The influence of material and geometric parameters on the design of steel mechanical anchors to concrete under tension loading

Transcription

1 ITERTIOL JOURL OF MECHICS Volue 1, 018 The inluence o aterial and geoetric paraeter on the deign o teel echanical anchor to concrete under tenion loading Michal Štrba, Marcela Karazínová and Veronika Václavíková btract Thi paper deal with oe proble in cae o the eective and eicient deign o pot-intalled teel echanical expanion anchor to concrete which are jected to the tenion loading uing either tatic or cyclic loading orce. lo the inluence o oe elected paraeter and characteritic in cae o the loadcarrying capacity deterination and o the actual behaviour o thee atening eber i dicued. ll the preented inoration and reult are otly baed on the previou theoretical and experiental reearch realized in lat year on the author workplace and oriented to a veriication o thee teel anchor to concrete uing the eect o the echanical interaction o both coponent aterial (teel and concrete). Within the raework o entioned reearch prograe a large nuber o loading tet were perored or variou loading cae and all the reult were equently elaborated to get value o load-carrying capacity correponding dierent ailure echani o thee atener depending on the ued aterial and geoetric paraeter a well a on the type o loading. They were alo realized oe additional loading tet or the veriication o actual aterial propertie o the elected eber (epecially in cae o trength characteritic). ll the data and tet reult obtained ro the perored experient were evaluated uing tatitic and probabilitic approache to get the characteritic and deign value o load-carrying capacity. Thereore, thi article provide oe additional inoration about the general principle o entioned eber or atening a well a it copleent oe author previou plication in thi ield. Keyword Deign paraeter, expanion anchor, ailure ode, load-carrying capacity, loading tet, tenion orce. T I. ITRODUCTIO HEY exit any type o atening yte, where in cae o an application to concrete any kind o the have Thi paper ha been worked out under the project o. LO1408 dmas UP - dvanced Material, Structure and Technologie, upported by Minitry o Education, Youth and Sport under the ational Sutainability Prograe I" and under the project o peciic reearch o. FST-S upported alo by Minitry o Education, Youth and Sport. M. Štrba, Faculty o Civil Engineering, Brno Univerity o Technology, Veveří St. 331/95, 60 00, Brno, Czech Replic, (phone: ; e- ail: trba.@ce.vutbr.cz). M. Karazínová, Faculty o Civil Engineering, Brno Univerity o Technology, Veveří St. 331/95, 60 00, Brno, Czech Replic, (e-ail: karazinova.@ce.vutbr.cz). V. Václavíková, Faculty o Civil Engineering, Brno Univerity o Technology, Veveří St. 331/95, 60 00, Brno, Czech Replic, (e-ail: veronika.vaclavikova@vutbr.cz). widepread ue. However, two ain group o thee eber can be ditinguihed. the irt group they can be taken oe older and ore traditional eber, o-called cat-in-place atener, which have to be alway ued beore the concrete i poured into the orwork. On the contrary, the econd group contain the newer approach, where we can ind o-called pot-intalled eber, which are placed in the concrete ater it hardening. Currently, eber ro the econd group are ued lightly ore oten, epecially becaue o their eaier intallation, which can obviouly caue a ater building proce in general and give an advantage in cae o eriou requireent or an eicient deign and at contruction. Copared to the cat-in-place yte, another reaon or ore requent application o pot-intalled atener can be alo their higher accuracy (which goe in cat-in-place yte together with ore coplicated aebly procedure and higher need or accuracy check). STEEL FSTEERS TO COCRETE - echanical expanion anchor - crew anchor - undercut anchor - other Cat-in-place atening eber - headed bolt - L-bolt and J-bolt - bent rod - traight or bent threaded rod - headed tud welded to teel plate Mechanical type Pot-intalled atening eber Cheical type - bonded anchor with capule yte - bonded anchor with injection yte - bonded undercut anchor Fig. 1 the type o atening ethod to concrete n overview o ot coon type o the teel atener to concrete repreented two entioned group i hown ISS:

2 ITERTIOL JOURL OF MECHICS Volue 1, 018 on Fig. 1, where alo the pot-intalled eber are divided into two group according their peciic technology (i.e. echanical and cheical type). Both naed yte have their own peciic deign and geoetric arrangeent and their type o loading depend otly on their particular ue in contruction [1]. The ain ai o the reearch wa to obtain inoration and experience about the actual behaviour and to get the value o a load-carrying capacity in cae o the pot-intalled echanical anchor jected to tenion loading. lthough thi paper i ocued ainly on the pot-intalled eber, they are on Fig. or better illutration hown alo oe exaple o the entioned cat-in-place atening eber with a decription. For ore exaple ee e.g. []. On the contrary, the echanical one are very ueul, too. Motly becaue their at and eay intallation (no additional binding aterial i needed, iediate loading traner ater intallation and no dependency on weather condition, unlike the cheical type). However thee atener can be ued or dierent kind o loading (hear, tenion, bending oent, etc.), ro now, the attention will be paid only to the echanical eber to concrete ued or tenion orce.. Type o pot-intalled echanical atening eber In cae o thee atener the traner o a tenion orce occur only between the atener itel and the bae concrete aterial. Many type o thee eber exit. For exaple the crew anchor, where the diaeter o the drilled hole d h i lightly aller than the diaeter o the anchor d 0 o that the thread pitche can cut into the concrete urace inide the hole, ee Fig. 3. In act, thi type o echanical anchor ha very iilar principle o load traner to the bonded type (i.e. it ha ore unior orce ditribution along it length). d h d 0 Fig. 3 illutration o the crew anchor Fig. oe exaple o cat-in-place teel atener to concrete (top let the headed bolt; top right the threaded rod welded to the teel plate; botto bent threaded rod cobined with concrete reinorceent) another exaple they can be taken o-called undercut anchor, whoe principle i hown on Fig. 4. In act, or thee eber the pecial drilling equipent ha to be ued (ee tep on Fig. 4) to ake an undercut into a cylindrical hole II. POST-ISTLLED FSTEIG MEMBERS In the ield o pot-intalled anchorage eber they can be ound variou type o the, where alo the poibilitie o their ue are very wide (priarily in the civil and bridge engineering). Generally, two ain type o the can be entioned, according their baic principle. Firtly they are the bonded anchor and then the echanical anchor. The bonded one (cheical type) are lightly ore preerred becaue o their ore available and unior tranerring o tenion orce. Fig. 4 illutration o the undercut anchor ISS:

3 ITERTIOL JOURL OF MECHICS Volue 1, 018 B. Mechanical expanion anchor to concrete However, in practice, the otly ued type o teel potintalled echanical anchor to concrete i an expanion anchor with controlled torque, which uually conit o a teel bolt ued together with the expanion leeve and with the threaded cone (ee Fig. 5). cone III. CTUL BEHVIOUR UDER TESIO LODIG Two ot typical and requent ode o ailure exit in cae o teel echanical expanion anchor to concrete jected to tenion loading orce. The irt one i a ailure o the teel bolt in it threaded part (it i o-called teel-bolt ailure ). In the econd cae the ailure o concrete occur, where the cone o concrete i being tear out ro the concrete bae (thi ailure ode i called concrete-cone ailure ), ee Fig. 6 and Fig. 7. Fig. 5 echanical expanion anchor to concrete By uing o a controlled torque on a bolt head the cone ove into a leeve which open toward the concrete urace and the expanion orce occur. Thi principle together with the principle o the loading traner i hown on Fig. 6, where it i alo added the coparion with the unior loading traner o a typical bonded anchor. ote: it exit alo another type o expanion anchor, which ha controlled diplaceent, but it i not o coonly ued. teel bolt Fig. 7 illutration o ode o ailure in cae o teel echanical expanion anchor to concrete under tenion loading orce; ailure o teel bolt (let) and concrete-cone ailure (right) expanion orce cone h e concrete cone ailure expanion leeve Except entioned two ode they exit alo another, le coon cae, like e.g. the pull-out ailure, where the whole anchor (including the expanion leeve and the cone) i pulled-out ro the concrete. t the ae tie it can be (but not alway) daaged jut all part o concrete on it urace iediately cloe to the anchor (it can occur, in act, a all concrete-cone ailure in thi cae, too). The econd one, alo not very coon ode o ailure i o-called plitting ailure. For ore detail about the ailure ode ee [1]. nut expanion orce threaded rod concrete cone ailure adheive Fig. 6 the principle o loading traner in cae o the echanical expanion anchor (top) and the bonded anchor (botto) IV. LOD-CRRYIG CPCITY I CSE OF THE TESIO. Failure o teel STTIC FORCE Generally, in cae o the teel ailure the value o the ultiate load-carrying capacity o the echanical expanion anchor depend on the teel bolt tenile area (it ean on the diaeter o the bolt d) and on the ultiate trength o teel. It can be taken a ollow: k. (1) The coeicient k in the orula (1) iplie otly the inluence o elected tatitic uncertaintie (or exaple the variability o aterial characteritic and geoetry a well a o the way and condition o an aebly, etc.). Baically, thi coeicient hould reduce the load-carrying capacity. ISS:

4 ITERTIOL JOURL OF MECHICS Volue 1, 018 However, due to oe previou experience and reearche, the coeicient ha uually it value very cloe to the value 1.0. On the bai o 31 previouly perored experient with tatic tenion loading orce, the eleentary orula (1) have been odiied into the or o the ean value o the loadcarrying capacity, a ollow:, () For ore peciic detail about the previouly perored tet o the teel echanical expanion anchor jected to the tatic tenion orce ee [3] [5]. B. Failure o concrete ext, in cae o concrete-cone ailure a ew ethod exit to deterine the load-carrying capacity o expanion anchor under the tenion loading orce. Generally, thi deterination i baed on the ultiate tenile capacity o concrete c, where the eective concrete area c and the concrete tenile trength ct are ued together with poible ue o an additional coeicient k c, which can have (in principle) very iilar eaning like the k actor in the orula (1). c k. (3) c c ct ll the ethod vary according to the ued geoetric paraeter o the anchor and according to the ipliication o the hape o ailed cone o concrete. Thi hape (or or) can be taken or exaple a a cone or a a pyraid. The eective tenile area o concrete change according thi ipliication. In oe ethod the cylindrical trength o concrete i ued, in another ethod the ce trength i ued, etc. However, in each ethod, the ot iportant geoetric paraeter i o-called eective length o the anchor (or the eective depth o the anchor) h e. The geoetric eaning o thi value i hown on Fig. 6). Recently, the ot requent ethod are o-called Concrete- Cone Method [6] and the Concrete-Capacity Method [7]. Baed on 17 previouly perored experient with tatic tenion loading orce, [3] [5], the ean value o the loadcarrying capacity according to the Concrete-Capacity Method can be taken a ollow: c1, he ce150, (4) where the ce150 value i the copreive ce trength eaured and teted on the concrete pecien with the dienion c. Then, according to Concrete- Cone Method the ean value o the load-carrying capacity o the expanion anchor can be deterined thi way: c, he ce150. (5) For ore principle in the event o the concrete cone ailure and or ore peciic explanation o the load-carrying capacity deterination in it cae ee [1] or [8] [10]. C. Eective paraeter in cae o tatic tenion orce On the bai o the deterined orula or the tatic loadcarrying capacitie in cae o both ailure ode it i poible to elect the ot eicient and eective anchorage paraeter (the diaeter o bolt, i.e. the tenile bolt area, then the eective anchorage depth a well a the trength o both ued aterial), o that the probability o the ailure ode o both aterial can be the ae or at leat very iilar. Then, in uch cae, alo the value o load-carrying capacity or the bolt ailure and or the concrete cone ailure could be the ae. Thereore, through the ue o the entioned equation or the ean value o load-carrying capacitie () (4) (5) they can be derived the uitable relationhip between all the paraeter (geoetrical and echanical, ee above), which have the inluence to the reitance. Conequently, according to the elected concrete ailure ethod and baed on the auption, that the ean value o the load-carrying capacitie o both ailure ode hould be equal, i.e.: c1,,, (6) c,,, (7) it can be written the equation or the anchorage paraeter relationhip in cae o the Concrete-Capacity Method thi way: he ce150 (8) and in cae o Concrete-Cone Method a ollow: he ce150. (9) Then, ro the equation (8) and (9) they can be derived value o the correponding eective tenile area o the teel bolt a either: or: 15.6 ce150 ce150 he he, (10) h 1.04 e ce h e ce150. (11) ISS:

5 ITERTIOL JOURL OF MECHICS Volue 1, 018 ext, in Table 1 and the value o tenile teel bolt area according to the orula (10) and (11) are written or oe typical clae o concrete [11] and or one elected value o the ultiate trength o teel = 800 MPa, i.e. or teel bolt grade 8.8 [1]. The graphic illutration o both derived relationhip (10) and (11) or the deterination o the teel bolt tenile area according to Table 1 and are hown on Fig. 8 and Fig. 9, where alo the peciic bolt diaeter are elected and arked a M8, M10 and M1 adequately to their value o. Table 1 deterination o the eective tenile bolt area in cae o Concrete-Capacity Method, i.e. according (10) Fig. 8 relationhip between the eective anchorage depth and tenile area o the teel bolt in cae o Concrete-Capacity Method Table deterination o the eective tenile bolt area in cae o Concrete-Cone Method, i.e. according (11) Fig. 9 relationhip between the eective anchorage depth and tenile area o the teel bolt in cae o Concrete-Cone Method ISS:

6 ITERTIOL JOURL OF MECHICS Volue 1, 018 D. Deign value o eective anchorage paraeter The derived relationhip o the load-carrying capacitie decribed above were alo proceed uing the probabilitic evaluation o the tet reult, i.e. uing the ethod o deign aited by teting given in Eurocode [13]. ote: or the teting the anchor KOTE and Ficher were ued (ee Fig. 10) with the bolt diaeter M8, M10, M1 and M16 and with dierent ultiate trength o teel a well a the concrete block with peciic dienion according the rule given in ETG guideline [14] were ued with dierent copreive trength. For the detailed inoration about the tet arrangeent and about the teel and concrete pecien peciication in cae o the tet with tatic tenion orce ee [8] and [9]. Baed on the probabilitic evaluation uing Deign aited by teting the deign value o the load-carrying capacitie were deterined equentially, irt or the teel-bolt ailure a:, (1) d 0.713, and then in cae o the concrete-cone ailure according to the Concrete-Capacity Method and to the Concrete-Cone Method a ollow: c1, d c1, he ce150 c, d, (13) c, 0. he ce (14) Siilarly a in cae o the ean value ee the evaluation proce in the orula (6) to (11) they could be alo the eective tenile area o teel anchor bolt in their deign value derived either or Concrete-Capacity Method a (15) and or Concrete-Cone Method a (16). ext, alo the illutration o the relationhip (15) and (16) are hown in graph on Fig. 1 and Fig ce150 ce150 he 9.53 he (15) h e ce h e ce150 (16) Fig. 10 exaple o the teel echanical expanion anchor to concrete ued or the loading tet with tenion orce Soe baic rule or the dienion o pecien during loading tet a well a or the poibility o a diplaceent eauring according the ETG [14] are hown on Fig. 11. load cell hydraulic cylinder diplaceent eaureent loading rae teel anchor h e h e h e h e concrete block Fig. 11 geoetric requireent or the loading tet (in dependence o the eective depth he value) Fig. 1 relationhip between and he or the deign value according (15), i.e. according Concrete-Capacity Method ISS:

7 ITERTIOL JOURL OF MECHICS Volue 1, 018 Sequently, they were perored altogether 61 loading tet uing cyclic tenion orce within 6 regular erie o pecien and one pilot erie, where variou elected value o aplitude together with variou cobination o the echanical and geoetric paraeter were ued (ee below). The requency or all tet wa elected a 5 Hz. The echanical anchor with the ultiate trength o teel o 800 MPa (i.e. bolt grade 8.8) and with the bolt diaeter ro 8 to 16 were ued. Then, or the concrete block (pecien) the concrete o the copreive ce trength ro 0.0 to 48.0 MPa wa ued. The eective depth h e wa choen ro 30 to 85. For the teting with the repeated tenion orce the equipent with the hydraulic cylinder type G (by IOV Prague) together with the load cell U5/500 (by HBM) wa ued, ee Fig. 14. Thi equipent and the procedure were iilarly ued alo in cae o the reearch o the tructural detail o teporary teel ootbridge, ee [15] [17]. Fig. 13 relationhip between and he or the deign value according (16), i.e. according Concrete-Cone Method E. Steel echanical anchor under cyclic loading Within the raework o decribed reearch in the ield o teel echanical expanion anchor to concrete alo the loading tet with the ue o cyclic tenion orce were perored. The ain reaon or thee experient wa that thee atening eber could be oten jected to repeated loading. For exaple, in cae o the wind load (where the anchor are ued or the connection o bearing eber or o the acade yte eleent) a well a in the ield o the connection o heavy achinery anchored in the concrete oundation (e.g. preing achine, production line, etc.). However, or thi kind o loading, they are not deined any peciic value (or orula) or the load-carrying capacity. Thereore, one o the poible way how to get thee value can be to peror the loading tet o the elected anchor uing cyclic tenion orce with elected aplitude between the axiu ax and iniu in value: ax in (17) and then to relate all the obtained reult to the previouly derived value o tatic load-carrying capacitie tat in dependence on the inal nuber o loading cycle n tet in the oent o the pecien ailure (18). ote: the two coeicient k and q in (18) repreent the paraeter o an expected atigue curve in cae o repeated loading. ( k log n q) (18) tet tat Fig. 14 illutration o the loading tet o the teel echanical anchor with the cyclic tenion orce During thee tet alo the inluence o the diplaceent o the anchor on the tet reult wa recorded, becaue the total diplaceent ay horten the eective depth o the anchor h e, epecially in the tarting phae o cyclic loading, when the loading orce tart to increae. Thi eect wa partially included in the evaluation proce o the tet reult, ee [18]. an exaple o the reult o the decribed loading tet with the cyclic tenion orce it i a graph on Fig. 15, where it i hown the relationhip between the nuber o cycle n tet and the loading aplitude in cae o all reult, where the teel-bolt ailure occurred. Thereore, in cae o the teel ailure the inal orula o the relation between the deign value o loading aplitude,d and the tatic reitance in dependence o the total nuber o cycle wa derived uing the Deign aited by teting ethod a ollow: ISS:

8 ITERTIOL JOURL OF MECHICS Volue 1, 018, d ( 0.66 log ntet 1.608), ( 0.66 log n tet 1.608). (19) On the lat Fig. 16 they are hown the curve o the border between the concrete-cone ailure and the teel-bolt ailure in cae o cyclic tenion loading, where the concrete ailure have been taken according the Concrete-Cone ethod and the tenile area o the teel bolt wa drown according to (3) or oe elected clae o concrete together with elected nuber o cycle n. They were added, or better illutration, to thi graph alo all the ued diaeter o bolt (M8 to M16). Fig. 15 cyclic tet reult in cae o teel-bolt ailure Siilarly, in cae o concrete ailure they were deterined two orula o the deign value o loading aplitude, i.e. c1,d correponding the Concrete-Capacity Method a (0) and c,d correponding the Concrete-Cone Method a (1). c1, d ( log n ( log n tet tet 0.905) h 0.905) e c1, ce150 (0) c, d 0.51 ( 0.04 log n ( 0.04 log n tet tet 0.893) 0.893) h e c, ce150 (1) Finally, the reulting relationhip were derived or the deterination o an eective value o the tenile teel bolt area o the anchor uing the ae procedure a in cae o loading tet with tatic tenion orce. Firtly, the value in cae o the Concrete-Capacity Method can be taken a: 0.04 log ntet 0.91 he 0.7 log ntet ce150, () or in the ield o the Concrete-Cone Method the relationhip wa deterined a (3). log ntet 0.89 he 0.7 log ntet ce150 (3) V. COCLUSIO Thi article bring oe coprehenive inoration about the loading tet which were perored within recent reearch project on the author workplace in cae o teel echanical anchorage eber under tenion loading. The particular reult (i.e. all the derived orula and relationhip preented above) clearly how the iediate inluence o the geoetric and aterial anchorage paraeter (and their cobination) on the eicient and econoic deign o the teel echanical expanion anchor to concrete in cae o tatic and cyclic tenion loading orce. Fro all the tet reult and ro the derived orula or the tenile area in dependence to the eective anchorage length h e it i obviou, that the teel bolt atigue in cae o repeated loading can inluence the load-carrying capacity uch ore than the characteritic o concrete. ISS:

9 ITERTIOL JOURL OF MECHICS Volue 1, 018 Thereore, on the bai o the orula (15) and (16) they can be choen optial deign value o anchorage paraeter in cae o tatic tenion orce. By uing o the lat orula () and (3) it can be ade the econoic and eicient deign in cae o cyclic tenion loading. Becaue, in general, they are not known the value o the load-carrying capacity in cae o cyclic loading or decribed anchorage eber (except oe deign value o elected developer), it can be ueul thi preented ethod, where they are irtly obtained the tatic (characteritic or deign) value o the load-carrying capacity o thee eber and then they are copared with the cyclic value in dependence o the loading aplitude and o the nuber o cycle to get the load-carrying capacity alo in cae o repeated loading. However, all preented reult were derived ro the relatively all tet nuber, o they ay not be generalized. It i neceary to peror another tet with wider choice o all iportant paraeter and characteritic, which have the direct inluence on the deign o elected pot-intalled anchorage eber. CKOWLEDGMET M. Štrba and M. Karazínová thank to the project o. LO1408 "dmas UP dvanced Material, Structure and Technologie" (part o ational Sutainability Prograe I" upported by Minitry o Education, Youth and Sport) and all the author thank to the project o. FST-S (peciic reearch) upported by Minitry o Education, Youth and Sport. Steel and Concrete, Univerity o Stuttgart, RILEM, 001, pp , ISB X. [8] M. Štrba, M. Karazínová, Uing o the deign aited by teting ethod in cae o the experiental veriication o the load-carrying capacity o expanion anchor, International Journal o Mechanic, orth tlantic Univerity Union, U.S.., Vol. 10, 016, pp. 7-34, ISS [9] M. Štrba, Steel expanion anchor under cyclic tenile loading (original i in the Czech language), PhD Thei, vol. 633, Brno, 011, ISS [10] R. Eligehauen, J. Ožbolt, Size eect in nchorage Behaviour, In Proceeding o the 8th European Conerence on Fracture - Fracture Behavior and Deign o Material and Structure, Torino, [11] E Eurocode : Deign o concrete tructure Part 1-1: General rule or building, CE Bruel, 006. [1] E Eurocode 3: Deign o Steel Structure Part 1-8: Deign o Joint, CE Bruel, 010. [13] E 1990 Eurocode: Bai o Structural Deign, The nnex D: Deign aited by teting, CE Bruel, 004. [14] ETG 001 Guideline or European Technical pproval o Metal nchor or ue in Concrete, EOT (European Organization or Technical pproval), Bruel, 006. [15] M. Štrba, M. Karazínová and P. Sion, The teting ethodology o new developed teel teporary tru ootbridge detail in cae o cyclic loading, In Recent dvance in Civil and Mining Engineering Proceeding o 4th European Conerence o Civil Engineering (ECCIE'13), WSES Pre, ntalya, Turkey, 013, pp , ISS , ISB [16] M. Štrba, On the proble o teting ethodology ued in cae o the teporary teel through tru ootbridge developent, International Journal o Mechanic, orth tlantic Univerity Union, U.S.., Iue, Vol. 7, 013, pp , ISS [17] M. Štrba, M. Karazínová, The developent and teting o a new type o the teporary teel tru ootbridge with cloed cro-ection, International Journal o Mechanic, orth tlantic Univerity Union, U.S.., Vol. 9, 015, pp , ISS [18] M. Štrba, M. Karazínová, ctual behaviour and objective load-carrying capacity o tenion teel expanion anchor to concrete, Procedia Engineering, Elevier, Slovakia, Vol. 40, 01, pp , ISS REFERECES [1] R. Eligehauen, R. Malée and J. F. Silva, nchorage in Concrete Contruction, Ernt & Sohn, GbH, Berlin, 006. ISB [] F. Faltu, Steel Structure o Civil Engineering (original i in the Czech language), Czecholovak cadey o Science Plihing, Prague, 1960, DT [3] M. Karazínová, J. Melcher, M. Štrba, Fatening o teel tructural eber to concrete uing pot-intalled echanical atener, In Proceeding o SCCS 9th International Conerence on Steel Concrete Copoite and Hybrid Structure, Leed, 009, pp ISB [4] M. Štrba, M. Karazínová, On the proble o actual behaviour and load-carrying capacity o teel anchor bolt jected to repeated tenion loading, In Proceeding o 3rd European Conerence o Civil Engineering (ECCIE '1) Recent dvance in Engineering, WSES Pre, Pari, France, 01, pp , ISS , ISB [5] M. Štrba, M. Karazínová, Experiental veriication o load-carrying capacity in cae o teel pot-intalled expanion anchor jected to a tenion loading, In Fluid, Heat and Ma Traner, Mechanical and Civil Engineering - Proceeding o 6th European Conerence o Civil Engineering (ECCIE '15), WSES Pre, Budapet, Hungary, 015, pp , ISS , ISB [6] M. Shirvani, R. E. Klingner, H. L. Grave, Behaviour o tenile anchor in concrete: Statitical analyi and deign recoendation, In Proceeding o the conerence Connection between Steel and Concrete, Univerity o Stuttgart, RILEM 001, pp , ISB X. [7] J. E. Breen, E.-M. Eichinger, W. Fuch, nchoring to concrete: the new CI approach, In Proceeding o the conerence Connection between M. Štrba (M 17) wa born in Třinec, Czech Replic, in He graduated in 00 and got Civil engineering Mater degree. Then, in 011, he got Civil engineering Doctor degree. Both at Brno Univerity o Technology, Faculty o Civil Engineering. Hi ajor ield o tudy wa the deign o teel tructure and building contruction. He ha been working irt a a lecturer and then a an aitant proeor at Brno univerity o Technology, Faculty o Civil Engineering ince 005. He ha plihed ore than 50 paper o ar and participated in any conerence ocued on the civil engineering and on the deign o building and contruction, epecially teel tructure and bridge. ISS: