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EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN. Kazuyuki KUBO Public Works Research Institute, Japan. Masaru TERADA Public Works Research Institute, Japan. Kazuhiro WATANABE Public Works Research Institute, Japan. EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN. Contents. - PowerPoint PPT Presentation
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EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
Kazuhiro WATANABEKazuhiro WATANABEPublic Works Research Institute, JapanPublic Works Research Institute, Japan
Kazuyuki KUBOKazuyuki KUBOPublic Works Research Institute, JapanPublic Works Research Institute, Japan
Masaru TERADAMasaru TERADAPublic Works Research Institute, JapanPublic Works Research Institute, Japan
Contents
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
1 INTRODUCTION
2 OBJECTIVE
3 SKID RESISTANCE
(1)Background(DF Tester)
(2)Relationship with braking force coefficient determined
using Friction Measurement Vehicle
(3)Investigation of the limits of using rubber pieces
(4)Investigation of the amount of water be sprayed
4 WATER PERMEABILITY
(1)Background
(2)Investigation on the inside diameter of the valve
(3)Investigation on the watertightness of water sealers
5 CONCLUSION
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
1.INTRODUCTION
1 Introduction The design guides for pavement were revised in 2001 in Japan
Specification-based StandardsSpecification-based Standards
Performance-based StandardsPerformance-based Standards
The road administrators specify the materials and structures of pavement. The constructors produced and applied asphalt mixes that satisfied the regulations in the manual.
The road administrators require performance for road surface through identifying the functions and needs of the surface of the road. The constructors can select and use materials that meet the required performances.
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
1.INTRODUCTION
Background of this revise …The functions required for pavement have
become increasingly diverse as society has developed.
The new rules have the freedom of designing pavement and selecting materials, respond to diverse needs, and encourage further technological innovation.
Therefore, various performance evaluation methods are being investigated in Japan.
2 Objective
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
2.OBJECTIVE
In this presentation, skid resistance and water permeability will be picked up and investigated toward appropriate evaluation.
Skid resistance : great relation to safety for driving a vehicle
the relationship with braking force coefficient determined Friction Measurement Vehicle and rolling skid number (RSN) determined by Dynamic Friction Tester (DF Tester)
the limits of using rubber pieces of DF Tester
the amount of water to be sprayed of DF Tester
To investigate
Water permeability : road noise reduction, traffic safety by preventing water from splashing during rainfall
the influence of the inside diameter of the valve in testers.
the watertightness of water sealers between road surface and testers
To investigate
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
3.SKID RESISTNACE
3 Skid resistance (1) Background (DF Tester)In Japan, Skid resistance is measured using…
Friction Measurement VehicleSkid Resistance Tester Based on Rotating Disc (DF Tester)The British Pendulum Tester
The second one which was developed in Japan is easy to measure, and has been standardized as an ASTM standard.
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
3.SKID RESISTNACE
Concept of DF Tester
Measurement of rolling skid number (RSN)
(2) Relationship with braking force coefficient determined using Friction Measurement Vehicle
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
3.SKID RESISTNACE
Braking force coefficient and RSN
In any type of DF Tester, They have good correlation.
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
3.SKID RESISTNACE
Braking force coefficient and RSN at each speed
Within the range of V=40 to 60km/h, there was a close correlation.
V=20km/h V=40km/h
V=60km/h V=80km/h
(3) Investigation of the limits of using rubber pieces
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
3.SKID RESISTNACE
Changes in rubber piece thickness
These figures showed that it is adequate to express the limit of using rubber pieces not by the number of measurements but by the degree of abrasion.
Changes in RSN during repeated measurements
So, we investigated the relationship between the rubber thickness and RSN.
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
3.SKID RESISTNACE
Rubber thickness and RSN (All kinds of pave.)
These figures showed that rubber pieces should be recommended to be exchanged when they have abraded by 0.5mm.
Rubber thickness and RSN (dens graded pave.)
(4) Investigation of the amount of water be sprayed
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
3.SKID RESISTNACE
Water runoff and RSN (dense graded pave.)
ASTM does not prescribe the difference in water head for spraying water during measurements. ( It states that the flow should be kept at 3.6L/min when the tank for supplying water is 0.6m above the tester.)We investigated the relationship between the amount of water be sprayed and RSN.
Not great influence on RSN from 2.2 to 4.0 L/min
Should be investigated in advance to give a flow of 3.6L/min that ASTM said
Valve
Water sealer
(unit : mm)
support
Doughnut-shaped weight
Valve
Water sealer
(unit : mm)
support
Doughnut-shaped weight
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
4.WATER PERMEABILITY
4 Water permeability (1) BackgroundIn Japan, porous asphalt pavement is increasingly used mainly on major roads to reduce traffic noise and ensure traffic safety by preventing water from splashing during rainfall.
The current evaluation method involves measuring the amount of penetrated water by using an in-situ permeability tester like right side figure.
This figure shows care must be taken on the inside diameter of the valves to be used (the inside diameter of the valves 8 mm or larger).
1,200
1,300
1,400
1,500
1,600
1,700
500 550 600 650 700水 頭 (mm)
浸透
水量 (m
l/15sec)
:φ 6.8mm:φ 8mm:φ 10mm
Water head (mm)
Wat
er
perm
eab
ility
(m
L/1
5se
c)
1,200
1,300
1,400
1,500
1,600
1,700
500 550 600 650 700水 頭 (mm)
浸透
水量 (m
l/15sec)
:φ 6.8mm:φ 8mm:φ 10mm
Water head (mm)
Wat
er
perm
eab
ility
(m
L/1
5se
c)
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
4.WATER PERMEABILITY
(2) Investigation on the inside diameter of the valveThe inside diameters of the valves of the testers sold in Japan were found to be 6.8, 8 and 10 mm.So we investigated the influence by these difference.
Valve
Water sealer
(unit : mm)
support
Doughnut-shaped weight
Valve
Water sealer
(unit : mm)
support
Doughnut-shaped weight
Valve
Water sealer
(unit : mm)
support
Doughnut-shaped weight
Valve
Water sealer
(unit : mm)
support
Doughnut-shaped weight
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
4.WATER PERMEABILITY
(3) Investigation on the watertightness of water sealersVarious kinds of water sealer are used for permeability testers.Because the current evaluation method directly measures the amount of water that flows into pavement, differences in the watertightness of water sealers are likely to strongly affect permeability measurements.So we investigated the influence depends on water sealers.
This figure shows highly watertight materials such as putty need to be used to seal in order to correctly evaluate.
Wat
er p
erm
eabi
lity
(mL/
15se
c)
Rubber ring Silicon mat Putty appliedRubber ring(standard) + silicon mat (no rubber ring)
Ways to cut off waterto cut off water
Wat
er p
erm
eabi
lity
(mL/
15se
c)
Rubber ring Silicon mat Putty appliedRubber ring(standard) + silicon mat (no rubber ring)
Ways to cut off waterto cut off water
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
5.CONCLUSION
5 ConclusionThere was a close correlation between RSN determined by DF Tester and the measurement by Friction Measurement Vehicle, especially within the range of V=40 to 60km/h.The rubber pieces which installed on a rotary disk of DF Tester should be exchanged before they abraded by 0.5mm.The amount of water to be sprayed from 2.2 to 4.0L/min in testing didn’t have great influence on RSN.
<SKID RESISTANCE>
<WATER PERMEABILITY>If the diameter of the valves is 6.8mm that is smaller than the inside diameter of the connecting pipes (=8.0mm), it has great possibility to evaluate performance of water permeability unfairly.Highly watertight materials need to be used between road surface and tester in order to correctly evaluate the seepage of rainwater into pavement.
EVALUATION METHODS OF ROAD SURFACE PERFORMANCE IN JAPAN
5.CONCLUSION
We will continue to study methods of evaluating various performance indices, aiming to establish methods that can correctly assess the performance requirements for pavement, encourage further innovations of pavement-related technologies, and improve the effects and efficiency of paving works.
Thank you for your kind attention.