Roller Compacted Concrete

and the

Ready Mix Industry

Frank Lennox

Manager of Technical Services

Member of ACI 327-Roller Compacted Concrete Committee

Sub-committee chairman ASTM C9.45 Roller Compacted Concrete

RCC is not your grandfather’s

concrete!

What ready mix experience does

the speaker have???

Question #1

I have studied a manual and

have had practical experience.

Question #2

Can Roller Compacted Concrete be produced through a standard ready mix concrete plant?

The answer is

YES !

So let’s get

started

Up until 15 years ago, all

Roller Compacted

Concrete Pavement

material was produced

using a standard pug mill.

Since 1997 we have

been producing RCC

through ready mix

operations.

Is the mix design procedure

different for the ready mix

industry?

NO!You use the same procedures

as set forth by the industry!

Step 1: Optimize you aggregates

RCC Gradation Bands

Adjusted for Specific

gravity differencesAggregate Gradation Analysis

Percent Passing Sieve Combine

d (by

Volume)

Retaine

d on

Sieve

Retained

Requirem

entSand

#1

Sand

2A B C

Sieve

Size

(%) (%) (%)

10.1

%

40.7

%

24.6

%

24.6

% 0.0% 100.0

1.5" 100 100 100 100 100 100.0 0.0 0-4

1" 100 100 100 100 100 100.0 0.0 8-18

3/4" 100 100 95.2 100 100 98.8 1.2 8-18

1/2" 100 100 44.8 100 100 86.4 12.4 8-18

3/8" 100 100 26.8 99.1 99 81.8 4.6 8-18

4 95 99.8 4.2 32.4 32 59.2 22.6 8-18/ 4-8*

8 81.9 88.9 1.3 6.9 6 46.5 12.7 8-18/ 4-8*

16 74.9 52.2 0 2.1 2 29.3 17.1 8-18/ 4-8*

30 67.4 30 0 0 1 19.0 10.3 8-18

50 28.4 17.3 0 0 0.4 9.9 9.1 8-18

100 2.8 8.3 0 0 0 3.7 6.3 1.5-5.0

*Lower range

acceptable (for any

single sieve) if

aggregates are

0

10

20

30

40

50

60

70

80

90

100

11/2"

1" 3/4" 1/2" 3/8" 4 8 16 30 50 100 200

Perc

en

t P

assin

g

Sieve Size

Aggregate Gradation

Step 2: Select a cementitious

content range

A good starting point may be between

11 and 13 % for cement without the

addition of SCM’s

Strength vs. Cement Content

Step 3: Develop moisture-

density plots

For a fix cementitious %, different

moisture contents are selected using

ASTM D1557 modified Proctor.

Moisture-density curve

Put all ingredients together, mix

well, make cylinders and pray!!

OR YOU CAN DO WHAT

WE DID!

TAKE A STANDARD 4000

PSI MIX, REMOVE SOME

WATER, ADJUST THE

SAND QUANTITY AND

PRAY!

Cement 400 lbs

Fly Ash 100 lbs

#67 Stone 1800 lbs

Concrete Sand 1300 lbs.

Water 18 – 20 gals

FIRST MIX DESIGN

Material found at most ready mix concrete operations!

0

20

40

60

80

100

120

1" 3/4" 1/2" 3/8" #4 #8 #16 #30 #50 #100 #200

RCC Gradation Curve

Original Mix

Upper Lower Combined

Texture

NEW MIX DESIGN

2005

Cement 400 lbs.

Fly Ash 100 lbs.

Coarse Agg. #67 1100 lbs.

Coarse Agg. #89 or #7 ‘s 1100 lbs.

Fine Aggregate 1330 lbs.

Water 180 lbs.

Admixture Standard Water Reducer

0

20

40

60

80

100

120

1" 3/4" 1/2" 3/8" #4 #8 #16 #30 #50 #100 #200

RCC Gradation Curve 3 Aggagates

Sequatchie Concrete Products

Upper Lower Combined

Gradation curve for 3 aggregates

Texture: New Mix

After using this mix for

several years, we still

were not happy!

What were

we going to

do??

So, we went back to the lab!

We

needed to

make it

look

better!!

EVEN NEWER MIX DESIGN

2012

Cement 375 lbs.

Fly Ash 125 lbs.

Coarse Agg. #67 850 lbs.

Coarse Agg. #89 or #7 ‘s 850 lbs.

Fine Aggregate - Mfg. 1415 lbs.

Fine Aggregate – Natural 350 lbs.

Water 180 lbs.

Admixture Standard Water Reducer

0

20

40

60

80

100

120

1" 3/4" 1/2" 3/8" #4 #8 #16 #30 #50 #100 #200

RCC Gradation Curve 4 Aggregates

Sequatchie Concrete Products

Upper Lower Combined

Gradation curve for 4 aggregates.

Adjusted for Specific

gravity differencesAggregate Gradation Analysis

Percent Passing Sieve Combine

d (by

Volume)

Retaine

d on

Sieve

Retained

Requirem

entSand

#1

Sand

2A B C

Sieve

Size

(%) (%) (%)

10.1

%

40.7

%

24.6

%

24.6

% 0.0% 100.0

1.5" 100 100 100 100 100 100.0 0.0 0-4

1" 100 100 100 100 100 100.0 0.0 8-18

3/4" 100 100 95.2 100 100 98.8 1.2 8-18

1/2" 100 100 44.8 100 100 86.4 12.4 8-18

3/8" 100 100 26.8 99.1 99 81.8 4.6 8-18

4 95 99.8 4.2 32.4 32 59.2 22.6 8-18/ 4-8*

8 81.9 88.9 1.3 6.9 6 46.5 12.7 8-18/ 4-8*

16 74.9 52.2 0 2.1 2 29.3 17.1 8-18/ 4-8*

30 67.4 30 0 0 1 19.0 10.3 8-18

50 28.4 17.3 0 0 0.4 9.9 9.1 8-18

100 2.8 8.3 0 0 0 3.7 6.3 1.5-5.0

*Lower range

acceptable (for any

single sieve) if

aggregates are

0

10

20

30

40

50

60

70

80

90

100

11/2"

1" 3/4" 1/2" 3/8" 4 8 16 30 50 100 200

Perc

en

t P

assin

g

Sieve Size

Aggregate Gradation

If you can make Pervious Concrete

You can make Roller Compacted Concrete!

ASTM

SUBCOMMITTEE

C09.45 Roller Compacted

Concrete

C 1040 In-Place density Nuclear Methods

C 1170 Consistency & Density Vibrating Table

C 1176 Cylinder Molds – Vibrating Table

C 1435 Cylinder Molds – Vibrating Hammer

ASTM Test Procedures for RCC

ASTM update for Roller Compacted

Concrete

Test Method for molding beams

Reason: A method for determining the

flexural strength of RCC mix design used

in pavements

Equipment: ASTM C 1435 vibrating

hammer with a square tamping plate,

rectangular steel beam molds as used in

ASTM C 31, and testing as per ASTM C

78.

ASTM update for Roller Compacted

Concrete

Test Method for Density and Air Content

Reason: There have been signs of freeze-

thaw damage to some RCC dams in

higher elevation.

Equipment: Standard pressure air meter

ASTM C 231 and standard vibrating

hammer as in C 1435.

ASTM update for Roller Compacted

Concrete

Test Method for preparation compaction

and density using Gyratory compactor.

Reason: To find a way to establish a

consistent method for producing RCC

specimens using gyratory compacting

technology.

Equipment: Gyratory Compactor as per

D 6925

NRMCA.ORG

CEMENT.ORG