TESTING AND EVALUATION OF A MODIFIED STEEL POST W-BEAM GUARDRAIL WITH RECYCLED POLYETHYLENE BLOCKOUTS

Transcription

1 TEXAS TRANSPORTATON NSTTUTE TESTNG AND EVALUATON OF A MODFED STEEL POST W-BEAM GUARDRAL WTH RECYCLED POLYETHYLENE BLOCKOUTS by Roger P. Bligh Assistant Research Engineer and Wanda L. Menges Associate Research Specialist Project MPT Sponsored by Mondo Polymer Technologies, nc. FEBRUARY 1997 TEXAS TRANSPORTATON NSTTUTE THE TEXAS A & M UNVERSTY SYSTEM COLLEGE STATON, TEXAS

2 DSCLAMER The contents of this report reflect the views of the authors who are solely responsible for the facts and accuracy of the data, and the opinions, findings and conclusions presented herein. The contents do not necessarily reflect the official views or policies of the Mondo Polymer Technologies, nc., Texas Transportation nstitute, or Texas A&M University. This report does not constitute a standard, specification, or regulation. n addition, the above listed agencies assume no liability for its contents or use thereof. The names of specific products or manufacturers listed herein does not imply endorsement of those products or manufacturers.

3 . ~port No. 2. Oe.wemmen1 Acccu.ion No. 3. Recipient's Catalog Ntt. FHWA-RD Title and Subtille $. Report Date TESTNG AND EVALUATON OF A MODFED STEEL POST W-BEAM GUARDRAL WTH RECYCLED POLYETHYLENE BLOCKOUTS TECHNCAL REPORT DOCUMENTATON PAGE FEBRUARY Perfonning OrgMization Code 7. Author( ) 8. Performing Q<pniutton Report No. Roger P. Bligh and Wanda L. Menges MPT 9. Performing Organi7..ation Namo and Addtest 10. Wort Unit No. Texas Transportation nstitute The Texas A&M University System College Station, Texas NCPNo.. Contract ot Grant No. 11. Spon!Oring Agency Name and Addre Type of Report nd Period Con~rl.'d Mondo Polymer Technologies, nc. Final Report State Route 7 October 1996 through January 1997 P.O. Box SJ!onsoring A.StneY Code Reno, Ohio S. S lflrkmcntlll')' Note Name of contacting representative of Mondo Polymer Technologies, nc.: David L. Tarrant Plant Manager 16. Ab:~tnlct The Federal Highway Administration (FHWA) has formally adopted National Cooperative Highway Research Program (NCHRP) Report 350 as the new performance evaluation guidelines for highway safety featur~s. When tested according to these new guidelines, the widely used G4(1S) steel post, W-beam guardrail system failed to meet the relevant evaluation criteria. This report presents the results of a crash test on a modified G4(1 S) steel post, W-bearn guardrail system with recycled polyethylene blockouts. The recycled polyethylene blockout was judged to have met the evaluation criteria of NCHRP Report 350. This new blockout is considered suitable for use in both steel post and wood post guardrail systems. 11, Key Word.t: 13. l)i.,tribulion Statement guardrails, offset blocks, blockouts, recycled materials, polyethylene, roadside safety, crash testing No restriction. This document, if published, is available to the public through National Technical nformation Service, 5285 Port Royal Road, Springfield, Virginia Sec.wity Clu.1if. (al thit report) 20. Secwily <.1assi(, (o( thit pege) 21. No. of Pase ll. Price Unclassified Unclassified 43 Form DOT F (8-69)

4 51* (MODERN METRC) CONVERSON FACTORS APPROXMATE CONVERSONS TO 51 UNTS APPROXMATE CONVERSONS FROM 51 UNTS Symbol When You Know Multiply by To Find Symbol Symbol When You Know Multiply by To Find Symbol LENGlll L.ENGlll in inches 25.4 millimeters mm mm millimeters inches in ft feet meters m m meters 3.28 f eet ft yd yards meters m m meters 1.09 yards yd mi miles 1.61 kilometers km km kilometers miles mi AREA AREA in 2 square inches square millimeters mm 2 mm 2 square millimeters square inches in 2 ft2 square feet square meters mz mz square meters square feet ft2 yd2 square yards square meters mz mz square meters square yards yd2 ac acres hectares ha ha hectares 2.47 acres ac mi 2 square miles 2.59 square kilometers km 2 km 2 square kilometers square miles mi 2 VOLUME VOLUME fl oz fluid ounces milliliters ml ml milliliters fluid ounces fl oz gal gallons liters L L liters gallons gal ft3 cubic feet cubic meters m3 m3 cubic meters cubic feet ft3 - yd' cubic yards cubic meters m3 m3 cubic meters cubic yards yd3 NOTE: Volumes greater than 1000 shall be shown in m 3. - MASS oz ounces grams g g grams ounces oz lb pounds kilograms kg kg kilograms pounds lb T short tons megagrams Mg Mg megagrams short tons T (2000 lbl (or "metric ton") lor "t"l (or t"l (or "metric ton") lbl MASS TEMPERATURE (exact ) TEMPERATURE (exact) Of Fahrenheit 51F-321/9 or Celcius oc oc Celcius 1.8C+32 Fahrenheit Of temperature F-321/1.8 temperature temperature temperature LLUMNATlON LLUMNATlON fc foot-candles lux lx lx lux foot-candles fc fl foot-lamberts candela/m 2 cd/m 2 cd/m 2 candela/m foot-lamberts fl FORCE and PRESSURE or STRESS FORCE and PRESSURE or STRESS lbf poundforce 4.45 newtons N N newtons poundforce lbf lbf/in 2 poundforce per 6.89 kilopascals kpa kpa kilopascals poundforce per lbf/in 2 square inch square inch Rev1se September 19

5 TABLE OF CONTENTS. NTRODUCTON o o o o 0 o ll. STUDY APPROACH o o o o o o TEST ARTCLE.. o 0 0 o FULL-SCALE CRASH TESTNG 0 o o mpact Conditions NCHRP Report 350 Evaluation Criteria CRASH TEST AND DATA ANALYSS PROCEDURES... 9 Electronic nstrumentation and Data Processing Anthropomorphic Dummy nstrumentation Photographic nstrumentation and Data Processing Test Vehicle Propulsion and Guidance ll. CRASH TEST RESULTS TEST MPTl (NCHRP Report 350 Test Designation 3-11) Test Description Damage to Test nstallation Vehicle Damage Occupant Risk Values V. SUMMARY OF FNDNGS AND CONCLUSONS... 0 SUMMARY OF FNDNGS CONCLUSONS APPENDX A - SOL TESTNG APPENDX B - PROPERTES OF RECYCLED POLYETHYLENE BLOCKOUT.. 35 REFERENCES

6 LST OF FGURES Figure No. Page 1 Cross section of modified guardrail system Details of recycled polyethylene offset block Layout of the modified steel post w-beam guardrail with recycled polyethylene blockouts Test installation before test MPT Vehicle/installation geometries for test MPT Vehicle before test MPT Vehicle properties for test MPT Sequential photographs for test MPT1 (overhead and frontal views) Sequential photographs for test MPT1 (rear view) After impact trajectory for test MPTl nstallation after test MPT Vehicle after test MPT Summary of results for test MPT Vehicle angular displacements for test MPT Vehicle longitudinal accelerometer trace for test MPT Vehicle lateral accelerometer traces for test MPT Vehicle vertical accelerometer trace for test MPT LST OF TABLES Table No. Page 1 Performance evaluation summary for test MPTl, NCHRP Report 350 test lv

7 . NTRODUCTON The Federal Highway Administration (FHW A) has formally adopted the new performance evaluation guidelines for highway features set forth in National Cooperative Highway Research Program (NCHRP) Report 350( 1 ) as a "Guide or Reference" document in Federal Register, Volume 58, Number 135, dated July 16, 1993, which added paragraph (a)(13) to 23 CFR, Part FHWA has also mandated that, starting in September 1998, only highway safety appurtenances that have successfully met the performance evaluation guidelines set forth in NCHRP Report 350 may be used on the National Highway System (NHS) for new installations. The most significant change made in new NCHRP Report 350 guidelines with regard to the evaluation of longitudinal barriers was the adoption of a 2000-kg pickup truck (2000P) as a design test vehicle. Since most existing longitudinal barriers were tested with a large passenger sedan according to the previous guidelines contained in NCHRP Report 230( 2 ), it was necessary to re-evaluate the performance of these barriers under the new guidelines. As part of this re-evaluation process, the Federal Highway Administration (FHWA) sponsored the crash testing of many commonly used guardrail systems< 3 >. This testing indicated that the widely used G4(1 S) system was not in compliance with the new guidelines. This system consists of a 12-ga. W-beam rail mounted on W150x13.5 steel posts at a height of 550 mm to the center of the rail. The posts are embedded 1100 mm in the ground and are spaced at 1905 mm. Steel W150x13.5 blockouts are used between the post and the rail element in the standard design. During impact, the 2000P test vehicle rolled 90 degrees onto its side on the traffic side of the barrier. A subsequent test of a modified G4(1 S) guardrail was successful. The modified system was identical in construction to the standard system with the exception of replacing the W150x13.5 steel blockout with a nominal 52 nun x 203 mm wood blockout. During this test, the 2000P test vehicle remained upright and stable, and the system was judged to have met all applicable evaluation criteria. This report presents the results of a crash test on a modified G4(1 S) steel post, W -beam guardrail system with recycled polyethylene blockouts. This system not only provides user agencies with another option for use with steel post guardrail, but also provides the additional environmental benefits associated with the use of recycled materials. The crash test performed was NCHRP Report 350 test designation 3-11, which involves a 2000-kg pickup truck (2000P) impacting the barrier at a nominal speed and angle of 100 km/h and 25 degrees, respectively. A description of the installation, results ofthe full-scale crash test, and evaluation ofthe impact performance are presented in the sections which follow. 1

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9 . STUDY APPROACH TEST ARTCLE A modified 04(1 S) W -beam guardrail system was constructed for evaluation of a recycled polyethylene offset block. The system consisted of7.6-m long, 12-gauge W-beam rail elements mounted on 1830-mm long Wl50x13.5 steel posts at a height of550 mm to the center of the rail. The steel posts were spaced 1905 mm on center and embedded 1100 mm using a drill and backfill procedure. A 2-ft auger was used to drill the holes. The holes were backfilled with a Type A crushed limestone base material having a maximum dry density of (129 lb/ft 3 ) and an optimum moisture content of9.0 percent. The backfill material was compacted in 152 mm layers using a pneumatic tamper driven by an air compressor. The in-place density of three test holes was measured using a nuclear density gauge. The in-place measurements indicated a moisture content ranging from 6.5 to 7.4 percent and a compaction of greater than 95 percent as recommended in NCHRP Report 350. Results of the soil tests performed in conjunction with this test are given in Appendix A. The W150x13.5 steel offset blocks used in a standard 04(18) guardrail system were replaced with 152 mm x 200 mm x 3 56 mm long molded recycled polyethylene blockouts. A cross section of the modified 04(1 S) W -beam guardrail system is shown in figure 1. A 1 02 mm wide by 6.4 mm deep channel is molded into one of the 152 mm faces of the blockout to accept the flange of the W150x13.5 steel post and prevent rotation of the blockout in field applications. A 19-mm diameter hole is drilled through the blockout and offset 44 mm from the edge of the blockout to permit attachment through the flange of the steel post. The rail, recycled polyethylene blockout, and post are connected using a single 16-mm diameter button head guardrail bolt with no washers under the head of the bolt. Details of the recycled polyethylene blockout are shown in figure 2. Various physical and mechanical properties of the recycled blockout material as reported by the manufacturer are included in Appendix B. The completed test installation consisted of a 30.5-m long section of the modified steel post W -beam guardrail with recycled polyethylene blockouts and a flared, 11.4-m long BCTtype terminal at each end, for a total installation length of 53.3 m. The overall layout of the test installation is shown in figure 3 and photographs of the completed installation are shown in figure 4. FULL-SCALE CRASH TESTNG mpact Conditions Recommended procedures for the safety performance evaluation of highway features are presented in NCHRP Report 350. The test matrix for a longitudinal barrier consists of two tests: 3

10 W 150x Steel Post W-Beom Roil Recycled Polyethylene Block PLAN W150x13.5 Steel Post Recycled Polyethylene Block 16 Diem. Button-Head Boll with Nut " :. " : " :: :: : ::!! 1100 "..._ ELEVATON Figure 1. Cross section of modified guardrail system. 4

11 1/2" radius, all exterior corners l 7 7 /8" '0"'' i i J 1~ 3 1/4" y 1 -c:::~ Plan 0 somet ric \ 3/ 4" dia hole T 7" /4':-.j 14 ~l 1 /4" _j L 7 7/8" Elevation Side View Figure 2. Details of recycled polyethylene offset block. 5

12 " f ~ ~ 30.5 m modified w-beom 11.4 m BCT guordroil w/polyethylene blackouts 11.4 m 6CT l'~l ~~ ~ ~ ~ ~ i ~ t ~ ~~ ~ ij[ '[ r~ ~ ~ ~ ~ ~ ~1 [ b"c=>. [. <:::>.,"'21 J Figure 3. Layout of the modified steel post w-beam guardrail with recycled polyethylene blockouts.

13 ( ~ Figure 4. Test installation before test MPT. 7

14 Test Designation This test involves an 820-kg passenger car impacting the barrier at a nominal speed of 1 00 km/h and a nominal angle of 20 degrees. The purpose of this test is to evaluate the overall performance of the barrier section with specific attention given to occupant risk. Test Designation This test involves a 2000-kg pickup truck impacting the barrier at a nominal speed of 100 km/h and a nominal angle of 25 degrees. This test is intended to evaluate the strength of the barrier section in containing and redirecting the test vehicle. This test also examines vehicle stability and geometric compatibility with the barrier. Because the strength and stiffness of the modified steel post barrier with recycled polyethylene blackouts is considered to be equivalent to the standard G4(1 S) guardrail system, the small car test (Test Designation 3-1 0) was considered to be unnecessary. This was based on the fact that the standard G4(1 S) guardrail was previously approved under NCHRP Report 230 which incorporated impact conditions essentially the same as those currently contained in NCHRP Report 350. Furthermore, the impact performance with the small car should be improved over that observed with the standard G4(1 S) guardrail due to the increased offset distance provided by the new recycled polyethylene blockout over the standard W150x13.5 steel block. This should reduce the interaction of the vehicle with the steel guardrail posts, thereby resulting in a smoother redirection of the vehicle. Based on this information, only one crash test (Test Designation 3-11) was conducted for purposes of evaluating the impact performance of the recycled polyethylene blockout. This test involves a 2000-kg pickup truck impacting at the critical impact point (CP) of the length of need section at a nominal speed and angle of 1 00 km/h and 25 degrees. n accordance with the procedures and charts set forth in NCHRP Report 350, the CP was determined to be 4.5 m upstream of a splice. NCHRP Report 350 Evaluation Criteria The crash test performed in this study was evaluated in accordance with the criteria presented in NCHRP Report 350. As stated in NCHRP Report 350, "Safety performance of a highway appurtenance cannot be measured directly but can be judged on the basis of three factors: structural adequacy, occupant risk, and vehicle trajectory after collision." Accordingly, the following safety evaluation criteria from table 5.1 ofnchrp Report 350 were used to evaluate the crash test reported herein: Structural Adequacy A. Test article should contain and redirect the vehicle; the vehicle should not penetrate, underride, or override the installation although controlled lateral deflection ofthe test article is acceptable. 8

15 Occupant Risk D. Detached elements, fragments or other debris from the test article should not penetrate or show potential for penetrating the occupant compartment, or present an undue hazard to other traffic, pedestrians, or personnel in a work zone. Deformation of, or intrusions into, the occupant compartment that could cause serious injuries should not be permitted. F. The vehicle should remain upright during and after collision although moderate roll, pitching and yawing are acceptable. Vehicle Trajectory K. After collision it is preferable that the vehicle's trajectory not intrude into adjacent traffic lanes. L. The occupant impact velocity in the longitudinal direction should not exceed 12m/sand the occupant ridedown acceleration in the longitudinal direction should not exceed 20 G's. M. The exit angle from the test article preferably should be less than 60 percent of the test impact angle, measured at time of vehicle loss of contact with the test device. CRASH TEST AND DATA ANALYSS PROCEDURES The crash test and data analysis procedures were in accordance with guidelines presented in NCHRP Report 350. Brief descriptions of these procedures are presented below. Electronic nstrumentation and Data Processing The test vehicle was instrumented with three solid-state angular rate transducers to measure roll, pitch and yaw rates; a triaxial accelerometer near the vehicle center-of-gravity to measure longitudinal, lateral, and vertical acceleration levels, and a back-up biaxial accelerometer in the rear of the vehicle to measure longitudinal and lateral acceleration levels. The accelerometers were strain gauge type with a linear millivolt output proportional to acceleration. The electronic signals from the accelerometers and transducers were transmitted to a base station by means of constant bandwidth FMJFM telemetry link for recording on magnetic tape and for display on a real-time strip chart. Calibration signals were recorded before and after the test, and an accurate time reference signal was simultaneously recorded with the data. Pressure 9

16 sensitive switches on the bumper of the impacting vehicle were actuated just prior to impact by wooden dowels to indicate the elapsed time over a known distance to provide a measurement of impact velocity. The initial contact also produced an "event" mark on the data record to establish the exact instant of contact with the installation. The multiplex of data channels, transmitted on one radio frequency, was received at the data acquisition station, and demultiplexed into separate tracks oflnter-range nstrumentation Group (.R..G.) tape recorders. After the test, the data were played back from the tape machines, filtered with ansae J211 filter, and digitized using a microcomputer, for analysis and evaluation of impact performance. The digitized data were then processed using two computer programs: DGTZE and PLOT ANGLE. Brief descriptions on the functions of these two computer programs are provided as follows. The DGTZE program uses digitized data from vehicle-mounted linear accelerometers to compute occupant/compartment impact velocities, time of occupant/compartment impact after vehicle impact, and the highest 1 O-ms average ridedown acceleration. The DGTZE program also calculates a vehicle impact velocity and the change in vehicle velocity at the end of a given impulse period. n addition, maximum average accelerations over 50-ms intervals in each of the three directions are computed. For reporting purposes, the data from the vehicle-mounted accelerometers were then filtered with a 60 Hz digital filter and acceleration versus time curves for the longitudinal, lateral, and vertical directions were plotted using a commercially available software package (QUATTRO PRO). The PLOT ANGLE program used the digitized data from the yaw, pitch, and roll rate transducers to compute angular displacement in degrees at s intervals and then instructs a plotter to draw a reproducible plot: yaw, pitch, and roll versus time. These displacements are in reference to the vehicle-fixed coordinate system with the initial position and orientation of the vehicle-fixed coordinate system being that which existed at initial impact. Anthropomorphic Dummy nstrumentation Use of a dummy in the 2000P test vehicle is optional according to NCHRP Report 350; therefore, no dummy was used in the test. Photographic nstrumentation and Data Processing Photographic coverage of the test included three high-speed cameras: one overhead with a field of view perpendicular to the ground and directly over the impact point; and one placed behind the installation at an angle; a third placed to have a field of view parallel to and aligned with the installation at the downstream end. A flash bulb activated by pressure sensitive tape switches was positioned on the impacting vehicle to indicate the instant of contact with the 10

17 installation and was visible from each camera. The films from these high-speed cameras were analyzed on a computer-linked Motion Analyzer to observe phenomena occurring during the collision and to obtain time-event, displacement and angular data. A Betacam, a VHS-format video camera and recorder, and still cameras were used to record and document conditions of the test vehicle and installation before and after the test. Test Vehicle Propulsion and Guidance The test vehicle was towed into the test installation using a steel cable guidance and reverse tow system. A steel cable for guiding the test vehicle was tensioned along the path, anchored at each end, and threaded through an attachment to the front wheel of the test vehicle. An additional steel cable was connected to the test vehicle, passed around a pulley near the impact point, through a pulley on the tow vehicle, and then anchored to the ground such that the tow vehicle moved away from the test site. A 2 to 1 speed ratio between the test and tow vehicle existed with this system. Just prior to impact with the installation, the test vehicle was released to be free-wheeling and unrestrained. The vehicle remained free-wheeling, i.e., no steering or braking inputs, until the vehicle cleared the immediate area of the test site, at which time brakes on the vehicle were activated to bring it to a safe and controlled stop. 11

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19 ll. CRASH TEST RESULTS TEST MPT1 (NCHRP Report 350 Test Designation 3-11) A 1992 Chevrolet 2500 pickup truck, shown in figures 5 and 6, was used for the crash test on the standard W-beam guardrail system on steel posts with plastic blockouts. Test inertia weight of the vehicle was 2000 kg, and its gross static weight was 2000 kg. The height to the lower edge of the vehicle bumper was 415 mm and it was 640 mm to the upper edge of the bumper. Additional dimensions and information on the vehicle are given in figure 7. The vehicle was directed into the installation using the cable reverse tow and guidance system, and was released to be free-wheeling and unrestrained just prior to impact. Test Description The vehicle, traveling at kmlh, impacted the modified steel post W-beam guardrail system with recycled polyethylene blockouts 800 mm upstream of post 9, or 4.5 m upstream of the splice at the one-third point of the installation, at degrees. Approximately s after impact, the left front comer of the vehicle bumper reached the first post after impact (i.e., post 9), and at s, the vehicle began to redirect. The front of the vehicle contacted post 10 at s, and post 11 at s. At s, the left front comer of the vehicle contacted post 12. The vehicle was traveling parallel with the guardrail at sat a speed of70.82 kmlh. At s, the left front comer of the vehicle contacted post 13, followed by contact with post 14 at s. The vehicle lost contact with thew-beam rail element near post 14 at s while traveling at a speed of kmlh and at an exit angle of degrees. mmediately upon loss of contact with the guardrail, the vehicle steered back toward the guardrail. A secondary impact with the guardrail occurred at s between posts 23 and 24. The vehicle subsequently came to rest against the guardrail 36 m downstream from the point of impact. Sequential photographs of the test period are shown in figures 8 and 9. Damage to Test nstallation Damage to the guardrail system is shown in figures 10 and 11. The buffer end of the BCT-type terminal was pulled away from post 1 and post 1 had moved 40 mm longitudinally toward the point of impact from the tensile forces generated in the rail and transmitted to the anchorage system. The recycled polyethylene blockout at post 7 was canted and the post had displaced 135 mm in the longitudinal direction. Post 8 deflected 90 mm laterally and 10 mm longitudinally, and the guardrail bolt was pulled through the rail element. Post 9 deflected 295 mm laterally and the bolt was partially pulled through the rail element. Post 10 was rotated approximately 90 degrees at the ground line and was deflected rearward 290 mm. Post 11 was rotated 180 degrees at the ground line and had a permanent deflection of250 mm. The recycled polyethylene blockouts at posts 10 and 11 became detached from the rail when the guardrail bolts pulled through the rail element and subsequently failed at the connection to the steel post. 13

20 Figure 5. Vehicle/installation geometries for test MPTl. 14

21 Figure 6. Vehicle before test MPTl. 15

22 DATE: _... ] _._ 1_-.1'-'3" ---"'- 9 -"' 6-- TEST NO. : MPT1 VN NO.: _1.~..,;G...,.C... G"-C<J. 2-"4LLK,_,O..uNL.U.. E..L1...,3""0""' 9'-"5L1L YEAR:,_ ] -""9_..9'""2 MAKE:,C...:h~..~..~<. e :J..vu ro..(jlj;;ew_ t MODEL: --"'2-'"' 5"-Q~OL.._.p_,jL.!.. LJ _ TRE NFLATON PRESSURE: ODOMETER: JJ...:4 :L6!oLL ,8""0' TRE SZE: LT R 1 6 MASS DSTRBUTON (kg) LF _5..l.,J RF _~5c4:t..:4 :t... LR 4.3.=t 4 RR_----!4"-'4""9"' DESCRBE ANY DAMAGE TO VEHCLE PROR TO TEST: n= - [ ~ ~~==~~~======~~~==~~~=== ==~---J-0~~~~ e Denotes accelerometer loc a tion. NOTES: 60 mm to the Left ENGNE TYPE:----'-'8---"c,_y.y.L --- ENGNE CD:,5... 7_.l TRANSMSSON TYPE: TEST N(l\TAl C.M, X AUTO _ MANUAL OPTONAL EQUPMENT: ~~ ~--~ 0 ~~----"'-!-"~ 1 ~ c -----~-- M, M, DUMMY DATA: TYPE: N /A MASS: N /A SEAT POSTON:_N"'+/..cA, GEOMETRY - (mm) A 18ZO E N 1610 B Z50 F _5_3_6_5, K c 3355 G Z5 p Z65 D 1815 H M R zoo s ZO u 4040 TEST MASS - (kg) CURB NERTAL M, ] ] 84 11lZ Mz MT 202Z 2000 GROSS STATC N/A ' N/A N/A ' Figure 7. Vehicle properties for test MPTl. 16

23 0.000 s s s s Figure 8. Sequential photographs for test MPT (overhead and frontal views). 17

24 0.362 s s s s Figure 8. Sequential photo graphs for test MPT 1 (overhead and frontal views) (continued). 18

25 0.000 s s s s s s s Figure 9. Sequential photographs for test MPT 1 (rear view). 19

26 Figure 10. After impact trajectory for test MPT1. 20

27 Figure 11. nstallation after test MPTl. 21

28 Before they failed, the bolts were partially pulled through the blockouts. At post 12, the rail element was detached and the guardrail bolt was deformed, but the plastic blockout remained attached. The post itself was rotated 180 degrees and was deflected laterally 300 mm. Post 13 was rotated 90 degrees and had a permanent deflection of290 mm. The recycled polyethylene blockout was still attached to the post, but was detached from the rail element. The blockout at post 14 was also detached from the rail and the post was deflected rearward 230 mm. All detached elements remained in close proximity to the test installation. Length of contact of the vehicle with thew -beam rail was 10.3 m. Maximum dynamic deflection during the test was 1.13 m and the maximum permanent deformation was 0.72 m. Vehicle Damage As shown in figure 12, the vehicle received relatively minimal damage. The left side tie rod ends, the left A-arms and spindle, and the left side frame were bent. Also damaged were the bumpers, the left side, and the left front tire and rim. Maximum deformation to the exterior of the vehicle was 490 mm near the top of the front bumper. There was no deformation or intrusion into the occupant compartment. Occupant Risk Values Data from the accelerometer located at the vehicle center-of-gravity were digitized for evaluation of occupant risk and were computed as follows. n the longitudinal direction, the occupant impact velocity was 6.74 m/s at s, the highest s occupant ridedown acceleration was g from to s, and the maximum s average acceleration was g between and s. n the lateral direction, the occupant impact velocity was m/s at s, the highest s occupant ridedown acceleration was 6.86 g from to s, and the maximum s average was 4.42 g between and s. These data and other pertinent information from the test are summarized in figure 13. Vehicle angular displacements are displayed in figure 14. Vehicular accelerations versus time traces are presented in figures 15 through

29 Figure 12. Vebicle after test l-mpt 1. 23

30 s s s t f') N General nformation ~ Test Agency Texas Transportation nstitute Test No MPT1 Date / 13/ 96 Test Article Type Name nstallation Length (m) Guardrail W -beam w/polyethylene blockouts 53.3 Size and/or dimension and material of key elements Soil Type and Condition.... Standard W-beam guardrail on steel posts with polyethylene blockouts Standard soil, dry Test Vehicle Type Production Designation P Model Chevrolet 2500 pickup Mass (kg) Curb Test nertial Dummy No dummy Gross Static mpact Conditions Speed (km/h) Angle (deg) Exit Conditions Speed (km/h) Angle (deg) Occupant Risk Values mpact Velocity (m/s) x-direction y-direction Ridedown Accelerations (g's) x-direction y-direction Max s Average (g 's) x-direction y-direction z-direction Test Article Deflections (m ) Dynamic Permanent Vehicle Damage Exteri or VDS CDC Maximum Exterior Vehicle Crush (mm)... nterior OCD Max. Occ. Compart. Deformation (mm) LFQ3 11FLEW3 490 Post-mpact Behavior (during 1.0 s after impact} Max. Roll Angle (deg} Max. Pitch Angle (deg} Max. Yaw Angle (deg) FSOOOOOOO Figure 13. Summary of results for test MPTl.

31 Crash Test MPTl Vehicle Mounted Rate Transducers 50 -c------~---c ~ ,------~~. t l ~ ~ ~ ~ , ~ ~ y , ~ ~ ~ ~ N t.h ~ Yaw Pitch -- Roll ] i J ~ ~ ~ ~ ' ~ ~, ~. ~, ~ ~~:"::' ;('-''--':C~' 0::_-/- ~J;~_:_::c::c- c~oe- 'c ~<::-1 t ~ ~--/-- ~ ~ ~ ~ Time After mpact (seconds) Axes are vehicle-fixed. Sequence for determining orientation is: 1. Yaw 2. Pitch 3. Roll Figure 14. Vehicle angular displacements for test MPT.

32 Crash Test MPTl Accelerometer at center-of-gravity 20 ~ Ul -bi) '-" ~... 0 ~... ) 10 l L - -l _ - - _ - - L - - _ - _ ~ : ~ l ' Test Article: Test Vehicle: Test nertial Weight: Gross Static Weight: Test Speed: Test Angle: Modified Steel Post W-Beam Guardrail with recycled polyethylene blackouts 1992 Chevrolet 2500 pickup (2000P) 2000 kg 2000 kg km/h degrees r J -) u ~ 0 N 0', -('j ~... '"d ;::l... +-' bi) ~ 0 ~ Time After mpact (seconds) , 60-Hz Filter - 50-ms Average Figure 15. Vehicle longitudinal accelerometer trace for test MPT.

33 ~ rn -OJ) "-" ~... 0 &J 1-; il)... il) (.) (.) ~ 1'-J ) C\:S 1-; il) &J...:l Crash Test MPTl Accelerometer at center-of-gravity L _l L -~ ', 1 Test Article: Test Vehicle: Test nertial Weight: Gross Static Weight: Test Speed: Test Angle: Modified Steel Post W-Beam Guardrail with recycled polyethylene blackouts 1992 Chevrolet 2500 pickup (2000P) 2000 kg 2000 kg km/h degrees L ~ f ~ ~ ~ i ~ , f t f ' Time After mpact (seconds) Hz Filter - 50-ms Average Figure 16. Vehicle lateral accelerometer trace for test MPTl.

34 , 20 -, ,- Crash Test MPTl Accelerometer at center of gravity N r--_ ell -bj) '-' :::::: 0... ~ ;...,!) -!) () () ~ -ro... ~!) > CX! () , _, ~ with recycled polyethylene blackouts Test Vehicle: 1992 Chevrolet 2500 pickup (2000P) 1 1 Test nertial Weight: 2ooo kg -15 ~ ~ ; ~ J Gross Static Weight: 2000 kg Test Speed: km/h 1-l Test Angle: degrees 1-20 ~ ~ Time After mpact (seconds) Hz Filter - 50-ms Average Figure 17. Vehicle vertical accelerometer trace for test MPTl.

35 V. SUMMARY OF FNDNGS AND CONCLUSONS SUMMARY OF FNDNGS The modified steel post W -beam guardrail system with recycled polyethylene blackouts is judged to have met the performance evaluation criteria ofnchrp Report 350. The recycled polyethylene blackouts maintained their structural integrity and successfully fulfilled their intended function of providing separation between the rail and posts. The guardrail system successfully contained and redirected the test vehicle through controlled lateral deflection. The vehicle remained upright and stable throughout the impact sequence and did not show potential for penetrating, underriding or overriding the installation. The detaehed elements from the installation did not penetrate nor show potential for penetrating the occupant compartment, nor did they present undue hazard to others in the area. There was no deformation or intrusion of the occupant compartment. The vehicle did not intrude into adjacent traffic lanes and it came to rest against the guardrail after a secondary impact with the system. Occupant risk factors were well within the recommended limits specified in NCHRP Report 350. Additionally, the exit angle at loss of contact with the guardrail was less than 60 percent of the impact angle. CONCLUSONS As shown in table 1, the modified steel post W-beam guardrail system with recycled polyethylene blackouts met all evaluation criteria set forth in NCHRP Report 350 for test designation The blackouts maintained their structural integrity during the impact event and demonstrated their crashworthiness in steel post guardrail systems. Based on the results of the crash test reported herein, the recycled polyethylene blackouts manufactured by Mondo Polymer Technologies, nc. are also considered to be a suitable replacement or alternative to the 152 mm x 203 mm x 356 mm long blackouts used in the G4(2W) wood post W-beam guardrail system. 29

36 Table 1. Performance evaluation summary for test MPT1, NCHRP Report 350 test w 0 Test Agency: Texas Transportation nstitute Test No.: MPT1 Test Date: 11113/96 NCHRP Report 350 Evaluation Criteria Test Results Assessment Structural Adequacy A. Test article should contain and redirect the vehicle; the vehicle The standard W-bearn guardrail system on should not penetrate, underride, or override the installation steel posts with plastic blackouts contained although controlled lateral deflection of the test article is and redirected the vehicle through controlled acceptable. lateral deflection; the vehicle did not penetrate, underride, or override the installation. Occupant Risk D. Detached elements, fragments or other debris from the test article Detached elements did not penetrate nor show should not penetrate or show potential for penetrating the potential for penetrating the occupant occupant compartment, or present an undue hazard to other traffic, compartment, or presenting undue hazard to pedestrians, or personnel in a work zone. Deformations of, or others in the area. There was no deformation intrusions into, the occupant compartment that could cause serious or intrusion of the occupant compartment. injuries should not be permitted. F. The vehicle should remain upright during and after collision The vehicle remained upright and stable both although moderate roll, pitching and yawing are acceptable. during and after the collision. Vehicle Trajectory K. After collision, it is preferable that the vehicle's trajectory not The vehicle came to rest against the test intrude into adjacent traffic lanes. installation and did not intrude into adjacent Pass* traffic lanes. L. The occupant impact velocity in the longitudinal direction should Longitudinal occupant impact velocity was not exceed 12 m/s and the occupant ridedown acceleration in the 6.74 m/s, and longitudinal occupant ridedown Pass longitudinal direction should not exceed 20 G's. acceleration was g's. M. The exit angle from the test article preferably should be less than Exit angle at loss of contact with the guardrail 60 percent of test impact angle, measured at time of vehicle loss was 13 AO degrees which is less than 60 Pass* of contact with test device. percent of the impact angle. * Cntena K and M are preferable, but not reqmred. Pass Pass Pass

37 APPENDX A SOL TESTNG 31

38 BUCHANAN/SOL MECHANCS, NC. Consulting Engineers Geotechnical + Materials + Civil Design + Consulting Bryan, Texas 206 North Sims, 77803/P.O. Box 672, 77806/(409) TO: Letter of Transmittal Mr Roger Bligh TEXAS TRANSPORTATON NSTTUTE CE/TT Building Room #801 Texas A&M University College Station Texas PROJECT: Full Scale Crash Test on G4-1S Barrier with Mondo Blackout B/SM Project No Enclosed please find the items indicated: TEM COPES PAGES DATED X N-PLACE DENSTY TEST RESULTS /06/96 N-PLACE DENSTY TEST LOCATON PLAN CONCRETE REPORT SUMMARY OF LABORATORY TEST DATA X OPTMUM MOSTURE/DENSTY RELATONSHP /06/96 SEVE ANALYSS FLEXBLE BASE MATERAL REPORT BORNG PLAN BORNG LOG(S) REMARKS: November 8,

39 BUCHANAN/SOL MECHANCS, NC. Consulting Engineers Bryan, Texas 206 North Sims, 77803/P.O. Box 672, 77806/(409) N-PLACE DENSTY TEST RESULTS CLENT: PROJECT: DATE 11/06/96 Hole No. 1 11/06/96 Hole No. 2 11/06/96 Hole No. 3 TEXAS TRANSPORTATON NSTTUTE Full Scale Crash Test on G4-1S Barrier with Mondo Blackout PO # MPT TEST LOCATON MOSTURE CONTENT (%) B/SM PROJECT NO.: DRY DENSTY PERCENT MATERAL ( PCF) COMPACTON TYPE A A A - OPTMUM COMPACTON EFFORT MOSTURE CONTENT AASHTO T % NOTE: 12" depth tested MAXMUM DRY DENSTY pcf MATERAL TYPE (A) Crushed limestone 33 TESTNG ENGNEER:

40 BUCHANAN/SOL MECHANCS, NC. Consulting Engineers 206 N. Sims 77803/P.O. Box /Bryan, Texas (409) OPTMUM MOSTURE/DENSTY RELATONSHP CLENT: TEXAS TRANSPORTATON NSTTUTE B/SM PROJECT NO.: PROJECT: Full Scale Crash Test on G4-1S Barrier with DATE: November 6, 1996 Mondo Blackout PO # MPT1. METHOD OF COMPACTON: AASHTO T 180, Method D MATERAL: Crushed limestone OPTMUM MOSTURE CONTENT: 9.0% MAX DRY DENSTY: pcf LL: PL: P: REMARKS: Sample delivered to and obtained by B/SM November 6, The 19.0 mm material was replaced. A mechanically operated sector face rammer was used. 135 ZERO Alljl VODS CURVE ASSUM~ S. G. = 2.75 i... ~ ;:l u D...:) ;:.::.-<;::::: <Zl >::: Q) Q c Q j. i ~--~--~--~--~--,_--~---r--~---r---.--~ Moisture Content,% Dry Weight 34 _~/j!_ ~ l}j lj j f' l_'. /l;fr(f/ lj. ;{j/d'~~ A~~ J..

41 APPENDX B PROPERTES OF RECYCLED POLYETHYLENE BLOCK OUT 35

42 ASTM D-792- Specific Gravity 09/09/1996 Formula A/(A+W-B) Molded Specimens Prepared A = Wt. of sample in air W = Wt.. of partially immersed wire + weight. B - Wt. of immersed sample and partially mmersed Wire. Specimen 1: A: A+W= A+W-B= w SP.GR B= Specimen 2: A= A+W: A+W-8= W: SP.GR.: Specimen 3: A= A+W= A+W-8= W= SP.GR.= : Avemge of 3 Tests Specimen molding, conditioning, prepamtion, and test procedures were conducted in llccorrhlllce to ASTM D-792. ASTM D Durometer Hardness Shore 'D' Standard Test Method for Rubber Property- Duromctcr Hardness 09/09/1996 Specimen 1: Specimen 2: Specimen 3: Specimen 4: Specimen 5: Average of 5 tests: 50.8 Specimen molding, conditioning, preparation, and test procedures were conducted in accordance to ASTM D ASTM D-747- Bending Modulus 09/10/1996 Apparent Dending Modulus of Plastics Dy Means of a Cantilever Deam Stiffness PS 39, , ) Specimen Average of 5 tests: 39,855.9 Specimen molding, conditioning, preparation, and test procedures were conducted in accordance to ASTM D

43 ASTM D Tensil Properties of Plastics Specimen Peak PS ? Break PS Ultimate Elongation % Modulus 50% Modulus 100% Modulus 200% /10/1996 Average Speed = 5 in/min. Strain Range 500% Stress Renge Coincidence point jews used. Specimen molding, conditioning, preparation, and!es( procedures were contludetl in accordance!o ASTM D-638. ASTM D Standard Test Method for Flexural! Properties Method 1: Specimen on two supports, & loaded by means of a loading nose at th ~ midway point of the psecimen beam. Procedure 'f.:. Specimen Flexural (PS) Yeild- Strength Average of 5 Tests: Tongent Mod. of Elasticity (PS) Average of 5 Tests: ::lpecirnen molding. conditioning. preparation. and test procedures were conducted in aecordance to A::TM D-7!.>0. 37

44 Compression Properties of Rigid Plastucs: 09/10/1996 ASTM D-695 Used as guidance. Loud slowly increased to 200 Lbs. crosshead speed of 0.5"/min. 1" Diameter by 112" thick, non-porous, molded specimens. Smface area of block=() 71\S sq. in. Compressive Deformation Compressive PS Specimen.D. (Cm.) (Cm.) (ln.) (ln.) L ---.U2.5. QJfr _QJ_Q L Q35 _Ml Q_U 1 D21 ~ _1W :L _llzb _ll.1l D.ll L :1 a.n _ill\.8. Average Qj1 QjQ _QJj ills _QJj 0.14 MonsMto T-1 0 lensometer set-up: 2200 Lb. compression load cell with fixtures installed. Crosshead speed= 0.05"/min.; thickness setting= 1; extension= 1 00; Coincidence= 05. Stress setting = 200, 'Y' axis n = 20 Lbs force; strain setting 0.5, 'X' axis n =0.05" dell. Tare first preload to 5 Lbs force. reset tare & standby. Specimen molding, conditioning, preparation, and test procedures were conducted in accordance to ASTM D-695. Only cemin section> of the [est procedure in D-695 could be used as a guide and followed. The actual test procedure could not be followed precisely due to U1e specimen size specified, and the limited load cell capacity. Therefore, these compressive lest results are for "in-house" use only, or submi[[ed with this umlen;[anding. 38

45 REFERENCES 1. H. E. Ross, Jr., D. L. Sicking, R. A. Zimmer, and J. D. Michie, "Recommended Procedures for the Safety Performance Evaluation of Highway Features," NCHRP Report 350, Transportation Research Board, Washington, D.C., J. D. Michie, "Recommended Procedures for the Safety Performance Evaluation of Highway Appurtenances," NCHRP Report 230, Transportation Research Board, Washington, D.C., K. K. Mak, R. P. Bligh, and W. L. Menges, "Crash Testing and Evaluation of Existing Guardrail Systems," Volume X of 14 volume draft final report, FHWA Contract No. DTFH61-89-C-00089, Federal Highway Administration, \Vashington, D. C., December,