The Use of Milled Bituminous Material in Capping Layer A Case Study

Transcription

1 The Use of Milled Bituminous Material in The Use of Milled Bituminous Material in Fung, Eduardo - COBA, S.A. Baptista, Teresa - ALBERTO COUTO ALVES, S.A. Quintão, António - COBA, S.A.

2 1 INTRODUCTION 2 METHODOLOGY 2.1 BASIC APPROACH 2.2 ALTERNATIVE PAVEMENT STRUCTURAL ANALYSIS 2.3 FWD TESTS RESULTS 3 PROPERTIES OF THE MILLED BITUMINOUS MATERIAL. COMPACTION PROCEDURE. 4 - FINAL CONSIDERATIONS

3 1 INTRODUCTION LARGE QUANTITIES OF MILLED BITUMINOUS MATERIAL (MBM) ARE GENERATED IN ROAD PAVEMENT MAINTENANCE AND REHABILITATION ACTIVITIES; A SIGNIFICANT PERCENTAGE IS TAKEN TO DEPOSIT WITH NEGATIVE IMPACTS (e.g. COST AND ENVIRONMENTAL) ; A PAVEMENT STUDY USING MILLED BITUMINOUS MATERIAL IN CAPPING LAYER WAS CARRIED OUT FOR THE DESIGN PAVEMENT STRUCTURE FOR ALTERNATIVE ROAD TO NR IN PORTUGAL

4 1 INTRODUCTION DESIGN FLEXIBLE PAVEMENT STRUCTURE (DP): AC WEARING COURSE 5 cm DENSE BITUMEN MACADAM BINDER COURSE 9 cm CRUSHED STONE BASE COURSE 15 cm CRUSHED STONE SUB-BASE COURSE 15 cm GRANULAR CAPPING LAYER 15 cm

5 1 INTRODUCTION PROPOSED ALTERNATIVE STRUCTURE (AP): AC WEARING COURSE 5 cm DENSE BITUMEN MACADAM BINDER COURSE 9 cm CRUSHED STONE BASE COURSE 20 cm MILLED BITUMINOUS CAPPING LAYER 25 cm

6 2.1 BASIC APPROACH a) AP BEARING CAPACITY EQUIVALENT TO DP CRITICAL STRAINS AP DP b) FIELD TESTS TO ASSESS OVERALL E MODULUS FOUNDATION PLATFORM c) MILLED BITUMINOUS MATERIAL COMPLY WITH NATIONAL LABORATORY SPECIFICATION E

7 2.2 ALTERNATIVE PAVEMENT STRUCTURAL ANALYSIS DESIGN PAVEMENT ANALYSIS Thickness E Modulus Poisson Tensile Compressive (cm) (MPa) Coef. Strain Strain AC Wearing Course ,35 DBM Binder Course ,35 1.9x10-4 (**) Foundation Platform Crushed Stone Base ,35 Crushed Stone Sub-base ,40 Granular Capping Layer x10-4 (***) 80 (*) 0,45 (*) Soil - (*) - Overall values below platform level (**) - Asphalt layer bottom interface (***) - Top of foundation platform

8 2.2 ALTERNATIVE PAVEMENT STRUCTURAL ANALYSIS ALTERNATIVE PAVEMENT ANALYSIS ThicknessE Modulus Poisson Tensile Compressive (cm) (MPa) Coef. Strain Strain AC Wearing Course ,35 Foundation Platform DBM Binder Course , x10-4 (**) Crushed Stone Base ,40 Milled Bituminous Material x10-4 (***) 120 (*) 0,45 (*) Soil - (*) - Overall values below platform level (**) - Asphalt layer bottom interface (***) - Top of foundation platform

9 2.3 FWD TESTS RESULTS E Modulus assigned to foundation platform according to the characteristic deflection values corresponding to 85 percentile (D 85% ) Loading Impact: 20kN Plate Diameter: 0,450m Tested Layer E (MPa) Capping layer D 85% (µm)

10 2.3 FWD TESTS RESULTS 2 alignments on test section: D 85% Alig 1= 277µm ; D 85% Alig 2 = 296µm

11 3 PROPERTIES OF THE MILLED BITUMINOUS MATERIAL

12 3 PROPERTIES OF THE MILLED BITUMINOUS MATERIAL Result Reference Value LNEC 474 Maximum Particle Size: 31,5 mm (Dmax) MAT1 Dmax 150 mm MAT2 Dmax 80 mm Maximum Fines Content: 1,9% (LNEC E 196) MAT1 10% MAT2 10% Shaliness: 0,02 / 100g MAT1 VBS < 0,20 g/100g (NF P ) MAT2 VBS < 0,10 g/100g

13 3 PROPERTIES OF THE MILLED BITUMINOUS MATERIAL Result Reference Value LNEC 474 Specification Resistance to Fragmentation: LA = 18,3% LA 45 (NP EN ) Resistance to Wear: MDE = 10,2% (NP EN ) MDE 45 Result Reference Value LNEC 474 Specification Sulphate Content (NP EN ) = 0,02% 0,70%

14 3 PROPERTIES OF THE MILLED BITUMINOUS MATERIAL FIELD COMPACTION: - NO TYPICAL COMPACTION CURVE; - REFERENCE DENSITY OBTAINED BY PROGRESSIVE NUMBER OF PASSAGES WITH INCREMENTS OF MOISTURE CONTENT; - MAX. DENSITY gr/cm 3 ; OPC 10%; RELATIVE COMPACTION: 97 TO 99%

15

16

17

18

19 4 - FINAL CONSIDERATIONS MILLED BITUMINOUS MATERIAL CAN BE USED WITH ADVANTAGE IN ROAD PAVEMENT CONSTRUCTION; FWD TESTS CONFIRMED GOOD PERFOMANCE AND BEARING CAPACITY OF THE MBM CAPPING LAYER; PROPERTIES OF MBM WERE PROPERLY CHARACTERIZED; COMPACTION PROCEDURE WAS DEFINED IN TEST SECTION; USE OF MBM IN ROAD CONSTRUCTION SHOULD BE ENCOURAGED AS A GOOD ENVIRONMENTAL CONTRIBUTION FOR SUSTAINABLE ROAD CONSTRUCTION.