土木工程道橋方向外文翻譯--夾層石路面的長期性能研究（英文）

1、Long-Term Performance of Stone Interlayer PavementHani Titi, P.E.1; Masood Rasoulian, P.E.2; Mark Martinez3; Byron Becnel, P.E.4; and Gary Keel5Abstract: This paper presents an evaluation of long-term performance of an a

2、lternative flexible pavement design referred to here as stone interlayer pavement. This pavement design was introduced to reduce/defer reflective cracking experienced with soil-cement bases. The stone interlayer pavement

3、 consisted of a crushed limestone base on top of a cement-stabilized base. The performance of the stone interlayer pavement was compared to that of the conventional pavement design with a cement-stabilized base. The ston

4、e interlayer and conventional pavements were constructed on State Highway LA-97 near Jennings, Louisiana. Both pavements were monitored for 10.2 years after construction. During the evaluation period, pavement distress s

5、urveys, testing of roughness and permanent deformation, and evaluation of pavement structural capacity using dynamic nondestructive testing were conducted. Additionally, as a part of the Louisiana Transportation Research

6、 Center accelerated pavement testing research program, both pavement designs were tested to failure under the Accelerated Loading Facility in Port Allen, Louisiana. The results of this investigation showed a superior per

7、formance of the stone interlayer pavement over the conventional soil cement pavement as tested in the field as well as under accelerated loading.DOI: 10.1061/?ASCE?0733-947X?2003?129:2?118?CE Database keywords: Flexible

8、pavements; Stones; Pavement design; Performance evaluation.IntroductionSoft and saturated subgrade soils are a common occurrence in Louisiana, especially in the southern part of the state. Such sub- grade soils are not c

9、ompetent to support pavements and their traffic loading. To overcome this problem, the Louisiana Depart- ment of Transportation and Development ?DOTD? has adopted a conventional pavement design method for flexible paveme

10、nts on state highways other than the interstate system. The design con- sists of lime treatment of subgrade soil ?subbase layer?, in-place cement stabilization of soil ?soil-cement base layer?, and a hot mix asphalt conc

11、rete ?HMAC? surface layer. This pavement de- sign method, with a strong soil-cement base, has the advantage of producing pavements that are structurally capable of supporting traffic loading under weak subgrade support.

12、In addition, the con- struction of pavements with soil-cement base layers is quick and cost effective. While the use of soil-cement base layers effectively improves the structural capacity of flexible pavements, it is th

13、e major cause of reflective cracking, which accelerates pavement deterioration and decreases pavement life.Researchers at the Louisiana Transportation Research Center ?LTRC? have focused their effort on innovative altern

14、ative meth- odologies to reduce reflective cracking and improve the long-term performance of flexible pavements in Louisiana. Among these methods is the use of granular materials ?such as crushed lime- stone? between the

15、 soil-cement base and the HMAC surface layer. This pavement type is denoted herein as the stone interlayer pave- ment. This paper describes a research effort conducted to evaluate the long-term performance of stone inter

16、layer pavement design and to assess the capability of the stone interlayer to reduce re- flective cracking in flexible pavements. Two flexible pavement sections were designed and constructed on State Highway LA-97 near J

17、ennings, Louisiana, in 1991. The first section consisted of conventional pavement design ?soil-cement base?, and the second section consisted of stone interlayer pavement design ?crushed limestone over soil-cement base?.

18、 The latter design is also re- ferred to as the inverted pavement design. The performance of the two pavements was monitored over a period of 10.2 years. Pave- ment distress surveys, evaluation of structural capacity of

19、the pavements, measurement of permanent deformation, and evalua- tion of pavement roughness and serviceability were conducted. In addition, the conventional and the alternative stone interlayer pavements were tested unde

20、r Accelerated Loading Facility ?ALF? at the Pavement Research Facility ?PRF? site in Port Allen, Loui- siana.BackgroundSoil-cement has long been used as engineered material in various applications including base layers i

21、n pavements with weak sub- grade soil. In addition, the use of soil-cement is cost effective in areas lacking aggregate resources. These conditions make south- ern Louisiana a perfect candidate for pavements with soil-ce

22、ment bases. Indeed, Louisiana has thousands of highway miles with soil-cement bases, some of which have been in service for more than 40 years. The use of soil-cement base course layers effec- tively improved the structu

23、ral capacity of pavements built on1Assistant Professor, Dept. of Civil Engineering and Mechanics, Univ. of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, WI 53201. 2Pavement Systems Specialist, Louisiana Transportation Re

24、search Center, 4101 Gourrier Ave., Baton Rouge, LA 70808. 3Pavement Research Engineer in Training, Louisiana Transportation Research Center, 4101 Gourrier Ave., Baton Rouge, LA 70808. 4Traffic Operations Engineer, Louisi

25、ana Dept. of Transportation and Development, P.O. Box 831, Baton Rouge, LA 70821. 5Engineering Technician, Louisiana Transportation Research Center, 4101 Gourrier Ave., Baton Rouge, LA 70808. Note. Discussion open until

26、August 1, 2003. Separate discussions must be submitted for individual papers. To extend the closing date by one month, a written request must be filed with the ASCE Managing Editor. The manuscript for this paper was subm

27、itted for review and pos- sible publication on December 3, 2001; approved on April 9, 2002. This paper is part of the Journal of Transportation Engineering, Vol. 129, No. 2, March 1, 2003. ©ASCE, ISSN 0733-947X/2003

28、/2- 118–126/$18.00.118 / JOURNAL OF TRANSPORTATION ENGINEERING © ASCE / MARCH/APRIL 2003addition, pavement sections were surveyed for raveling, shoving, and potholes. The severity level and patterns for cracks and o

29、ther distresses were determined according to the Distress Identification Manual for the Long-Term Pavement Performance Project ?SHRP 1993?. The pavement surface cracking surveys were conducted by mapping the longitudinal

30、 and transverse cracks on a paper. The distance from the beginning to the end of the crack was measured to determine the length of the crack.Nondestructive Evaluation of Pavement Structure As presented in Table 1, nondes

31、tructive pavement testing ?NDT? and evaluation of the test sections was conducted six times over the past 10.2 years. The NDT consisted of measurements of pave- ment deflection due to induced dynamic load using the Dynam

32、ic Deflection Determination System ?Dynaflect?. This system ?Fig. 4? is a nondestructive testing device that induces dynamic load on the pavement surface and measures the corresponding deforma- tion at different location

33、s. The maximum dynamic load, about 4.448 kN ?1,000 lb?, is induced due to countereccentric rotation of two masses at frequency of 8 Hz. The load is transmitted to the pavement through two steel wheels. The deformation is

34、 recorded by a set of five geophones installed on a beam and spaced at 305 mm ?12 in.?, with the first geophone placed between the two steel wheels. Kinchen and Temple ?1980? developed a mechanistic approachfor design of

35、 HMAC overlays based on deflection analysis. The methodology was proposed and verified based on comprehensive evaluation of the structural capacity of Louisiana pavements using the Dynaflect system. For more than 20 year

36、s, DOTD has been using this methodology for pavement evaluation and design. This method was used in the current study to evaluate the struc- tural capacity of the investigated pavements. A series of nondestructive testin

37、g was conducted during the different stages of the pavement construction. This was to evalu- ate the structural capacity of the individual pavement layers. The first set of nondestructive tests was conducted on the 305 m

38、m ?12 in.? lime-stabilized subbase for both test sections 1 and 2. Then the second set of testing was conducted after construction of 216 mm ?8.5 in.? soil-cement for test section 1 and 152 mm ?6 in.? soil cement for tes

39、t section 2. The third set was conducted only on test section 2 after the construction of the 102 mm ?4 in.? crushed limestone interlayer. The final set was conducted after construc- tion of the 89 mm ?3.5 in.? HMAC surf

40、ace layer. Tests were conducted on each section on 30 m ?100 ft? intervals.Evaluation of Pavement Roughness and Deformation Field tests were conducted to determine the ride quality and per- manent deformation ?rutting? o

41、f the investigated pavements. As presented in Table 1, field testing was conducted seven times during the last 10.2 years. From 1991 to 1995, the Mays Ride Meter ?MRM? was used to evaluate pavement roughness and the AASH

42、TO A-frame was used to measure pavement rutting. After 1995, the high-speed road profiler was used to evaluate pavement roughness and rutting. A description of the test equipment is given below.Mays Ride Meter ?MRM… The

43、MRM is equipment that measures road roughness consisting of a recorder, a photoelectric transmitter, and a special odometer. It is designed to operate in a vehicle with a traveling speed of 80 km/h ?50 mi/h?. MRM records

44、 travel distance from the actual road profile on continuous feed chart paper. Based on the relative movement of the car axle with respect to the vehicle body, the photocell transmitter converts the accepted light rays in

45、to electri- cal impulses that are converted into profile on the chart. Special charts are developed for interpreting road roughness using MRM test results. The MRM test results are expressed in terms of the Present Servi

46、ceability Index ?PSI?. Field testing using the MRM was conducted five times on the entire test section to ensure repeatability of test results. The MRM test results for the test sections were expressed in terms of PSI an

47、d then were converted into the International Roughness Index ?IRI? using the correlation established by Sayers et al. ?1986?.High-Speed Road Profiler The high-speed road profiler is a vehicle equipped with three laser se

48、nsors for height measurements, one sensor to measure travel distance, and two accelerometers to account for vehicle vibra- tions. The accelerometers allow the system to function indepen- dently of the vehicle characteris

49、tics and travel speed. The system is capable of collecting road profile data at a minimum distance interval of 76.2 mm ?3.0 in?. The LTRC high-speed road profiler was used to collect pave- ment surface data for evaluatio

50、n of roughness and rutting. Longi- tudinal profiles of the test sections were measured by conducting 3–5 runs on the entire test section to ensure repeatability of the test results. The profile of each wheel path was obt

51、ained, and the pavement roughness was determined in terms of IRI. The averageFig. 2. Location of project on State Highway LA-97 near Jennings, Louisiana120 / JOURNAL OF TRANSPORTATION ENGINEERING © ASCE / MARCH/APRI