SCOPE

The percent of binder in hot mix asphalt mixtures can be determined by calculation using test results from IM 350 and IM 369.

REFERENCED DOCUMENTS:

IM 350, Determining Maximum Specific Gravity of Hot Mix Asphalt (HMA) Mixtures

IM 369, Determining Specific Gravity of Asphalt Binder

PROCEDURE

A. Determine the Effective Specific Gravity of the Aggregate, G_se.

*G_b at 77°F/77°F (25°C/25°C)

Throughout the first day of production, obtain at least three (3) samples of HMA, which will represent that day's production. Determine the maximum specific gravities on each of these samples according to IM 350 and determine the average. The binder contents may be obtained by measurements from tank stick or flow meter. The specific gravity of the binder may be obtained from the certification document or by test using IM 369.

B. After G_se has been determined it is used throughout the project to calculate the binder content of the mixture. If any proportions are changed G_se must be redetermined.

Determine the Binder Content for a given set of proportions, P_b.

REPORTING

The calculated asphalt content is reported to three (3) significant figures.

Example Calculations

Given:

P_b = 5.75

G_b = 1.021

G_mm = 2.451

Given:

G_se = 2.680

G_b = 1.021

G_mm = 2.451