Dr.Ambika Behl, Dr Siksha Kar, Sh. M N Nagabhushana, Prof. Satish Chandra, Sh. Manoj Shukla CSIR-Central Road Research Institute

Transcription

1 Dr.Ambika Behl, Dr Siksha Kar, Sh. M N Nagabhushana, Prof. Satish Chandra, Sh. Manoj Shukla CSIR-Central Road Research Institute 1

2 CO 2 -Emissions Emissions The construction of an average single lane-km of road produces enough pollution to equal up to 1,200 tons of CO 2 - roughly the same amount as the total annual emissions of 210 passenger cars. 2

3 Definition Recycling method where all of asphalt pavement section and a predetermined amount of underlying materials are treated to produce a stabilized base course. 3

4 Reduction in energy requirements to heat virgin aggregates & binders Hedge against rising bitumen prices & global uncertainty which can effect supply Reduces amount of virgin aggregates & bitumen which reduces material costs Benefits of RAP 4

5 CASE STUDY-NH2-Varanasi Aurangabad. Pavement has deteriorated severely, especially in the form of severe rutting coupled with cracks and deformation/ depression/ settlement 5

6 OPTIONS Conventional- Overlay Granular Sub Base (GSB)+ Granular Base (WMM) : 450mm Dense Bituminous Macadam (DBM): 185mm Bituminous Concrete (BC): 50mm Recycling Let s work Cold in situ recycling (CIR) using foamed bitumen approach was considered CIR is the processing and treatment with bituminous and/or chemical additives of existing HMA pavement without heating to produce a restored pavement layer. 6

7 7

8 8

9 9

10 10

11 Foam Bitumen Mix (FBM) or Bitumen Stabilized Material (BSM) Foamed bitumen Foamed bitumen - ~ 180 o C RAP + fresh aggregates - room temperature RAP Fresh aggregates Cement (1%) 11

12 Field Investigations Test pit observations, Coring of bituminous mixes, classified traffic volume survey, collection of milled material. 12

13 Milled material evaluated in CRRI laboratory. OPC cement grade 43 and stone dust was blended with 80 % of RAP material by weight of total mix to meet the gradation requirement of IRC 37:

14 Gradation & proportioning of Aggregates. 79% 0% 0% 0% 20% 1% Secified Limits Sieve size(mm) RAP A (40mm) B (20mm) C (10mm) D (stone dust) E (Ceme nt) Blend Lower Limit Uper Limit

15 COLD IN-SITU RECYCLING USING FOAM BITUMEN For RAP mix design I. Optimum foamed bitumen content- 2.25% II. Optimum moisture content 6%. III. Foaming characteristics were achieved at temperature of 180 C and foaming water content of 5%. IV. Foaming is done with VG-30 binder1% cement OPC 43 grade was added to improve the stability and better dispersion of foamed bitumen in fine particles of the mix 15

16 Foam Bitumen Treated-Marshall Samples. 16

17 Dry ITS Values Sample No Indirect Tensile Strength, kpa 2.0% Foamed Binder Content 2.25% Foamed Binder Content 3.0% Foamed Binder Content Sample No Wet ITS Values Indirect Tensile Strength, kpa 2.0% Foamed Binder Content 2.25% Foamed Binder Content 3.0% Foamed Binder Content

18 Resilient Modulus Values Resilient Modulus, MPa Sample 2.0% Foamed Binder 2.25% Foamed 3.0% Foamed No Content Binder Content Binder Content 25C 35C 25C 35C 25C 35C

19 Crust composition with 800 MPa E value for BSM layer-msa 185. Layer Specification Thickness( mm) 15 years Granular Sub Base (GSB)+ Granular Base (WMM) Foam Bitumen Stabilized Base (BSM) (recycled layer) Dense Bituminous 70 Macadam (DBM) Bituminous Concrete (BC) 50 19

20 CONSTRUCTION-CIPR Milling Surface after milling 20

21 CIPR Fresh dust spread over milled surface Spreading of cement 21

22 CIPR Cold in situ recycling Rolling operation 22

23 CIPR Recycled surface before overlay Recycled road after overlay 23

24 After 2 years 24

25 The Green Effect Conventional Overlay Granular Sub Base (GSB)+ Granular Base (WMM) : 450mm Dense Bituminous Macadam (DBM): 185mm Bituminous Concrete (BC): 50mm CIR Granular Sub Base (GSB)+ Granular Base (WMM) : 450mm Bitumen Stabilized material (BSM): 175mm Dense Bituminous Macadam (DBM): 70mm Bituminous Concrete (BC): 50mm By using foam stabilized technique, app 80% of recycled aggregate -reused and about 60% less bitumen used for construction of pavement. 25

26 Assessment of CO 2 Emission Emission per km per lane Present Pavement Design Conventional Design Consolidated results: tco 2 -eq Consolidated results: tco 2 -eq Construction materials: Recycled Aggregate 4.9 Cement 13.6 Bitumen 35.5 Bitumen 24.3 Aggregate 9.2 Aggregate 18.7 From mix preparation 20.2 From mix preparation 59.2 Total CO 2 equivalent emissions: 72.2 Total CO 2 equivalent emissions:

27 Aggregate and bitumen saving per km per lane have been found out about 833 and 31 tonne, respectively using the foam stabilized mix design in place of conventional design. Embodied energy of cement and recycled aggregate is also taken into consideration for GHG emission calculations. Approximately 40 tonne equivalent C0 2 is saved per km per lane. Hence, in total for 85 Km and 4 lanes construction project carbon emission reduction of about tonne equivalent C0 2 will be achieved. And 2,83,220 tonne of aggregate and 10,540 tonnes of bitumen will be saved. 27

28 Thank you Acknowledgements The authors are thankful to the team of M/s Soma Enterprises,M/s Wirtgen group for their support during the project and also during the formation of this paper. The research sponsoring organization and authors do not endorse any proprietary products or technologies mentioned in this paper. These appear herein only because they are considered essential to achieve the objective of this paper. 28