Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
Transportation Short CourseOctober 10, 2017
USE OF REJUVENATORS (RECYCLING AGENTS)
WITH RECYCLED MATERIALS
MOTIVATION
• Reclaimed Asphalt Pavement (RAP)
• Recycled Asphalt Shingles (RAS)
• Workability
• Compaction
• Performance(cracking, raveling)
College Station, TX Transportation Short Course October 10, 2017
HOW DO WE EXPRESS RAP AND RAS CONTENT?
• Traditionally, by % of total mix (10% RAP & 5% RAS)
• Recently, Recycled Binder Ratio or RBR (decimal)
𝑅𝐵𝑅 = 𝑅𝐴𝑃𝐵𝑅 + 𝑅𝐴𝑆𝐵𝑅 = 𝑃𝑏𝑅𝐴𝑃 × 𝑃𝑅𝐴𝑃
𝑃𝑏𝑡𝑜𝑡𝑎𝑙+
𝑃𝑏𝑅𝐴𝑆 × 𝑃𝑅𝐴𝑆𝑃𝑏𝑡𝑜𝑡𝑎𝑙
https://eng.auburn.edu/research/centers/ncat/info-pubs/newsletters/atnfall2014.pdf
College Station, TX Transportation Short Course October 10, 2017
TxDOT ITEMS 340, 341, 344
RECYCLED BINDER RATIO (RBR)
• Advantages:
– RAPB & RASBR
– Weighted average of multiple components
• Disadvantages:
– Assumes 100% blending
Proposed shorthand notation
A/B|D/E
– A = RAP % of total mix
– B = RAS % of total mix
– C = RAPBR (decimal)
– D = RASBR (decimal)
College Station, TX Transportation Short Course October 10, 2017
HOW CAN MORE RAP AND RAS BE USED IN SURFACE MIXTURES?
RAP
RAS
Rejuvenated
Blend
Rejuvenated
Mixture
Recycling
Agents
Virgin
Binder
Virgin
Aggregates
College Station, TX Transportation Short Course October 10, 2017
WHAT ARE RECYCLING AGENTS?
Chemical products added to recycled asphalt mixtures
– To reduce mixture stiffness(asphaltene to maltene ratio)
– To improve the low-temperature and high-temperature PG
– Other benefits: better workability, better compaction, etc.
College Station, TX Transportation Short Course October 10, 2017
WHAT TYPES OF RECYCLING AGENTS ARE AVAILABLE?
College Station, TX Transportation Short Course October 10, 2017
HOW TO SELECT A RECYCLING AGENT?
Chemistry (FT-IR) Rheology (DSR)
0
10
20
30
40
50
60
T1 T2 A1 V2 V1 B
S│
DA
rea│
(a.
u.)
RTFO PAV 20 PAV 40
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
T1 A1 V2 B
h*
at1
5ᵒC
an
d 1
0 r
ad/s
(Pa.
s)
Original RTFO PAV 20 PAV 40
RA with smallest D FT-IR registered minimal D in rheologyT1 w/ greatest D in rheology & among highest D FT-IR
College Station, TX Transportation Short Course October 10, 2017
HOW TO SELECT A RECYCLING AGENT?
RA with smallest D FT-IR registered minimal D in rheologyT1 w/ greatest D in rheology & among highest D FT-IR
College Station, TX Transportation Short Course October 10, 2017
HOW MUCH RECYCLING AGENT SHOULD I ADD TO THE MIXTURE?
• High-Temp PG (DSR)
– Unaged
– RTFO aged
• Low-Temp PG (BBR)
20-hour PAV aged
𝚫𝑻𝒄 = (𝑻𝑺 − 𝑻𝒎)
College Station, TX Transportation Short Course October 10, 2017
RECYCLING AGENT DOSAGE SELECTIONDETAILED METHOD
y = -1.8x + 81.8
y = -1.7x + 85.1
0
10
20
30
40
50
60
70
80
90
0 2 4 6 8 10 12
Hig
h T
emp
. P
G G
rad
e (
C)
Dosage (%)
0.3 RBR (PG 64-22 | 0.1 TxRAP | 0.2 TxMWAS | T1)
Original G*/sin(d) RTFO G*/sin(d)
y = -1.8x + 81.8
y = -1.7x + 85.1
y = -1.3x - 16.0
y = -0.7x - 28.5
-40
-35
-30
-25
-20
-15
-10
-5
0
0
10
20
30
40
50
60
70
80
90
0 2 4 6 8 10 12
Lo
w T
emp
. P
G G
ra
de ( C
)
Hig
h T
emp
. P
G G
rad
e (
C)
Dosage (%)
0.3 RBR (PG 64-22 | 0.1 TxRAP | 0.2 TxMWAS | T1)
Original G*/sin(d) RTFO G*/sin(d) PAV m-controlled PAV S-controlled
y = -1.8x + 81.8
y = -1.7x + 85.1
y = -1.3x - 16.0
y = -0.7x - 28.5
-40
-35
-30
-25
-20
-15
-10
-5
0
0
10
20
30
40
50
60
70
80
90
0 2 4 6 8 10 12
Lo
w T
emp
. P
G G
rad
e (
C)
Hig
h T
emp
. P
G G
rad
e (
C)
Dosage (%)
0.28 RBR (Tx PG 64-22 | 0.1 TxRAP | 0.18 TxMWAS | T)
Original G*/sin(d) RTFO G*/sin(d) PAV m-controlled PAV S-controlled
A (6.0,70)
Target Grade: 70-22
y = -1.8x + 81.8
y = -1.7x + 85.1
y = -1.3x - 16.0
y = -0.7x - 28.5
-40
-35
-30
-25
-20
-15
-10
-5
0
0
10
20
30
40
50
60
70
80
90
0 2 4 6 8 10 12
Low
Tem
p. P
G G
rad
e (
C)
Hig
h T
emp
. P
G G
rad
e (
C)
Dosage (%)
0.28 RBR (Tx PG 64-22 | 0.1 TxRAP | 0.18 TxMWAS | T)
Original G*/sin(d) RTFO G*/sin(d) PAV m-controlled PAV S-controlled
B (6.0,-23)
A (6.0,70)
Target Grade: 70-22
Blend Grade: 70-23
DTc = -9.0 C
Selected Dosage: 6.0%
RECYCLED BLENDS:
– Virgin binder +
– Recycled binder(extracted & recovered) +
a) No recycling agent
b) Low dosage(2% or 5%)
c) Higher dosage(~10%)
College Station, TX Transportation Short Course October 10, 2017
RECYCLING AGENT DOSAGE SELECTIONQUICK METHOD
• RECYCLED MATERIALS:
– Virgin binder
– Recycled binder(extracted & recovered)
• No recycled blends
• High-Temp PG only
• Unaged only
67.772.5
59.4
83.5
-44
-32
-20
-8
4
16
28
40
52
64
76
88
100
112
-44
-32
-20
-8
4
16
28
40
52
64
76
88
100
112
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
RA
P B
ind
er C
on
tin
uou
s P
G (⁰C
)
Vir
gin
Bin
der
Con
tin
uou
s P
G (⁰C
)
RBR
WI PG 58-28 + 0.31 WI RAP and WI PG 58-28 + 0.5 WI RAP
Measured Continuous PGH 0.31 RBR Measured Continuous PGH 0.5 RBR
College Station, TX Transportation Short Course October 10, 2017
RECYCLING AGENT DOSAGE SELECTIONQUICK METHOD
College Station, TX Transportation Short Course October 10, 2017
• Estimate the High-Temp PG of the blend
• Estimate the recycling agent dosage
𝑹𝒆𝒄𝒚𝒄𝒍𝒊𝒏𝒈 𝑨𝒈𝒆𝒏𝒕 (%) = 𝑷𝑮𝑯𝑩𝒍𝒆𝒏𝒅 − 𝑷𝑮𝑯𝑻𝒂𝒓𝒈𝒆𝒕 / 𝟏.𝟕𝟐
𝑹𝒆𝒄𝒚𝒄𝒍𝒊𝒏𝒈 𝑨𝒈𝒆𝒏𝒕 (%) = 𝑷𝑮𝑯𝑩𝒍𝒆𝒏𝒅 −𝑷𝑮𝑯𝑻𝒂𝒓𝒈𝒆𝒕 / 𝐬𝐥𝐨𝐩𝐞 𝐫𝐚𝐭𝐞
𝑷𝑮𝑯𝑩𝒍𝒆𝒏𝒅 = 𝑹𝑨𝑷𝑩𝑹 × 𝑷𝑮𝑯𝑹𝑨𝑷 + (𝑹𝑨𝑺𝑩𝑹 × 𝑷𝑮𝑯𝑹𝑨𝑺) + (𝑩𝑩𝑹 × 𝑷𝑮𝑯𝑩𝒂𝒔𝒆)
WHAT ABOUT BLENDING?
• Most DOTs assume 100% RAP/RAS binder blending
• In reality…
100% BlendingPerfect Blending
0% BlendingBlack Rock
PARTIAL BLENDING
College Station, TX Transportation Short Course October 10, 2017
WHAT FACTORS AFFECT BLENDING?
93.0%86.1%
67.5%
40.1%
0%
20%
40%
60%
80%
100%
RAP 1 RAP 2 RAP 3 RAP 4
Bin
der
Ble
nd
ing
RAP aging
4.27% 4.50%
5.11%
6.01%
2%
3%
4%
5%
6%
7%
8%
RAP 1 RAP 2 RAP 3 RAP 4
RA
P b
ind
er c
on
ten
t af
ter
mix
ing
wit
h v
irgi
n b
ind
er
Artificial RAP
0% Blending
100% Blending
40.8%
73.4%
43.7%
75.6%
53.0%
86.9%
0%
20%
40%
60%
80%
100%
TX RAP NH RAP
Bin
de
r B
len
din
g
RAPRAP+RA (added to the binder)RAP+RA (added to the RAP)
107.6 90.0High Temp PG
Stiffer RAP yielded lower binder
blending
College Station, TX Transportation Short Course October 10, 2017
WHAT FACTORS AFFECT BLENDING?
93.0%86.1%
67.5%
40.1%
0%
20%
40%
60%
80%
100%
RAP 1 RAP 2 RAP 3 RAP 4
Bin
der
Ble
nd
ing
RAP aging
4.27% 4.50%
5.11%
6.01%
2%
3%
4%
5%
6%
7%
8%
RAP 1 RAP 2 RAP 3 RAP 4
RA
P b
ind
er c
on
ten
t af
ter
mix
ing
wit
h v
irgi
n b
ind
er
Artificial RAP
0% Blending
100% Blending
40.8%
73.4%
43.7%
75.6%
53.0%
86.9%
0%
20%
40%
60%
80%
100%
TX RAP NH RAP
Bin
de
r B
len
din
g
RAPRAP+RA (added to the binder)RAP+RA (added to the RAP)
107.6 90.0High Temp PG
Marginal increase when the recycling agent was added to
the binder
College Station, TX Transportation Short Course October 10, 2017
WHAT FACTORS AFFECT BLENDING?
93.0%86.1%
67.5%
40.1%
0%
20%
40%
60%
80%
100%
RAP 1 RAP 2 RAP 3 RAP 4
Bin
der
Ble
nd
ing
RAP aging
4.27% 4.50%
5.11%
6.01%
2%
3%
4%
5%
6%
7%
8%
RAP 1 RAP 2 RAP 3 RAP 4
RA
P b
ind
er c
on
ten
t af
ter
mix
ing
wit
h v
irgi
n b
ind
er
Artificial RAP
0% Blending
100% Blending
40.8%
73.4%
43.7%
75.6%
53.0%
86.9%
0%
20%
40%
60%
80%
100%
TX RAP NH RAP
Bin
de
r B
len
din
g
RAPRAP+RA (added to the binder)RAP+RA (added to the RAP)
107.6 90.0High Temp PG
Higher blending when recycling
agent was added to the RAP
College Station, TX Transportation Short Course October 10, 2017
RAP CHARACTERISTICS
Source PGContinuous
High-Temp PG (°C)Continuous
Low-Temp PG (°C)ΔTc (°C)
Texas — 106.6 -2.4 -9.8
Indiana 88-10 90.4 -13.7 -6.2
Nevada 82-16 84.4 -20.4 -3.4
New Hampshire
88-16 90.2 -20.6 -2.1
Wisconsin 82-10 83.5 -10.9 -7.3
Delaware 82-10 86.2 -13.8 -4.4
TAKEAWAYS
• There is a push to increase the amount of recycled materials in asphalt mixtures.
• But, construction and performance issues still exist.
• It is possible to increase the amount of recycled materials by incorporating recycling agents.
• There are many recycling agents currently available and not a standard way of selecting the “right one”.
College Station, TX Transportation Short Course October 10, 2017
TAKEAWAYS
• There are ways of estimating the recycling agent dosage with minimal testing.
• Partial blending occurs between the recycled materials binder and the virgin binder in the mixture.
• Degree of blending depends on the characteristics of the recycled materials (aging) and how the recycling agent is added to the mixture.
College Station, TX Transportation Short Course October 10, 2017
THANK YOU!
Edith Arámbula Mercado(979) 458-0209
Amy Epps Martin(979) 862.1750