APPLYING WATER BLASTING TREATMENT POLICY AIMED AT REDUCING FIRST RAIN SKIDDING ACCIDENTS –THE ISRAELI EXPERIENCE Dr. Raphael Yaron – Aram Engineers, Israel Eng. Shimon Nesichi – Israel National Road Company Eng. Adrian Cotrus – Israel National Road Company Eng. Noam Weinstein – Israel National Road Company MAY 2011

Presentation Topics Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience The Israeli Policy Regarding FRSA Where to do? How to do? (contamination removal waterblasting technology) How to assure satisfactory job? Implementation Research project – Estimating Durability and Efficiency of the CRW Treatment policy Immediate /short term effect of treatment Current specs and QC procedures efficiency Durability (“service life”) of treatment Summary & Conclusions 2

BASICS OF FIRST RAIN SKIDDING ACCIDENTS (FRSA) – Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (1) BASICS OF FIRST RAIN SKIDDING ACCIDENTS (FRSA) – SKIDDING ACCIDENTS PHNOMENON WHICH OCCUR DURING/FOLLOWING THE FIRST RAIN WHICH FOLLOWS A LONG DRY SPELL FRSA ARE RELATED /CAUSED BY THE COMBINATION OF DUST AND OTHER POLLUTANTS ACCUMULATED DURING THE DRY SEASON, WITH RAINWATER, WHICH CREATES A MUDDY AND SLIPPERY FILM, REDUCING SKID RESISTANCE TO “BELOW NORMAL WINTER PERIOD CLEAN SURFACE CONDITIONS” 3

BASICS OF FIRST RAIN SKIDDING ACCIDENTS (FRSA) – Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (2) BASICS OF FIRST RAIN SKIDDING ACCIDENTS (FRSA) – THE LONGER THE DRY SPELL- THE MORE POLLUTED IS THE ROAD SURFACE- THE MORE DRAMATIC IS THE REDUCTION OF SKID RESISTANCE –THE HIGHER IS THE SKIDDING ACCIDENT PROBLEM VERY FEW STUDIES HAVE BEEN CONDUCTED IN SEVERAL COUNTRIES related to FRSA 4

Background- First Rain Skidding Accidents (FRSA) – Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (3) EFFECT OF POLLUTANTS ON SKID RESISTANCE ( Bennis & De Witt 2003) (ALSO Bird & Scott 1931, Wilson 2006) 5

Background- First Rain Skidding Accidents (FRSA) – Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (4) Eisenberg (2004) Study (1): Relationship between precipitation and traffic crashes in the US during the period 1975-2000 “the risk imposed by precipitation increases dramatically as the time since last precipitation increases …. 1cm of precipitation increases the fatal crash rate …. by about 3% if exactly 2 days have passed since the last precipitation and by about 9% if more than 20 days have passed” 6

Background- First Rain Skidding Accidents (FRSA) – Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (5) Eisenberg (2004) Study (2): “The lagged effects of precipitation across days may be explained by the clearing of oil that accumulates on roads during dry periods or by the conditioning of people to drive more safely in wet conditions.” 7

Background- First Rain Skidding Accidents (FRSA) – Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (6) ISRAEL CLIMATIC CONDITIONS ARE CHARACTERIZED BY A LONG DRY SEASON WITH ZERO PRECIPITATION, FOLLOWED BY ABOUT 4 MONTHS OF A RAINY SEASON THESE CONDITIONS may LEAD TO EXTREMELY LOW SR VALUES – about 20-60% lower than “normal clean surface rain conditions” - DUE TO DRY SUMMER POLLUTION 8

Change of SR During Dry Periods Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (7) Change of SR During Dry Periods 7 MU ROAR UNITS DROP - 18%

Change of SR During Dry Periods Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (8) Change of SR During Dry Periods 40 MU DYNATEST UNITS DROP - 57%

LIVNEH SKID RESISTANCE COMMITTEE (2007): Background- First Rain Skidding Accidents (FRSA) – International & Israeli Experience (9) LIVNEH SKID RESISTANCE COMMITTEE (2007): “ABOUT THREEFOLD CHANCE OF FRSA COPMPARED WITH “NORMAL” RAIN CONDITIONS SKIDDING ACCIDENTS” 11

The Israeli (INRC) Policy Regarding FRSA (1) Implementation of A SURFACING POLICY of using skid resistant /deep textured modern surface mixtures (mainly SMA) and reducing to minimum the use of dense graded mixtures

DGA (left) Vs. SMA (right)– Hw no. 2- 2006 DOLOMITE- DGA BASALT- SMA DGA (left) Vs. SMA (right)– Hw no. 2- 2006

The Israeli (INRC) Policy Regarding FRSA (2) Implementation of A MAINTENANCE POLICY of CONTAMINATION REMOVAL WATERBLASTING TREATMENT (CRW) at the end of the summer prior to the first rain Unique SR Policy Worldwide (?)

The Israeli (INRC) Policy Regarding FRSA (3) POLICY COMPONENTS (1) Determination of Road Sections to be treated HIGH FRICTION DEMAND SECTIONS POLLUTED SECTIONS (HISTORY) + SECTIONS DETECTED BY FRICTION SURVEYS BELOW INVESTIGATORY LEVEL (WINTER)

The Israeli (INRC) Policy Regarding FRSA (4) POLICY COMPONENTS (2) SPECIAL CONTAMINATION REMOVAL WATERBLASTING (CRW) TECHNOLOGY / EQUIPMENT: operated at relatively low water pressure (usually up to 500 atm) moving at a relatively high speed- daily production ABOUT 15,000 m2

The Israeli (INRC) Policy Regarding FRSA (5) CRW SYSTEM USED IN ISRAEL

The Israeli (INRC) Policy Regarding FRSA (6) POLICY COMPONENTS (3) QC+ ACCEPTANCE REQUIREMENTS FROM THE PROCESS (1): Control of driving speed and pressure Pendulum measurements after the CRW process by contractor’s technician

The Israeli (INRC) Policy Regarding FRSA (6) POLICY COMPONENTS (3) QC+ ACCEPTANCE REQUIREMENTS FROM THE PROCESS (2): Measurements are conducted :(1) on CRW treated surface (2) after scrubbing process performed with water and a hand brush with plastic bristles at the same point The results of the two measurements should not differ by more than 2-3 BPN (higher values indicate insufficient cleaning)

The Israeli (INRC) Policy Regarding FRSA (7) POLICY COMPONENTS (4) IMPLEMENTATION About 500000 m2 treated annually (about 1.5% of network) Timing – starting treatment by August (1-2 months before first rains are expected)

Are the current specs and QC procedures satisfactory? Research on the DURABILITY AND EFFICIENCY OF The Israeli FRSA Treatment Policy (1) Research Questions: What is the immediate/short term effect on SR of the treatment in actual projects? Are the current specs and QC procedures satisfactory? What is the durability (“service life”) of the treatment?

Research Program Conducted: Research on the DURABILITY AND EFFICIENCY OF The Israeli FRSA Treatment Policy (2) Research Program Conducted: Monitoring of SR evolution following CRW treatment until first rain occurs 5 representative CRW projects Use of various SR measurement systems (BP, TD, ROAR)

Research on the DURABILITY AND EFFICIENCY OF The Israeli FRSA Treatment Policy (3) Research Findings (1): TYPICAL SR EVOLUTION FOLLWING CRW TREATMENT About 1 month

EFFECT OF MANUAL SCRUBBING ON CRW TREATED SECTIONS Research on the DURABILITY AND EFFICIENCY OF The Israeli FRSA Treatment Policy (4) Research Findings (2): EFFECT OF MANUAL SCRUBBING ON CRW TREATED SECTIONS MANUAL SCRUBBING IMPROVED SR BY MORE THAN 3 UNITS! “AGGRESSIVE” QA IS NEEDED OVER THE CONTRACTOR’S QC

RELATIVE IMPROVEMENT OF BPN VALUES AS A RESULT OF CRW TREATMENT Research on the DURABILITY AND EFFICIENCY OF The Israeli FRSA Treatment Policy (5) Research Findings (3): RELATIVE IMPROVEMENT OF BPN VALUES AS A RESULT OF CRW TREATMENT IN RELATIVE TERMS – THE LOWER THE EXISTING BP VALUE BEFORE CRW – THE HIGHER THE BP IMPROVEMENT POTENTIAL (UPTO 40%) IN ABSOLUTE TERMS THE IMPROVEMENT IS IN THE RANGE OF 8-16 FOR MOST MIXTURES A DEDUCTION FROM 2- THE BETTER “BASIC” MIX YOU HAVE- THE LESS SENSITIVE IT IS TO DRY SPELL POLLUTION AND TO FRSA

Summary & Conclusions (1) FIRST RAIN SKIDDING ACCIDENTS (FRSA) IS A “NON CONVENTIONAL” SKIDDING PROBLEM CREATED BY LONG DRY SPELL TYPICAL IN MEDITERRENEAN CLIMATE THE FRSA PROBLEM IS ESPECIALLY PRONOUNCED IN ROAD SECTIONS THAT HAVE BASIC ("CLEAN SURFACE") LOW VALUES OF SKID RESISTANCE NON CONVENTIONAL PROBLEM CALLS FOR NON CONVENTIONAL SR MANAGEMENT POLICY WHICH RELIES MAINLY ON CONTAMINANT REMOVAL WATERBLASTING (CRW) TECHNOLOGY

Summary & Conclusions (2) UNDER ISRAELI CONDITIONS THE CRW TREATMENT IS EFFECTIVE FOR MORE THAN A MONTH IN ORDER TO MAXIMIZE THE EFFECTS OF CRW, QC AND QA PROCEDURES MUST BE CONDUCTED IN VERY STRICT MANNER. THE BPN TESTING, INCLUDING THE MANUAL SCRUBBING PROCEDURE, WAS FOUND TO BE A GOOD TESTING PROCEDURE FOR THE ABOVE.

THANK YOU… 28