2. Concrete Pavements

3. The Right Tool for The Right Job.

4. Concrete Pavements The Right Tool for The Right Job.

5. Concrete Pavements: The Right Tool for the Right Job  Differences between Concrete and Asphalt Pavement  IH 610 – Four Decades of Superior Service  Forth Worth – Low Cost Concrete Pavements  Conclusions

6. Concrete Pavements: The Right Tool for the Right Job  Differences between Concrete and Asphalt Pavement  IH 610 – Four Decades of Superior Service  Forth Worth – Low Cost Concrete Pavements  Conclusions

7. The Differences Between Concrete and Asphalt Concrete Section Asphalt Section 6” Cement Stabilized Base Subgrade 1” Asphalt Bond Breaker 8”-15” Concrete 6” Lime Treated Subgrade 6” Base Subgrade 13” Asphalt Stabilized Base 4” Asphalt Surface Course 6” Lime Treated Subgrade

8. Concrete’s rigid structure spreads the load over a larger area and keeps pressures on the subgrade low. The Differences Between Concrete and Asphalt 18,000

9.  Better weight distribution means longer life for concrete pavements. The Differences Between Concrete and Asphalt

10.  Better weight distribution means longer life for concrete pavements.  Concrete is a long-term pavement with little maintenance; asphalt is a short-term pavement that requires periodic maintenance (mill and overlay). The Differences Between Concrete and Asphalt

11.  Concrete Pavement Advantages  Less rutting (less hydroplaning)  Less maintenance  Less rehabilitation  Better safety (Shorter stopping distance, better light reflection, fewer work zone accidents)  Concrete Pavement Disadvantage  Higher initial cost The Differences Between Concrete and Asphalt

12. More traffic, worse soil conditions are better suited to concrete pavements. The Differences Between Concrete and Asphalt Less traffic, better soil conditions are better suited to asphalt pavements. LOW TRAFFIC HIGH GOOD SOIL STIFFNESS POOR Conventional Wisdom

13. The Differences Between Concrete and Asphalt Concrete pavements are better suited for higher volumes and heavier loads. Asphalt pavements are better suited for lower volumes and lighter loads. Conventional Wisdom

14. Concrete Pavements: The Right Tool for the Right Job  Differences between Concrete and Asphalt Pavement  IH 610 – Four Decades of Superior Service  Forth Worth – Low Cost Concrete Pavements  Conclusions

15. How Concrete Pavements are Built 6” Cement Treated Base Reinforced Concrete Pavement Section 1” Asphalt Bond Breaker Subgrade 6” Lime Treated Subgrade 8”-15” Concrete

19. How Concrete Pavements are Built 6” Cement Treated Base Subgrade Reinforced Concrete Pavement Section 1” Asphalt Bond Breaker 8”-15” Concrete 6” Lime Treated Subgrade

22. How Concrete Pavements are Built 6” Cement Treated Base Subgrade Reinforced Concrete Pavement Section 1” Asphalt Bond Breaker 8”-15” Concrete 6” Lime Treated Subgrade

24. How Concrete Pavements are Built 6” Cement Treated Base Subgrade Reinforced Concrete Pavement Section 1” Asphalt Bond Breaker 8”-15” Concrete 6” Lime Treated Subgrade

29. Concrete Pavements: The Right Tool for the Right Job  Differences between Concrete and Asphalt Pavement  IH 610 – Four Decades of Superior Service  Forth Worth – Low Cost Concrete Pavements  Conclusions

30. Four Decades of Superior Service IH 610 West Loop in Houston

31.  Pavement Type: Continuously Reinforced Concrete Pavement (CRCP)  Project Length: 2.4 miles  Construction Date: 1963  Pavement Thickness: 8 inches  Pavement Design: 20 years, 7 million ESALs Four Decades of Superior Service

32. 0 10 20 30 40 50 19601970198019902000 Total ESALs (millions) Design: 7 million ESALs 1963-1996 Data IH 610 West Loop in Houston

33. 18,000 lbs per axle8,000 lbs Equivalent Single Axle Loads (ESALs)

34. Vehicle Auto, Van, Pickup Single Units 2-axle Panel Trucks Semi-tractor Trailer 3-axle Semi-tractor Trailer 4-axle Buses Semi-tractor Trailer 5-axle Equivalent Single Axle Loads (ESALs) Rigid ESALs0.0040.32 1.1 2.0 2.6 2.7 3.8

35. Equivalent Damage One 18-wheeler 9,600 cars Weight Matters! 80,000 lbs.2,000 lbs.

36. Maximum Truck Weights Weight Weight Limit (lbs) 58,420 73,280 80,000 19561975 Future? Current

37. Traffic Growth Traffic Traffic Time Past Traffic PredictionModels Current Traffic PredictionModels

38. Increased Pavement Damage PavementDamage Traffic Damage Due to Past Traffic Damage Due to Current Traffic (Increased Truck Weight) 4

39. Four Decades of Superior Service 0 10 20 30 40 50 19601970198019902000 Total ESALs (millions) Design: 7 million ESALs Actual: 38 million ESALs From actual traffic counts, more than 5 times the expected life! 1963-1996 Data IH 610 West Loop in Houston

40.  Dallas: IH 635 was built in mid-late 1960s, 8 inch CRCP, still in service today.  Dallas: IH 45 southbound was built in late 1960s, 15 miles of 8 inch CRCP, still in service today.  Dallas: North Central Expressway, built in late 1940s and early 1950s, in service until recent reconstruction in late 1990s. Long Term Concrete Pavements: Other Texas Examples

41. Concrete Pavements: The Right Tool for the Right Job  Differences between Concrete and Asphalt Pavement  IH 610 – Four Decades of Superior Service  Forth Worth – Low Cost Concrete Pavements  Conclusions

42. City of Fort Worth Street Paving Low Cost Concrete Pavement A Case Study

43. City of Fort Worth-1980  Failing infrastructure  Most of the streets were asphalt, Maintenance and reconstruction dollars shrinking  Vehicle weights and frequencies were climbing  Asphalt section (2” mat on 6” stone base) caused soaring maintenance costs

44. 1985 1990 CURRENT PROCURRENT PRO 1995 2000 2005 20 40 60 80 100

45. 1985199019952000 2005 20 40 80 60 100

46. City of Fort Worth  Streets had reached a point past economical maintenance and had to be rebuilt  Things began to change in the 1980s  First look on bids for Meadowbrook Road, project awarded to concrete despite 12% premium  Ederville Road alternate bid followed with a first– time economic analysis

47.   Economic analysis procedure that compares competing alternatives over their expected life by considering all significant initial and future costs (and benefits)   Discounts all future costs and benefits to present value Life Cycle Cost Analysis

48. Agency Costs:  Initial cost of pavement(s)  Maintenance and operation costs  Anticipated future rehabilitation costs  Engineering  Construction  Salvage (recycling value) Life Cycle Cost Analysis

49. Ederville Road  8000 vehicles per day, 2.5 % trucks (45 % trucks in the design lane)  CBR = 10 (“k” value 200 pci)  Traffic growth: 5% per year 7” AC Pavement 6” Lime Treated Subgrade Concrete Section (Est Life = 35 years) Asphalt Section (Est Life = 18.7 years) Low Cost Concrete Pavement A Case Study 6” Lime Treated Subgrade 6” PCC Pavement Designed using Asphalt Institute MS-1 Manual Designed using PCA Procedure (IS 184)

50. Life-Cycle Cost Analysis Concrete 510152025303540 Asphalt 510152025303540 Ederville Road Assumptions Chip or slurry seal 1.5 in. Overlay Chip Seal 1 in. OverlayAssumptions Crack Sealing

51. Ederville Road  Bids  Concrete: $1,178,996  Asphalt: $1,096,655  Difference:$ 82,341 First cost differential now just $82,341 (7%) as compared with Meadowbrook Road @ 14%  The economic analysis showed concrete cost $60,574 less for the city to own  Staff recommended award to concrete to Council  Project went Asphalt

52. Fort Worth Economic Analysis Assumptions  First Cost Analysis Based on 2,000 lf. of Street  15% Engineering Costs  Asphalt Pavement Design Life  Light Residential / Residential (28 ft. & 30 ft. Widths) – 24 Years  Collectors / Arterials (36 ft. & 40 ft. Widths) – 18 Years  Concrete Pavement Design Life  Light Residential / Residential (28 ft. & 30 ft. Widths) – 45 Years  Collectors / Arterials (36 ft. & 40 ft. Widths) – 35 Years

53. MAINTENANCE COSTS (all based on 1984 prices)  Concrete  Joint Sealing $1.00/SY  Asphalt  Seal Coat$0.57/SY  2 in. Overlay$3.00/SY  Crack Sealing$1.39/SY

54. Fort Worth Economic Analysis Concrete Asphalt City of Fort Worth 2 in. Overlay Light Residential and Residential Assumptions 28 ft. & 30 ft. Widths. Analysis Period = 45 yrs. Joint Sealing Reconstruct 5101520253035454051015202530354540 2 in. Overlay Crack Seal& Seal Coat Reconstruct (yr 48) Reconstruct2 in. Overlay Crack Seal& Seal Coat Crack Seal& Seal Coat Crack Seal& Seal Coat Crack Seal& Seal Coat

55. ASPHALT PAVEMENT COSTS (28 feet wide) YearOperationCost Cumulative Cost 0Construction$127,122$127,122 8 Crack Seal & Seal Coat 10,000137,122 14 2” Overlay 16,667153,789 20 Crack Seal & Seal Coat 11,500165,289 24Reconstruct127,122292,411 32 10,000302,411 38 2” Overlay 16,667319,078 44 Crack Seal & Seal Coat 11,500330,578 48Reconstruct127,122$457,700

56. CONCRETE PAVEMENT COSTS (28 feet wide) YearOperationCost Cumulative Cost 0Construction$153,378153,378 15 Joint Seal 5,555158,933 30 2” Overlay 16,667175,600 40 Crack Seal & Seal Coat 11,500187,100 45Reconstruct153,378$340,478

57. ASPHALT PAVEMENT COSTS (30 feet wide) YearOperationCost Cumulative Cost 0Construction$133,387$133,387 8 Crack Seal & Seal Coat 10,800144,187 14 2” Overlay 18,000162,187 20 Crack Seal & Seal Coat 12,420174,607 24Reconstruct133,387307,994 32 10,800318,794 38 2” Overlay 18,000336,794 44 Crack Seal & Seal Coat 12,420349,214 48Reconstruct133,387$482,601

58. CONCRETE PAVEMENT COSTS (30 feet wide) YearOperationCost Cumulative Cost 0Construction$155,275155,275 15 Joint Seal 6,000161,275 30 2” Overlay 18,000179,275 40 Crack Seal & Seal Coat 12,420191,695 45Reconstruct155,275$346,970

59. Life-Cycle Cost Analysis Concrete 510152025303540 Asphalt 510152025303540 Joint Sealing 2 in. Overlay City of Fort Worth Collectors and Arterials Assumptions 36 ft. & 40 ft. Widths. Analysis Period = 35 yrs. Crack Seal& Seal Coat Reconstruct 2 in. Overlay Crack Seal& Seal Coat Reconstruct2 in. Overlay Crack Seal& Seal Coat Reconstruct

60. ASPHALT PAVEMENT COSTS (36 feet wide) YearOperationCost Cumulative Cost 0Construction$157,764157,764 7 Crack Seal & Seal Coat 13,200170,964 12 2” Overlay 22,000192,964 18Reconstruct157,764350,728 25 Crack Seal & Seal Coat 13,200363,928 30 2” Overlay 22,800385,928 36Reconstruct157,764$543,692

61. CONCRETE PAVEMENT COSTS (36 feet wide) YearOperationCost Cumulative Cost 0Construction$186,330186,330 10 Joint Seal 7,333193,663 20 2” Overlay 22,000215,663 30 Crack Seal & Seal Coat 15,180230,843 35Reconstruct186,330$417,173

62. ASPHALT PAVEMENT COSTS (40 feet wide) YearOperationCost Cumulative Cost 0Construction$169,812169,812 7 Crack Seal & Seal Coat 14,800184,612 12 2” Overlay 24,667209,279 18Reconstruct169,812379,091 25 Crack Seal & Seal Coat 14,800393,891 30 2” Overlay 24,667418,558 36Reconstruct169,812$588,370

63. CONCRETE PAVEMENT COSTS (40 feet wide) YearOperationCost Cumulative Cost 0Construction$212,755212,755 10 Joint Seal 8,222237,422 20 2” Overlay 24,667245,644 30 Crack Seal & Seal Coat 17,020262,644 35Reconstruct212,755$475,419

64. Summary Pavement/ Street WidthFirst CostMaint. CostTotal Cost Asphalt 28’48 years$127,122$330,578$457,700 Concrete 28’$153,378 $187,100$340,478 Asphalt 30’48 years$133,387$349,214$482,601 Concrete 30’$155,275$190,695$346,970 Asphalt 36’36 years$157,764$385,928$543,692 Concrete 36’$186,330$230,843$417,173 Asphalt 40’36 years$169,812$418,558$588,370 Concrete 40’$212,755$262,664$475,419 + 26,146 -143,478 -117,222 + 21,888 -158,519 -135,631 + 28,566 -155,085 -126,519 + 42,943 -155,894 -112,961

65. Final Pavement Thickness Options (Adopted 1986) Concrete Asphalt Concrete Asphalt Residential 5-in. 6-in. 28’-30’ wide (now 6-in.) Collector 6-in. None Type A or B, 36’-40’ Arterials 7-in. None All pavements on 6” (concrete) or 8” (asphalt) cement or lime stabilized subgrade

66. How Did the Projects Change?

67. RESIDENTIAL STREET CONSTRUCTION PCC & HMAC 1984-1989 1984-85 228,700 SY 1985-86 234,500 SY 1986-87 371,200 SY 1987-88 218,600 SY 1988-89 129,667 SY

68. COLLECTOR STREET CONSTRUCTION PCC & HMAC 1983-1989 1983-84 181,800 SY 1986-87 43,484 SY 1984-85 170,311 SY 1987-88 97,831 SY 1985-86 329,000 SY 1988-89 127,037 SY

69. RESIDENTIAL & COLLECTOR STREETS 1980-1989 1980-81 375,300 SY 1984-85 399,000 SY 1981-82 247,600 SY 1985-86 563,400 SY 1982-83 320,000 SY 1986-87 469,000 SY 1983-84 522,000 SY 1987-88 262,000 SY 1988-89 247,704 SY

70. 1982-83 245,500 SY 1986-87 373,100 SY 1983-84 261,300 SY 1987-88 299,300 SY 1984-85 734,200 SY 1988-89 215,218 SY 1985-86 709,000 SY ARTERIAL STREET CONSTRUCTION 1983-1989

71. TOTAL CONSTRUCTION 1980-1989 1980-81 685,600 SY 1985-86 1,272,300 SY 1981-82 640,500 SY 1986-87 842,200 SY 1982-83 565,400 SY 1987-88 561,300 SY 1983-84 783,299 SY 1988-89 462,922 SY 1984-85 1,120600 SY

72. Although concrete pavements usually have high initial cost, they will have the lowest ultimate cost over the life of the pavement. Economic Analysis: Conclusions

73. Major Cities  Dallas  Started in the 1940s by DPW  Asphalt maintenance issues  Has retained concrete “mind set”  Other cities around Dallas followed the example  Concrete preferred because of poor, clay soils and performance

74. Major Cities  Houston  Concrete dates to 1920s & WPA Program  Concrete preferred because of poor soils and high water table  Asphalt did not perform in adverse soil and wet conditions

75. Concrete Pavements: The Right Tool for the Right Job  Differences between Concrete and Asphalt Pavement  IH 610 – Four Decades of Superior Service  Forth Worth – Low Cost Concrete Pavements  Conclusions

76. Concrete Pavements: The Right Tool for the Right Job  Concrete Pavement can distribute the load better than asphalt pavement.  Concrete Pavement is preferred when soils are poor and traffic volumes are high.  Concrete Pavement typically has higher initial cost and lower lifetime cost.

77. Concrete Pavements: The Right Tool for the Right Job Thank You!