Lessons from Michigan's Oldest Concrete Pavement – Still Serving After 100 Years

1. Lessons from Michigan's Oldest Concrete Pavement – Still Serving After 100 Years Presented by: Thomas Van Dam, Ph.D., P.E. Program Director Materials and Sustainability providing engineering solutions to improve pavement performance

2. Organization • Introduction • Historical background • Laboratory analysis • Significance and conclusions

3. Introduction • Michigan’s oldest concrete pavement was constructed in Red Jacket (Calumet), Michigan in 1906 • Approximately four city blocks from this paving project are still in service as constructed • Although the technology used to construct this project have passed into history, the longevity of this concrete pavement still speaks to us today

7. Introduction (Continued) • A commemorative sign was erected in 1956 to designate the site • In 1957, a carefully worded sign was erected on Woodward Ave in Detroit stating “World’s First Mile of Concrete Highway” which up until this point was listed as Michigan’s oldest concrete pavement, being constructed in 1909 • Woodward Ave was replaced in 1922 as part of a pavement widening project

8. The 1956 unveiling of historical marker

10. Historical Background • At the dawn of the 20th century the village of Red Jacket, Michigan was thriving economically due to the booming copper mining industry • In 1906, a major public works project was undertaken to pave most of downtown Red Jacket • Both creosoted wood block pavement and granitoid brick block concrete pavement were used for the project

12. Historical Background (Cont.) • On January 26th, 1906, the Village Council of Red Jacket advertised for bids for the paving of streets • The materials under consideration included brick, macadam, creosoted wood block, and concrete (called granitoid) • Considerable public interest in the selection of the material • Brick was opposed by local businessmen

13. Historical Background (Cont.) • Granitoid was favored by the Village Council from the very beginning due to its low cost and durability • It was also thought to be the favorite of the business due to its durability • Granitoid pavements constructed in Chicago were still in good condition after 8 years of service • Two companies were hired for the paving • The R.S. Blome Co. for granitoid • A local company for creoted wood block

16. Historical Background (Cont.) • Local interest was very high • Job creation was of major importance • Aesthetics/environmental concerns expressed regarding trees • Performance of the pavement was also of great concern

22. Historical Background (Cont.) • Granitoid pavement design • 5” layer of sand, gravel, or crushed stone above the subgrade • 5-1/4” layer of concrete • 1 part portland cement, 3 parts sand, and 4 parts crushed stone, hand-mixed, mortar first with stone then being added, and then rammed into place • 1-3/4” mortar layer • 1 part portland cement and 1-1/2 part granite screenings or sharp clean sand applied to concrete layer before it sets • Carefully worked into a brick pattern

26. Laboratory Analysis • One core specimen obtained in 2006 • Two-layers very obvious • Lower concrete layer appears “poorly consolidated” • Typical of concrete from this time • 1956 PCA study determined compressive strength at 5,480 psi • Mortar layer appears dense

29. Laboratory Analysis (Cont.) • Concrete slabbed and polished • Thin sections were made and viewed using petrographic optical and scanning electron microscope

32. Plane Polarized Light Mortar Concrete Arrows denote large unhydrated cement grains

33. Crossed-polars Mortar Concrete Note: Birefringent materials appear bright, i.e. Ca(OH)2 as bright spots in mortar paste, and CaCO3 as tan patches in carbonated concrete paste.

34. Epifluorescence Mortar Concrete Note: Bright green areas denote porosity.

35. Laboratory Analysis (Cont.) • Concrete has considerable entrapped air and hydrated cement paste is fairly porous • Extensive carbonation • Mortar is extremely dense • Little carbonation or entrapped air • Large unhydrated cement grains present • Interiors are unhydrated, containing pristine cement phases

38. BSE images of unhydrated interiors of large cement grains

39. Calcium

40. Silicon

41. Calcium and Silicon • Alites look pink, belites look purple

42. Calcium and Silicon and Aluminum • Interstitial phases look green

43. Calcium and Silicon and Magnesium • Periclase (MgO) looks green

44. Significance and Conclusions • Those ignorant of their past are destined to repeat it • Similarly, there are some things that we have forgotten that remain of value • Durability and longevity are hallmarks of sustainability • The maintenance and rehabilitation costs of this pavement over the last 100 years are exactly $0 • Although the brick pattern was added to keep horses from slipping, it also provides an aesthetic quality while calming traffic in a residential neighborhood

45. Significance and Conclusions (Continued) • Why was this concrete so durable given it had no entrained air and it was in a severe F-T environment? • The surface mortar was extremely dense and impermeable • Low w/c, good densification, and wet cured • Similar capillary porosity to UHPC • High belite cement – similar to the use of SCMs • Mortar layer protected poorer quality lower concrete layer

46. Significance and Conclusions (Continued) • Two-layer system • Has come in and out of fashion over the decades • Currently making a comeback as a way to optimize material use given the position within the slab • Recycled materials, polishing susceptible materials in lower layers • Optimized surface for traffic (e.g. horses) • Worked amazingly well in this pavement

47. Significance and Conclusions (Continued) • Pavement type selection • The arguments are the same, just the materials have changed • Many factors are important, well beyond first cost • Sustainability is becoming more and more a factor, and parameters such as longevity, recycled material use (the aggregate was mine spoil), aesthetics, versatility, community acceptance, environmental concerns, etc. are becoming increasingly important

48. Acknowledgements • Village Council of Calumet for granting permission to core the historic pavement of Portland Street • Michigan Tech students Lawrence Mailloux and Kyle Ellis • And Dr. Karl Peterson from Michigan Tech