Volumetrics Example
Properties:Mix Bulk Specific Gravity:2.329
Aggregate Bulk Specific Gravity:2.705
Aggregate Effective Specific Gravity:2.731
Asphalt Binder Specific Gravity:1.015
Asphalt Content:5.0% by mass
Find:Air void content
Voids in Mineral Aggregate (VMA)
Voids Filled with Asphalt (VFA)
Absorbed asphalt content
Effective asphalt content
Maximum theoretical specific gravity (Gmm)
Component Diagram
Volumetrics / Gmb = 2.329 / WeightAir
Asphalt
Gs = 1.015 / Pb = 5.0%
Absorbed Asphalt
Aggregate
Gsb = 2.705
Gse = 2.731 / 95%
Step 1 = Determine Density
D = Gbulk-mix x 1.000g/cc = 2.329 x 1.000g/cc = 2.329g/cc
Component Diagram – The sample is assumed to have:
a mass of 2.329 grams
occupy one cubic centimeter
Step 2 = Determine Mass
Mair = 0
Masphalt = (5/100) x 2.329g = 0.116g
Maggregate = (95/100) x 2.329g = 2.213g
Step 3 – Determine Volumetrics
Vtotal-asphalt = Masph / (Gasph x 1.000g/cc) = 0.116g/(1.015 x 1.000g/cc) = 0.114cc
Vbulk-aggr = Maggr / (Gbulk-aggr x 1.000g/cc) = 2.213g/(2.705 x 1.000g/cc) = 0.818cc
Veff-aggr = Maggr / (Geff-aggr x 1.000g/cc) = 2.213g/(2.731 x 1.000g/cc) = 0.810cc
Vabs-asph = Vbulk-aggr – Veff-aggr = 0.818cc – 0.810cc = 0.008cc
Veff-asph = Vtotal-asph – Vabs-asph = 0.114cc – 0.008cc = 0.106cc
Vair = Vtotal – (Vbulk-aggr + Veff-asph) = 1.000cc – (0.106cc + 0.818cc) = 0.076cc
VMA = Vair + Veff-asph = 0.076cc + 0.106cc = 0.182cc
Percent Volume Concentrations
Percent Vair = (0.076cc / 1.000cc) x 100% = 7.6%
Percent Vtotal-asphalt = (0.114cc / 1.000cc) x 100% = 11.4%
Percent Veff-asph = (0.106cc / 1.000cc) x 100% = 10.6%
Percent Vbulk-aggr = (0.818cc / 1.000cc) x 100% = 81.8%
Percent VMA = (0.182cc / 1.000cc) x 100% = 18.2%
or
Percent VMA = 100% - Percent volume of bulk aggregate = 100 – 81.8 = 18.2%
Step 4 – Calculate Effective Asphalt Content & Absorbed Asphalt Content
Meff-asph = Veff-asph x Gasph x 1.000g/cc = 0.106cc x 1.015cc x 1.000g/cc = 0.108g
Mabs-asph = Vabs-asph x Gasph x 1.000g/cc = 0.008cc x 1.015cc x 1.000g/cc = 0.008g
Effective AC = (Meff-asph / Mtotal) x 100% = (0.108g / 2.329g) x 100% = 4.6%
Absorbed AC = (Mabs-asph / Maggr) x 100% = (0.008g / 2.213g) x 100% = 0.4%
Step 5 – Calculate Voids Filled with Asphalt
Percent VFA = (Veff-asph / VMA) x 100% = (0.106cc / 0.182cc) x 100% = 58.2%
Step 6 – Calculate Maximum Theoretical Specific Gravity
Gmm =[(Masph + Maggr) / (Vbulk-aggr + Veff-asph)] / 1.000g/cc =
[(0.116g + 2.213g) / (0.106cc + 0.818cc)] / 1.000g/cc = 2.521
Answers:Air void content7.6%
Voids in Mineral Aggregate (VMA)18.2%
Voids Filled with Asphalt (VFA)58.2%
Absorbed asphalt content0.4%
Effective asphalt content4.6%
Maximum theoretical specific gravity (Gmm)2.521
Component Diagram
Compacted Specimen Data Analysis
Total Mass = 4783g / Correction Factor = 1.0199Gmm (measured) = 2.478
Number of
Gyrations / Height
(mm) / Volume
(cc) / Gmb
(est) / Gmb
(cor) / % Gmm
Ninit / 8 / 129.1 / 2281.4 / 2.097 / 2.138 / 86.29
50 / 118.9 / 2101.1 / 2.276 / 2.322 / 93.69
Ndes / 100 / 115.7 / 2044.6 / 2.339 / 2.386 / 96.28
150 / 114.0 / 2014.5 / 2.374 / 2.421 / 97.72
Nmax / 160 / 113.7 / 2009.2 / 2.380 / 2.428 / 97.97
Gmb (measured) = / - / - / 2.428 / - / -
where:V = volume of specimen in mold during compaction (cc)
d = diameter of mold (150mm)
h = height of specimen in mold during compaction (mm)
note – convert everything to cm
where:Gmb(est) = est. bulk specific gravity of specimen during compaction
V = volume of specimen in mold during compaction (cc)
W = mass of specimen (g)
where:C = correction factor
Gmb (measured) = measured bulk specific gravity after Nmax
Gmb(est) = estimated bulk specific gravity at Nmax
where:Gmb (corrected) = corrected bulk specific gravity of specimen
C = correction factor
Gmb(est) = estimated bulk specific gravity at any gyration, N
# of Gyrations / Criterion for %Gmm / Observed %GmmNinit (8) / <89.0 / 86.29
Ndes (100) / 96.0 / 96.28
Nmax (160) / <98.0 / 97.97
CEE 395 – Spring 2002Asphalt Mixture Volumetrics - 1 of 6