. : . - - . . - I ce . I OFI ORNL P 3595 .. - * . . 1 . . . . . SEEFEEFE 11:25 1.4 1.6 MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS -1963 . "FEB ? 6 1968 ORNU-P.3595 Conf-680203-02 MORTAR MODELS OF PRESTRESSED CONCRETE REACTOR VESSELS* MASTER James M. Corum, M. AS WEL Richard N. White, M. ASCE Jack E. Smith Abstract The results of the test of a small scale model of & prestressed concrete reactor vessel are presented. Model design and fabrication techniques are discussed, and the test results are compared to finite element analysis predictions for both elastic and short-term creep be- havior. The test reported is the first of a series in a model study program being carried out to determine to what extent small mortar models and models of elastic materials, such as epoxy, can be used to investigate the stress distributions and the cracking and ultimate failure mode of prestressed concrete reactor vessels or of various components of these vessels, such as penetration and anchor regions. OAK RIDGE NATIONAL LABORATORY OAK RIDGE, TENNESSEE LEGAL NOTICE This report wao prepared as an account of Government sponsored work. Neither the United States, oor the Commission, nor any person acting on behalf of the Commission: A. Makes any warranty or representation, expressed or implied, with respect to the accu- racy, completenods, or usefulness of tho information contained in this report, or that the use of any information, apparatus, method, or procos& disclosed in this report may not iafringe privately owned rights; or B. Assumes any liabilities with respect to the use of, or for damages resulting from the Use of any information, apparatus, mctbod, or process disclosed in this report. As usod in the above, "person acting on behalf of the Commission" Includes any am- ployee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Cow.col.sion, or employee of such contractor prepares, disseminatos, or provides access to any information pursuant to die employment or contract with the Commissina, or his employmont with such contractor. Research sponsored by the U. S. Atomic Energy Commission under contract with the Union Carbide Corporation. *Reactor Division, Oak Ridge National Laboratory. 2 Associate Professor of Structural Engineering, Cornell University, ...Ithaca, New York (currently on leave with Gulf General Atomic, Inc.). VAL 126 RT iF DOTMAMOM ( THIS DOCUMUUS UNUMI t .* . US TY mampu menguranganyarors PHOTOS AND ****.puen . . INTRODUCTION · The study described in this paper represents a portion of a major program of investigation into the use of prestressed concrete reactor vessels (hereafter referred to as the PCRV). The overall program is being directed by the Oak Ridge National Laboratory for the United States Atomic Energy Commission and is directed specifically at improving the level of technology for the design, analysis, and construction of PCRV structures. Because of the great complexity of this type of structure, model analysis has played an important role in the design phases for the several European PCRV's built in recent years(b). Most of these models have been rather large structures in themselves and have been quite expensive. Large models have also been used in the U.s. (2) in studies preliminary to the design of the first PCRV to be built in this country. : The purpose of the study reported herein is to determine the suitability and accuracy of very small scale models for de- termining certain behavioral aspects of the PCRV. Experience with small scale models of other types of concrete structures!" indicates that response to elastic loadings (prestressing, working pressure) and inelastic behavior (short-term creep, degree of cracking at overpressures, mode of failure, and ultimate strength) might well be investigated economically with this technique. Thermal effects and long-time inelastic behavior were considered to be beyond the scope of this initial study. The role of the small mortar model in the current study is shown in Fig. 1. The larger structure is a relatively small 11 , -lo . 2.75 and simple "prototype" prestressed concrete vessel; it repre- sents the top half of a cylindrical vessel closed with flat heads. A full size PCRV would be on the order of 8 times larger than this structure. The prototype will be tested to failure under internal hydraulic pressure at a later date and will provide experimental results for direct conparison to the smaller mortar models, which are also shown in Fig. 1. The two nortar models are exact replicas of the concrete models at a geometrựcal scale .. The pneumatic pressure test of the first mortar model is described in this paper. The second mortar model was tested hydraulically; detailed results of this most recent test are not yet available. The final model shown in Fig. 1 is a 1/5 scale prestressed epoxy model which is to be analyzed by the scattered-light three- dimensional photoelasticity technique. It will provide an elastic stress distribution for prestressing and pressure loadings. DESCRIPTION OF PROTOTYPE The design of the prototype vessel is sion in Fig. 2. The vessel has many features similar to those found in an actual PURV, including thick head and walls, unbonded post-teasioned prestres- sing in three directions to counteract the effects of internal pressure, and a pattern of penetrations through the head. The only conventional reinforcing elegents in the structure are the two concentric rings of steel aesh at the base, and 8:0911 pieces of mesn under the prestressing anchor plates in the head. The prototype was designed for 500 psi internal pressure, which is representative of pressures act in actual gas-cooled -2- ... . .. - -- - - ..- n reactors. A concrete vith noniaal uniaxial compressive strengta of 6000 psi was used, and ali prestressing elements were con- ventional Stressteel bars. A fiber-glass reinforced epoxy liner was applied to the interior cavity of the vessel to prevent permeation of the pressurization fluid into the concrete. A finite element analysis program developed at Gulf General Atomic, Inc. (4) for the AEC was used in the design of the proto- type. The axisymmetric idealization of the strucüure is shows in Fig. 3; the concrete and steel buse plate are represented by triangular ring elements. Linear eleaents are used for convento ional reinforcement and prestressing loads are idealized as externally applied point loads. The effect of head penetrations is accounted for by reducing the stiffness of the penetration region. Principal stress trajectories for the case of prestressing plus 500 psi design pressure are shown in Fig. 4. Figs. 5 and 6 give stress contour plots for circumferential (hoop) aos meridional stresses, respectively. At the design pressure of 500 psi, the average hoop stress is about 500 psi compression. Since each additional 100 jsi of pressure adds a tensile stress of about 200 psi, the average hoop stress will become about 500 psi tension at an internal pressure of 1000 psi. The imperfections of the idealized mathematical model (in particular, the stress concen- trations produced at the 12 axial prestressing tend on conduits) will lead to somewhat higher local hoop stress, and the cracking strength of the concrete should be exceede i at this pressure . The maximum meridional stresses of Fig. 6 beco:ne more posa. - -- L , 'LLAR ., . . nm , T.- UNUTYPE tat de contaminante temperamente metasta in die mind that international entarios en portes obertemu penawan .: 11 m PEARS . -3 co : :A . . TA o itive with increasing internal pressure. The haunch area, where the head and wall join together, will become critically stressed in tension with increasing pressure. The high localized con- pressive stresses under the hoop prestressing load points do not exist in the true vessel because the prestressing is dis- tributed through steel anchor blocks (Fig. 2). In addition to the axisynmetric analysis, the stress con- centrations around the head penetrations were assessed by a planar finite element analysis of the head. MORTAR MODELS Similitude and Materials: All geometrical features of the proto- type were reduced by a scale factor of 2.75. Model materials were chosen to duplicate prototype material properties as closely as possible. The resulting mortar models can thus be coneidered a's true models of the prototype, with strains and stresses ident- ical in model and prototype at any given internal pressure level. The mortar mix proportions were 1:3:1 (cenent, sand, 5/16" aggregate) with a water/cement ratio of 0.517. A typical com- pressive stress-strain curve from a 2 in. by 4 in. cylinder is shown in Fig. 7; average 28 day f: was 6.83 ksi. Stressteel rods were used for prestressing the model, and a suitably scaled mild steel mesh was used for base reinforcing and under the prestressing anchor plates. Fabrication and Casting of Model: The production of high quality models of this complexity and at a very small scale requires extremely careful planning and workuanship at all stages of fabrication and casting. 4. Plexiglas was chosen as the basic forming material because of its superior qualities -- it is easily machined to close tolerances, does not absorb .water, produces excellent surfaces, and permits multiple re-use of forms without deterioration. Part of the exterior base mold and a number of steel hardware items are shown in Fig. 8. The interior cavity mold was constructed of aluminum tubing with a Plexiglas top plate. The entire assembly (visible in Fig. 9) was cut into three segments to enable removal from the cavity after casting. ' This form is also re-usable. A partial assembly of the form is showa in Fig. 9. The steel anchor blocks were held in position by attaching them to the exterior walls of the form, and Plexiglas filler blocks were inserted between the steel blocks to form the required irregular hexagonal exterior surfaces of the model wall. Caulking compound was used extensively in building up a water-tight assemblage of woma. c n intensies blocks. annis samen met klein in the upper redan har m A top view of the completed form is shown in Fig. 10 just prior to model casting. The congestion of the many internal com- ponents severely restricted placedent of the mortar. The entire mold was vibrated intermittently during place. ment of mortar (Fig. 11) over a 45 minute casting period. The placing of the low-slump nortar in the congested form would have been impossible without the vibrating table. The transparency of. the Plexiglas forms was invaluable in assessing the adequacy of the vibration. Removal of interior and exterior forms was accomplished -50 . according to a pre-determined schedule. at an early age (22 hours or less) to prevent the possibility of restrained early shrinkage producing cracking in the model. The resulting models were of very high quality with neg- ligible voids or boney-coabing. A disassembled model is shown in Fig. 12. Typical axial, head, and circumferential prestres- sing bars are shown in the foregrour1. The base plate is shown on the right with tie-rods connected to the head penetration plugs. The models were cured in a fog room for about fc:r weeks.: After removal a ad a brief drying period, the surfaces of the model were sealed with several coats of shellac. The models were kept in a controlled enviroanent (70° F, and 50% R.H.) during the instru nentation and testing period. The first model was instrumented with 70 strain gages, crack detecting strips, and transducers; the second mortar model and the prototype had about 370 separation instrumcntation points. Model Prestressing: The models were prestressed using convent- ional jacking equipment. Six rams (Fig. 13) connected to a common hydraulic pressure source were used to prestress six tendons simultaneously. The prestressing was accomplished in two phases with all tendons stressed to half the final load level in the first phase. No difficulties were met in achieving an accurate. level of prestress in these very short tendons. TEST RESULTS AND COMPARISONS Testinz History: Following a four week creep test period after prestressing, the first model was pressurized with nitrogen For . ********........... LAK according to the schedule shown in fig. 14. After 3 pressure cycles (to 300, 300,, and 600. psi) of elastic loading response, the vessel was subjected to a higher pressure level which ended with a leak in the epoxy liner at 850 psi. Tae leak was repaired and the vessel was pressurized again, reaching 965 psi before significant structural cracking and sudden leaking occurred. The only apparent evidence of failure was a sudden drop in pressure and the loud hissing of escaping gas. The vessel was then filled with oil and pressurized to 1045 psi, which was more than 2.5 times the working pressure of 417 psi. Oil was observed to be leaking from at least several major vertical hoop cracks in the cylindrical portion of the vessel. Comparison of Results with Elastic Analysis: Measured and pre- dicted meridional and circunfercatial stresses for a gage rosette near the iaside center of the vessel wall are shown in Fig. 15. " * . . Two different short-time load ings are given -- the prestressing sequence and the pressure cycling shown in Fig. 14 up to a pressure of 800 psi. The solid steps are finite element pre- dictions while the points are experimental results. The agree nent for meridional stresses is excellent at all load levels. Cir- cumferential stresses for the pressure test agree less favor- ably; this is most likely due to the non-axisymmetric cross section which would have a pronounced effect on circumferential stresses. Stress conparisons for a location in the baunch area of the vessel are shown in Fig. 16. Notice that once again the computed meridional stresses are very close to measured values, while circumferential stresses show significant differences. i - w ; -7 Fig. 17 gives results for a rosette in the top head penetration region. The theoretical predictions here are a analysis of the penetration region. The elastic response of the prestressing tendons during vessel pressurization was measured and also computed in the analysis of another idealization of the vessel which included the tendons in the structural stiffness matrix. The tendon stress increases were as follows: Specific Stress (psi_per_psi pressure) Tendon Measured Computed 1.47 5.07 Axial 2.80 3.03 Head 1.60 Circumferential - 8.27 It is believed that the relatively poor agreement between the values for circumferential tendons may be due to the effects of including only the upper portion of the actual vessel in the idealization; a roller support permitting radial displacements was placed in the cut wall. These assumed boundary conditions would affect circumfere ht, a 1 1 tendon's much more than axial or 4 head tendons. Inelastic Behavior: Inelastic behavior may be divided into two phases: (a) concrete creep and prestressing steel relaxation under relatively constant loading conditions, and (b) cracking behavior under high pressure levels. Measured strains during the one-month creep test at three gage locations are shown by the dashed lines in Fig. 18. The only loading on the vessel was the prestressing. It may be : -S- assumed that the strain changes are due. entirely to creep.. . since the model surfaces were sealed against.moisture exchange with the atmosphere. The measured change in the axial prestressing bar strain is also shown in this Figure. Note the two strain levels cor- responding to 60% and 70% of the minimum ultimate tendon strength. The first value represents the design level and the second the maximum allowable level during prestressing. The computed response curves shown in Fig. 18 were deter- mined with another finite element program; this linear visco- elastic creep analysis procedure is described in Ref. 5. The idealization used was the same as used in determining the elastic response of the prestressing tendons during vessel pres- surization (described above). Because the creep function used was only approximate , the results from the analysis and the test cannot be expected to compare directly. The analysis results would improve with a more detailed knowledge of the mortar creep properties available as input to the analysis. Relaxation effects in the prestressing steel was accounted for in the analysis by assuming that the steel stress level would reduce by 4% (linearly with respect to logarithm of time) during the creep period. . The extensive cracking of the structure under high pressure was revealed by the patterns of oil leakage. After the fina). pressurization test the prestressing tendons were removed and the model was pressurized with tap water at 75 psi. Fig. 19 shows the water leakage which duplicated the pattern of oil leakage observed during the test. Note the two main vertical ' -- ... e se esconder w omen have reasonsai ' . -. -. . - .-IY # #. .. ..... . .. .. .. ... Viti i it. ili - at " .11 .. cracks, especially the one just to the ſight of the left anchor blocks. Following the water test, the model was sectioned just below its midplane, and the top half of the vessel is shown in Fig. 20. The dark traces through the wall were caused by oil leaking through the many hoop cracks in the vessel. The stress raising effects of the axial tendon conduits are clearly visible from the cracking pattern which developed. . There were also some cracks running circumferentially around the haunch. Fig. 21 shows a vertical crack which forks at the haunch into two circumferential cracks. There undoubtedly were many other small interior cracks which were not detected either by inspection or by the instrumentation. Soue indication of the pressure level producing the init- iation of cracks is provided by the strain plots in Figs. 22, 23, and 24. These results are from 5 in. long crack detection strips which were actually single wire strain gages. The first figure is for a circumferential gage which picked up indications of hoop-type cracking. At a pressure of just over 800 psi the strain suddenly increased rapidly, thus marking the initiation of hoop-type cracking. Fig. 23 presents results for a neridional gage in the .. haunch area of the PCRV. Notice that there is no sign of cracking on the first pressurization to 850 psi, but some cracking appar- ently occurred at a pressure between 500 and 600 psi during the subsequent pressurization. The results froin a meridional gage in the cylindrical portion -10- R T '-:r .. - r - - - .rry- -- --- - - -- -- -- of the vessel are given in Fig. 24. There is no indication of cracking except near the ultimate pressure of 1045 psi. DISCUSSION AND CONCLUSIONS 1. The failure of this type of vessel is gradual and is accomp- anied by extensive cracking which in turn relieves, the internal pressure. The integrity of the liner is an important feature of the vessel in reaching high pressure levels. The ductility of the structure is assured by the proper amounts and placement of prestressing steel. 2. The final assessment of the validity of the very small scale modeling technique will be possible only after testing of the larger prototype vessel is completed. Preliminary comparison of results from the two identical mortar models indicates excel- lent reproducibility of behavior, and the final comparison of results is being approached with considerable optimism for success. 3. Considerable thought and care are required at all stages of construction and instrumentation of very small structures of this complexity. 4. Considering the complexity of the PCRV, the finite element analysis techniques provide excellent prediction of vessel be- havior, particularly in the elastic range. Developments currently under way will extend the analysis capability into cracking and post-cracking behavior. Detailed comparisons of actual test structure behavior, such as described herein, with the computer predictions are essential in developnent of the analysis programs. :-1l- : ACKNOWLEDGEMENTS The mortar models and their forms and accessories were designed and built at Cornell University under a sub-contract from the Union Carbide Corporation. Structure instrumentation and testing was done at Oak Ridge National Laboratory. Computer time for a portion of the analysis was provided by · Gulf Gen- eral Atomic Inc. ; most of the elastic analysis was done in the Computer Center at ORNL. REFERENCES '1. Group G Papers (Models--Comparison of Theory With Experi- mental Results), Conference on Prestressed Concrete Pressure Vessels, London, March 1967. 2. "Pressure Test and Evaluation of a Model Pressure Vessel," by W. Rockenhauser, T.E. Northup, and R.O. Marsh, Paper 38, London Conference on PCRV's, March 1967. . "Smal) Scale Models of Reinforced and Prestressed Concrete Structures," by H.G. Harris, G.M. Sabnis, and R.N. White, Dept. of Structural Engineering Report No. 326, Cornell University, Ithaca, N.Y. September 1966. .4. "Analysis of Axisymmetric Composite Structure by the Finite Element Method," By Y.R. Rashid, Nuclear Engineering Design, January 1966, pp. 164-182. 5. "Pressure Vessel Analysis by Finite Element Techniques," by Y.R. Rashid and W. Rockenhauser, Paper 37, London Con- ference on PCRV'S, March 1967. -22 -12 wa mwanae ameo entre .. -.--.****** ** ** * **** 4 :13 *T u i n . .. , in A .. !..*.*** .** rin ORNL-DWG 67-8564R 14 16 in. HEAD THICKNESS 7518 iz. MINIMUM WALL THICKNESS 48 in. ACROSS FLATS t 'lg-in. diam BARS 13/-in. diam BARS. : :: :: -60 in. --- . 010 A 50 bo de 4.02 in. HEAD THICKNESS . 2.77 in. MINIMUM WALL THICKNESS 17.46 in. ACROSS FLATS _ 0.409-in. diam BARS Tr 0.5-in. diam BARS ..... . : 2 9.6 in. ACROSS FLATS T101 . . 21.82 in. X 101 WOWOWerorangan OIO over WT. m o ''Vervorom ODO NO.1 (PNEUMATIC FAILURE TEST) NO. 2 (HYDRAULIC FAILURE TEST) CONCRETE "PROTOTYPE“ MODEL (HYDRAULIC FAILURE TEST) MORTAR MODELS (1/2.75 SCALE) EPOXY "ELASTIC" MODEL (ESCALE) FIG. 1. PROTOTYPE AND MODEL VESSELS. Omm-Omg -1037SR SCHED OO ACCESS PIPE FOR NSTRUMENTATION AND PRESSURIZATION - 12 AXIAL BARS, 140 dion STRESSTEEL 144,000 lb MIN. UU. STRENGTH 24 CIRCUMFERENTIAL BARS, in dom STRESSTEEL 215,00016 MIN. ULI STRENGTH -STRESSTEEL HOWLETT GRIP NUT ANCHORAGE STRESSTEEL NUT AND THREAD ANCHORAGES wordenadores para meninas . SCO -- 48 ACROSS FLATS- TI ca ITION LI -6 HEAD BARS, 1 dlom STRESSTEEL 21.4,000 lb MIN. ULT. STRENGTH NOTE: ALL DIMENSIONS ARE IN INCHES -66 dhorn PLATE FIG. 2. PROTOTYPE VESSEL DDEKSIORS AND DESIGN. ORNL-DWG 67-4346 -24.0- SECTION OF REDUCED STIFFNESS 11.0625 16.375 -64.54 M . 53.4375- M - 3.75 +-2.0 AN WW WWW WWW. -4.5 tot 1.25 W WM W -33.0 FIG. 3. AXISYMMETRIC FINITE ELEMENT ANALYSIS IDEALIZATION. ORNL-DWG 67-4345 0 be - MAX. PRINCIPAL STRESS TRAJECTORY -- MIN. PRINCIPAL STRESS TRAJECTORY HALLIT FIG. 4. PRINCIPAL STRESS TRAJECTORIES – PRESTRESSING PLUS 500 PSI PRESSURE. ORNL-OWO 67-4349 SECTION OF REDUCED STIFFNESS 200 X-400 / / --600 --Ban -800 -1000 - 800 per STRESS LEVELS: 3000 2000 1500 4000 500 400 300 200 100 -200 -400 -600 -800 -1009 - 1500 -2000 -2500 • 200- 1500-100000000 - 1000 N00020001500 FIG. 5. CIRCUMFERENTIAL STRESSES - PRESTRESSING PLUS 500 PSI PRESSURE. 0 1 ORNL-DWG 67-4351 SECTION OF REDUCED STIFFNESS 009 3200 1-400 9000 *600 1500 S -1000 <-200- 200 STRESS LEVELS: (-600 S-800 3000 2000 1500 1000 500 400 300 200 100 002- -600 800 -200 -400 -600 -800 - 1000 -1500 -2000 -2500 600 2004 100 500 800 -400 2000 500 -1000 2200 1500- 1000- 1000- 3000 2000 000 100 200 100 mm 2 . -6004 A -600 1-400 -1000 -2000 " " . FIG. 6. MAXIMUM STRESSES IN MERIDIONAL PLANE – PRESTRESSING PLUS 500 PSI PRESSURE. , . .. ..... . ..-. . ........................ .. . . ... .. .. .... ..... . .. .. . ... medit . .... . . STRESS, ksi: W . . . N zt 5 a ' .. . P FIG. 7. STRESS-STRAIN CURVE FOR MORTAR. 0.001 STRAIN 0.002 wn o 0.003 hindi movie there t 28 day te MODEL 1 latest el e . htii hely Eyed here that there the wh e L LAULAVAi 1. . . . . - _ in USA . in Cta. .. L s id a prin internet to make is with the v 2 communication in the minds ا ,بر را .. ا انسان اتنی ............ امممم ت ضمنه من نه من خنه غير عندن- . :: . . . .... .... ...... مردانه دانه "ف.. سنه 1 2 ..--. -- .- : هه وه ... منم ، م - .م.من نه ، ہے مند . معنتسلمنشمندی مه و ۰۰ , ۰۰۰ . 3 5 سنه 4 :: 6 7 "8 موج۱۰۰ دهه ۶ ۰ ۰۰۰ بس .. ..... ... ... .. هنعحممممممنم من و ............ ....... ..... "11":"16" FIG. 8. COMPONENTS OF MODEL AND FORM.. م = | اور : " ب سینه ۲۰۰ : به ۶-۰۳,"": : "":: """:.:. لما بداننده ه ستند. هنمنننهمنننننننخند کدامنمممم - ........ ::. " " * . . . :: .؟ وہ خ اندان مختلف نشان نه د افغانان د . خا»: دشة دهندگان : نویسنده نه ده ...... | مسمن بشن بعهده شده است، منر نقد ش ده معناشدخه منند " . . . . . . مون . . ه به و ۹۰۰ مره.. ۹ سالمنمنم شبنم د -: -.:: اة : بدهند. -و با . - ،: همه .... .... ... هه هه . شه ... ... ... ... و ادامه دهنده : وهمند ۱۰۱۰۰۰۰ ۰۰ مرد , مه مه . .. ....دله . . .... مم ، * و . و تل ۰۰۰۰۰۰ . . . . . . . . . . . ه . "" - و ما ه ) مما منه ، . . ........ . . . نعمت الله نظ؛ لم نسمعنمننا سنسننننسمند همه مینمه مننه : س ب با . او ن .. مندند. . " ب .. . نشي ------........... ...... . ا * قمص. م. ممد۔ ، ما نفسه سنة س سس .. .. ستظن .. .. سی ... .. .. .. ممممممممممم همه .ا . . ... ... . :.:. . . ::: | ل . : 1 و . . . . . . - . . : و الشنار.. 2. .. !!.10''و الفش لنا .. ... . 7 6 5 4 3 17 . . 3 ... 2 به 3:14 15 16 .. :: | '! 1 ... ..... .......- . ... ... ... ....... ... .... وو این همه مفسخه مننننندنفننم ننشستمنحنننننننننننن FIG. 9. PARTIALLY ASSEMBLED FORM. . ار من : لا ، .. TOP VIEW OF FORM AND COMPONENTS. 7 بی :درد هنر ، . . ..... ..ه , , , (ج , FIG. 10. ن سیت سنسند سینه شسسسسست - .. . .۰ مدام همنفسنشد : سلام .-- مع م | | : : T \ ار تل دربا ره ما in .. معلومه مدل ."ه .. میشه .. ... ... .. . . ...... نمي هننمنمة مضنتنتنممنننمننلسنن نعت :: : عمو می.جب تونية منها. سهن ، و نمونه متن عهده ... ۰۰ , ۰ ---ي - ............. . -: ..:.. . .. و . .... ها . ... . زن دادند. من . . 5- . . 8 ''15: ... - مدد ۔ سمسمنة .. . . .. . . همه مه . . : همه لی مه ته ... ...... ماسه نهم مممم م ۰۱۰ : سعد حصصهم.. مهم ترین - . م . . . . . و قوله ته FIG. 11. FORM IN POSITION FOR CASTING MODEL. . Ar viwawar . . 1 . 193," . die verstaan en fu •. ..ii. het **** move your e 2:53 R .. .. .. ... . .. . .. . . .. .. . .. . .. .. .. FIG. 12. MODEL WITH PRESTRESSING ELEMENTS (DISASSEMBLED). con himsediments soient and many more internet o wwwwwwww borony ...www. r ho hatte . - Thai 1. ** . nowi 1 : FIG. 13. PRESTRESSING OPERATION. i... 2 . tibilitat i continua 1 ::.. and may 13 1 Santiago ** *... t . re . birini solo in cui si rasmissioni di milioni malaman namin na miesto . Rose AS. MAX. TEST PRESSURE 965 psic MAX. PNEUMATIC PRESSURE 850 psi - INITIAL LINGE LEAK INTERNAL PRESSURE psi INITIAL CYCLING INCREASE TO TEST PEESSIIRE FAILURE TEST HYDRAULIC .. PNEWMDiv TESTING FIG. 14. PRESSURB LBST HISTORY, MOKTAR MODEL NO. 1. ORNL-DWG 67-8568 500 MERIDIONAL STRESSES (psi) 1000 TomTom 0 GAGE C209 500 CIRCUMFERENTIAL STRESSES (psi) 00 500 PRESTRESSING SEQUENCE PRESSURE TESTS FIG. 15. PREDICTED AND MEASURED STRESSES IN VESSEL WALL. -2000 ORNL-DWG 67-8569 .-1500 -500 MERIDIONAL STRESS (psi) 1000 4500 -2500 GAGE C244 130 CIRCUMFERENTIAL STRESS (psi) Ir. H . 000 500 PRESTRESSING SEQUENCE PRESSURE TESTS FIG. 16. PREDICTED AND MEASURED STRESSES IN HAUNCH AREA. ---..... .. --- ..... .. ........... ---- -- - -- - - - - - - - - - - . . -- - -- - - ORNL-DWG 67-8570R -2000 -1500 -1000 00 MERIDIONAL STRESS (psi) 00 500 GAGE C219 500 CIRCUMFERENTIAL STRESS (psi) DOO -500 500 PRESTRESSING SEQUENCE PRESSURE TESTS FIG. 17. PREDICTED AND MEASURED STRESSES IN VESSEL HEAD. 2. CONCRETE GAGE.. LOCATIONS : 3600 215 2137 zanel SÝRAIN_CORRESPONDING 70 0.ZĘ : 1. MEASURES AVER.96E OF 4 AXIAL TENDONS : 5.95" 2 COMPUTED STRAIN CORRESPONDING TO O.GE CONCRETE GAGE 209 (MERIDIONAL) COMPUTED STRAIN (MIC20-1/..) CONCRETE GAGE 215( MERIDIONAL) COMPLATES " --- 1 -- CONCRETE GAGE 213 (Hoop) . ---------------- ? computed -5001 1 60 64 82 68 72 76 80 84 AGE IN DAYS 88 . FIG. 18. TYPICAL TIME-DEPENDENT STRAINS, PREDICTED AND MEASURED. ..:: PULS. SAT mais 1. . women . . women and .. · .. oir . - . -' . wwwmatamaskine ! - Lt.' 3 1 ... FIG. 19. VESSEL LEAKAGE PATTERNS AT FAILURE. n . image . el seme .. . in ).... . - . . - .. a ..!! . ' ibi .17 . 7 - :. .:, izvor .: . - . . . L and more 12 som en FIG. 20. VERTICAL CRACKING IN · VESSEL WALL. -7 , I 1 *... . In: . . . die wat . wiwit mein Intimodismini wa's indemnizatiini minim eniminenteineriai. Miminations, in the traindik ............. : . : :: :: : : :: سنن ننت . او را ،میر در و . . . و . ; ی هنر : :مه : :..:: .., . . . . . . . نحننننننن CRACKING IN HAUNCH AREA. عننمسیسی.بعدشمنا ORAL-DWG 67-8565 . . * * .W CRACK DETECTION GAGE, S002 . H .100 pin./in. - - eneam-*7*thern* venins INTERNAL PRESSURE (psi) t t u vir I* *** ***htal 144 *044 mwah 0 0 0 STRAIN (min./in.) FIG. 22. RESULTS FOR CIRCUMFERENTIAL CRACK DETECTION STRIP. . 49 VLOTI HL ORNL-DWG 67-8567 ********** *****. CRACK DETECTION GAGE, S302 200 200 min./in. .. i .... -----..-...... INTERNAL PRESSURE (psi) 0 0 0 0 0 STRAIN (min./in.) FIG. 23. RESULTS FOR MERIDIONAL CRACK DETECTION STRIP ACROSS HAUNCH. : within f evening to s o n this materiame financiamento entrenamiento interes istiane f cute kada se nekim Sinondationin rekisteriseret natukemiisimaison avere una sola merastamine midis ording the contra intentio L-DWG 67-8566 AVIATUL 200 min./in. CRACK DETECTION - GAGE, S101 INTERNAL PRESSURE (psi) 0 0 0 STRAIN (rin./in.) .. . . . . .... FIG. 24. RESULTS FOR MERIDIONAL CRACK DETECTION STRIP ON VESSEL WALL. wit * UNE DATE FILMED 4 / 3 / 68 2. 1 14 T . . ·