have been designed according to: Tension: - EN 1993-1-1:2005 Design of Steel Structures, General rules - EN 1993-1-8:2005 Design of Steel Structures, Joints Tension resistance has been calculated with γ M2 = 1,25 (NA: FIN) - EN 1992-1-1:2004 Design of Concrete Structures, General rules Shear: - Elastically embedded bolt with edge distance 10Ø according to De Beer A slightly conservative capacity compared to CEN/TS 1992-4-2:2009 chapter 6.3, suitable for anchoring machinery (smaller displacements in serviceability limit state) 3.2 Bolt capacities The anchor bolts have been designed for tension and compression capacities calculated from the thread cross-section (EN 1993-1-8: 3.6). The bolt capacity is the same as the capacity for corresponding column shoe. Table 5. Design capacities for rebar bolts. Concrete C25/30. Bolt Normal force Shear force Corresponding good bond, α2 = 0,7 NRd [kn] VRd [kn] column shoe ATP16 AHP16 62.2 3.7 APK16 ATP20 AHP20 97.0 6.9 APK20 ATP24 AHP24 139.7 10.9 APK24 ATP30 AHP30 222.1 19.1 APK30 ATP39 AHP39 386.5 36.7 AK39 Table 6. Design capacities for high strength steel bolts. Concrete C25/30. Bolt Normal force Shear force Corresponding good bond, α2 = 0,7 NRd [kn] VRd [kn] column shoe ALP22L,-P 174.5 15.2 APK24 ALP27L,-P 264.4 25.2 APK30 ALP30L,-P 323.1 33.4 APK30 ALP36L,-P AMP36, -M 470.6 52.8 APK36 ALP39L,-P AMP39, -M 562.2 64.6 APK39 ALP45L,-P AMP45, -M 752.2 88.7 APK45 ALP52L,-P AMP52, -M 1012.6 123.9 APK52 ALP60L,-P AMP60, -M 1340.0 168.3 APK60 3.3 Combined loadings For combined tension and shear loads the following equation should be satisfied: (N Ed / N Rd) 1,5 + (V Ed / V Rd) 1,5 1,0 N Ed = Design tension load N Rd = Tension capacity V Ed = Design shear load V Rd = Shear capacity
www.anstar.eu 9 4 THE USE OF ANCHOR BOLTS 4.1 Restrictions Anchor bolt capacities have been determined for static loads. When designing dynamic actions larger load safety factors should be used and the connection system should be analysed for each case. Using capacity values require that the minimum centre to centre and edge distances as well as reinforcement instructions for transferring bolt loads to concrete are followed. Impact ductility properties of ALP and AMP bolt material enables normal usage to - 40 C. 4.2 Design principles In grouted joints bolts usually transfer only tension loads, while shear load is transferred by friction (EN 1993-1-8: 6.2.2). In ungrouted joints (installation) all loads will be carried by slender bolts. Shear loads are bending the threaded bolts and the compression side will determine the bolt size needed. Compression load acting on a bolt (symmetrical bolt group) N Edp = N Ed / n + M Ed / (0,5 * H * n) N Ed N Ed M Ed H n joint design compression load joint design bending load bolt c/c distance amount of joint bolts Bolt bending moment caused by shear load G M Ed M Q Ed M QEd = 0,5 * Q Ed * (G + M) / n Q Ed G M n joint design shear load grout thickness (mm) thread size (mm) amount of joint bolts Moment resistance H M Rd = 1,5 * f y * W x / 1,1 = 0,192 * f y * A s 1,5 N Edp A s thread cross-section f y = 500 MPa (rebars) f y = 640 MPa (high strength steel) Combined action N Edp / N Rd + M QEd / M Rd < 1,0 Fig. 5. Joint design before grouting
www.anstar.eu 10 4.3 Placing of bolts 4.3.1 Minimum bolt edge distances for normal forces AHP and ALP-P bolts The bolts require only an ordinary concrete cover thickness to the surface of the concrete structure according to EC2 chapter 4. ATP, ALP-L and AMP bolts The bolt minimum edge distances are determined for the stud head anchor. 4.3.2 Minimum bolt centre to centre distances for normal forces AHP and ALP-P bolts The bolts are placed according to requirements for lap spliced rebars. ATP, ALP-L and AMP bolts Bolt minimum centre to centre distances are determined for the stud head anchors. Table 7. Minimum edge and centre to centre distances for stud head anchors Bolt Minimum distance [mm] e1 e2 e3 e4 ATP16 38 76 ATP20 47 94 ATP24 56 112 ATP30 71 142 ATP39 93 186 A c1 ATP ALP-L A c1 ALP22L 63 126 ALP27L 78 156 ALP30L 88 176 ALP36L 104 208 ALP39L 113 226 ALP45L 131 262 ALP52L 152 304 ALP60L 160 320 e1 e2 e 1 AMP e 2 AMP36 75 150 115 230 AMP39 80 160 125 250 AMP45 90 180 150 300 AMP52 100 200 180 360 AMP60 110 220 215 430 A c1 e 1 e 2 A c1 e 3 e 4 4.3.3 Minimum bolt edge distances for shear force The bolt minimum edge distance for shear force is 10*Ø, if the shear force is transferred directly to concrete. If the edge distance is smaller the whole bolt shear force should be transferred using additional stirrups or U-bent rebars.
www.anstar.eu 11 4.4 Additional reinforcement 4.4.1 Connection reinforcing principle always require reinforcement of foundation and column so, that tension, compression and shear forces can be transferred to surrounding concrete. Following chapters describe some recommended reinforcing principles. 4.4.2 Column to column joint AHP bolts join precast concrete columns with steel shoes. The reinforcement should be designed according to following instructions, see figure 6. 1. Bolt tension and compression forces are transferred to the column by using a single main reinforcement bar corresponding to bolt or by using two smaller main reinforcement bars, the lap length of which must correspond to the bolt length. (see table 2) 2. All shear forces are transferred with the stirrup reinforcement A qt. 3. Transverse stirrups A st must be placed in both ends of the bolt according to EC2 section 8.7.4. These stirrups are given in table 9. AHP A qt + Ast Ast Fig. 6. Reinforcing principle for column top 4.4.3 Placing short stud head anchor bolts in slabs or low foundations Tension load Concrete cone failure is resisted by surface reinforcement or when needed with additional bent bars A rt. Compression load if H min 5*M if H min < 5*M no additional reinforcement is needed - U-links or stirrups A pt should transfer the whole action N d - use AMP bolts ATP ALP-L M A rt Apt H min Fig. 7. Placing ATP or ALP-L bolts into a slab
www.anstar.eu 12 4.4.4 Placing short stud head anchors in a foundation column Stud head bolts can also be placed into foundation columns. The reinforcement of the columns should be designed in the following manner: 1. Tension forces acting in the bolt should be transferred to the foundation by using main rebars bent as U-stirrups, which are anchored to the slab lower surface. The anchorage length of straight rebars is not usually long enough. 2. The bolt requires stirrup reinforcement A qt in the top of the foundation column to transfer shear forces, see figure 8. 3. Stirrups A vt for taking splitting forces should be placed above the stud heads according to figure 8. Ordinary stirrup reinforcement should be added to this stirrup area. Fig. 8. Placing ATP or ALP-L bolts in a foundation column ATP ALP-L A qt A vt Table 8. Splitting stirrups A vt for short bolts and additional stirrups A st for long bolts Bolt Splitting stirrups Bolt Additional stirrups Avt example Ast example ATP16 19 mm² 1T8 AHP16 70 mm² 2T8 ATP20 29 mm² 1T8 AHP20 110 mm² 3T6 ATP24 40 mm² 1T8 AHP24 160 mm² 4T8 ATP30 67 mm² 2T8 AHP30 250 mm² 5T8 ATP39 111 mm² 3T8 AHP39 400 mm² 5T10 ALP22L 51 mm² 1T8 ALP22P 60 mm² 2T8 ALP27L 76 mm² 2T8 ALP27P 101 mm² 3T8 ALP30L 88 mm² 2T8 ALP30P 101 mm² 3T8 ALP36L 135 mm² 3T8 ALP36P 101 mm² 3T8 ALP39L 161 mm² 4T8 ALP39P 157 mm² 4T8 ALP45L 216 mm² 6T8 ALP45P 157 mm² 4T8 ALP52L 290 mm² 6T8 ALP52P 245 mm² 5T8 ALP60L 386 mm² 5T10 ALP60P 402 mm² 6T10 4.4.5 Placing rebar bolts in a foundation column AHP and ALP-P anchor bolts can be placed in foundation columns where there is enough height. Tension forces acting in the bolts are transferred to the foundation with main rebars, which are anchored to lower surface of foundation. The reinforcement is placed in the following way, see figure 9. AHP: The anchorage length of the AHP bolts have been determined so, that straight rebars with same size placed in the column corners transfer the bolt loads. ALP-P: ALP-P bolts are anchored for full tension force with rebars of the same size as in the bolt. If rebars with larger diameters than the bolt anchor bars are used the lap length should be checked.
www.anstar.eu 13 To transfer bolt shear forces a stirrup reinforcement A qt should be placed in top of the foundation column. Addition stirrups A st should be placed in the lap ends, see table 8. ALP-P A qt + A st A st Fig. 9. Placing ALP-P bolts in a foundation column 4.4.6 Placing AMP bolts in a column AMP anchor bolts have been designed for moment stiff connection between precast beam and column. The rectangular anchor plate transfers compression loads to the concrete on front side of the column. The stud heads transfer tension loads to the opposite side. The longer side of the anchor plate is placed vertically in the column, this way the bolt can be placed close to the column edge. H Tension zone B Reinforcement for shear forces L A E ET D K Compression zone F F Fig. 10. Placing AMP bolts in a column Table 9. Minimum bolt distances in a rigid column-to-beam connection Bolt A F L D K E ET Hmin Bmin mm mm mm mm mm mm mm mm mm AET36 100 90 710 540 170 50 40 580 380 AMP36 100 90 670 500 180 50 80 580 380 AMP39 110 100 680 500 180 60 70 580 480 AMP45 110 110 800 605 195 60 70 680 480 AMP52 110 130 930 700 230 60 70 780 580 AMP60 110 130 1490 1220 270 70 100 1380 580 A = Bolt distance from bracket F = Minimum edge distance to column side L = Total length D = Embedment length into column K = Length of visible thread E = Distance from surface of beam assembly plates ET = Minimum concrete cover for stud head H = Minimum rectangular column height B = Minimum rectangular column width
www.anstar.eu 14 4.5 Additional clauses for T40 rebar The bolt AHP39 based on rebar T40 concrete bond can be used in following conditions (EC2 chapter 8.8): 1. Use bundled rebars 2T32 or 3T25 in lap joints or consider a lower stress level. 2. Stirrups are always used as confining reinforcement 3. Additional reinforcement and crack control must be considered in each case. 4.6 Correction of capacity values 4.6.1 Change of concrete strength The capacity values of the anchor bolts can be corrected in relation to concrete grade in the following way: Normal force capacity For lower concrete grade C20/25 the capacities should be corrected by multiplying with 0,83. Instead of reducing capacities for AHP bolts with Lmin you can choose a longer stock size bolt, e.g. AHP24-2000. Shear force capacity Bolt shear force capacities can be modified for both lower and higher concrete grades than C25/30 with correction factor n: n = f ck / 25 where f ck is the characteristic compressive cylinder strength for concrete used 4.6.2 Small edge distance If ATP, ALP-L and AMP bolts are placed closer to the structure s edge than required in section 4.2, the bolt capacity values should be reduced in the following manner. Normal force With minimum edge distance the bolt normal force capacity is taken as 100. When bolt centre is at the edge of the structure this value is 0. Any values in between can be linearly interpolated. The bolt may not be placed closer to edge than concrete cover required for stud head. Shear force The use of full bolt shear capacity requires a minimum edge distance 10*Ø. If a smaller edge distance is used, all shear forces should be transferred to concrete by stirrups. With adequate reinforcement there is no need to reduce the bolt shear capacity. 4.6.3 Small centre to centre distance If ATP, ALP-L and AMP bolts are placed closer to each other than the required minimum centre to centre distance, the bolt capacity values should be reduced in the following manner: Normal force With minimum distance from each other the combined tension capacity is taken as 100. When the bolt centres overlap this value is 50. Any values in between can be linearly interpolated. Shear force There is no need for correction. All shear forces are anchored with stirrup reinforcement.
www.anstar.eu 15 4.6.4 Durability and concrete cover The durability of the concrete joint with anchor bolt and steel shoe is designed according to EC2 chapter 4. The same exposure class is chosen for joint as for column and foundation structure if there is no special need to use a higher class. Check structural fire design when needed. Concrete cover of anchors The nominal concrete cover of anchor bars and anchor plates are determined according to exposure class related to environmental conditions. Concrete cover of threads The concrete cover and protection of threaded part including nuts and washers is determined according to exposure class: Exposure class X0 - In dry and warm conditions visible steel parts are painted if they can be maintained later. - Without maintainability the steel parts are covered with a required concrete cover. Exposure classes XC1 and XC3 - All bolt parts are covered with a required concrete layer and the leakage of water into the connection is prevented by structural solutions. - In cold and humid conditions bolts are hot-dip galvanized. Exposure classes XC2, XD4, XD, XS and XF - The use of anchor bolts in these environmental conditions should always be checked. The steel parts must in all circumstances be covered with a non cracking concrete layer. The leakage of water into the connection has to be prevented by structural solutions. 5 INSTALLATION 5.1 Forming a bolt group The anchor bolts are concreted into a bolt group by using an AAK assembly frame. With the frame it is easy to secure the right bolt positions, it also protects the threads during concrete casting. A rectangular assembly frame with four bolts can be ordered by using product code AAK-M- H*B, where M is thread size and H*B are bolt centre to centre distances. H B Fig 11. AAK assembly frame
www.anstar.eu 16 5.2 Bolt assembly and tolerances When using APK column shoes the anchor bolts should be assembled in the foundation concrete according to height levels given in figure 12 and table 10. Also in other applications the bolt height levels may not differ more than the allowable tolerance, so that full bolt capacities can be used. Table 10. Bolt height levels with APK steel shoes Bolt corresponding A G torque size column shoe mm mm Nm AHP16 APK16 105 50 100 AHP20 APK20 115 50 200 AHP24 APK24 130 50 350 AHP30 APK30 150 50 650 AHP39 AK39 180 60 1000 ALP22 APK24 130 50 200 ALP27 APK30 150 50 350 ALP30 APK33 170 50 650 ALP36 APK36 170 60 800 ALP39 APK39 180 60 1000 ALP45 APK45 195 70 1500 ALP52 APK52 230 80 2500 ALP60 APK60 260 80 3500 A G Fig 12. Bolt height level A = Bolt height level from concrete G = Grouting thickness under column The bolts are cast into concrete with following tolerances: Height tolerance ± 20 mm Maximum allowable bolt inclination L/100 Bolt hole clearance in column shoe M16-M30 ± 5 mm M36-M60 ± 7 mm When assembly tolerances are exceeded please ask further instructions from project s structural designer. 5.3 Bending and welding of bolts When needed, straight rebars can be bended at site (not the threaded part). When bending rebars the requirements concerning bending radius and working temperatures should be followed. Lap lengths to main reinforcement should be checked for the bent bolt. It is recommended that no load carrying fixings are welded to the rebars without consulting the structural designer. 5.4 Column installation Column installation is started by levelling the upper surface of lower washers to correspond to the planned bottom level of the precast column. The column is lifted to its place and the upper nuts are tightened. The column is levelled into an upright position by adjusting the bolt nuts. The nut housings have been designed for DIN 7444 slugging wrenches. Tightening torque values are given in table 11. The values correspond to 40 % of rebar and 20 % of high strength steel bar yield strength. The bolts are locked with double nut or by breaking the thread above the nut. The given torque is not enough for cyclic compressiontension loaded bolts.
www.anstar.eu 17 The grouting of the column shoe and the nut housings is done according to grout manufacturer s instructions. The grout concrete should be non-shrinking and correspond to the column concrete strength. 5.5 Safety precautions The anchor bolt threads are to be protected during and after concrete casting. The bolts may not be loaded before the concrete has achieved its design strength if the plans do not specify anything else. When installing columns the working order and the assembly supporting plan should be followed. Grouting of the connection should be done according to the installation schedule and the grouting concrete should reach the planned strength before upper structures can be assembled onto the column. 5.6 Installation control 5.6.1 Instructions for bolt assembly Before casting - ensure that bolt and frame according to plan (type, dimensions) are used and that steel parts are not damaged - ensure that the bolt group position in the formwork corresponds to given tolerances - ensure that bolt height level corresponds to given tolerances - ensure that the additional reinforcement has been installed - see that the bolt group is tightly fixed to formwork - see that the bolt threads are protected until column installation. After casting - check that bolt positions are in accordance with given tolerances - write a measurement report. 5.6.2 Instructions for column installation The column erection is done according to designer s installation plan. The assembly controller should check the following: - installation order - supports and bracings during installation - tightening of nuts - joint grouting schedule and grouting instructions