ASTM E1337 Standard Test Method for Determining Longitudinal Peak Braking Coefficient (PBC) of Paved Surfaces Using Standard Reference Test Tire

ASTM E1337 Introduction

ASTM E1337 is used to measure the peak braking coefficient, which represents the maximum longitudinal force that the test surface can provide for a vertical load on a calibrated reference tire. One of the key points being considered regarding the safety of the vehicle is pavement-tire friction, particularly when braking on wet or dry surfaces. The procedure is carried out on asphalt (or concrete) paved roads, and using quantitative reportage to define road friction performance. It aids in assessing surface textures, wear, and pavement treatments at both research and applied engineering levels. 

ASTM E1337 Test Method

ASTM E1337 Equipment and Sample Preparation

ASTM E1337 Results and Interpretation

The result of the test is the peak braking coefficient (PBC), a dimensionless parameter representing the maximum ratio of braking force to normal load. The higher the value of PBC, the better the frictional performance of the surface. The results can be used to compare various pavement materials, examine surface treatments, or check the effects of wear and polishing on friction. 

ASTM E1337 Related Test Methods

ASTM E274 describes a method for determining pavement skid resistance using locked-wheel trailers, providing a practical approach to assessing pavement friction, particularly during highway safety analysis. ASTM E1551 has proposed a variable slip method in tire-pavement friction measurement that permits a holistic study of the slip of tire-pavement friction at various slip ratios.

ASTM E1337 Applications in Industry Use

Departments of transportation, pavement engineers, and researchers commonly rely on this method to assess and enhance road safety. It aids in the design and maintenance of high-friction surfaces at all locations, as well as in the main areas, such as intersections, curves, runways, and high-speed corridors. Accident investigation and forensic study also use it.

ASTM E1337 Materials Commonly Tested

The test is also normally used on asphalt concrete, grooved surfaces, textured or topped surfaces, as well as pavement surfaces that must have been treated with friction-enhancing products. Surfaces can be brand new or roadways in service in one or more environmental conditions.

ASTM E1337 Common Challenges and Troubleshooting

The primary challenges to be addressed are maintaining consistent tire condition, accurately regulating slip ratio, and considering environmental factors such as temperature, moisture, and soil pollution. Tire wear and surface variability can affect repeatability; therefore, calibration should be applied, along with test replications.

ASTM E1337 Safety and Best Practices

Tests should be performed under controlled conditions with no traffic on the road, in case it is undertaken on roads with any traffic. Discipline personnel are required to observe proper safety measures, wear high-visibility clothing, and ensure the proper calibration and secure placement of equipment. Wet testing should involve good control of drainage to prevent any runoff hazards.

Importance of ASTM E1337 Test Method

This method plays a pivotal role in the assessment of road safety, as it provides quantitative and reliable information regarding the performance of the pavement break. It assists in locating hazardous surfaces, informs pavement design, and informs transportation planning and maintenance decisions. The methodology will exhibit high stability to location variations, utilizing a standardized reference tire and a controlled evaluation procedure. This allows us to make national and international comparisons.