Concrete Test Section Concrete Test Section

RPF

8 May 2002

ObjectivesDesign detailsMaterial properties InstrumentationTrafficConstructionConclusion

OutlineOutline

To calibrate cncRisk at the lower end of the traffic spectrum

To quantify failure of low-volume concrete pavements

ObjectivesObjectives

Cement and Concrete InstituteCSIR TransportekUniversity of Pretoria

Alpha Stone and ReadymixBKSRaubex

PartiesParties

University of PretoriaSection 1

75 mm SFRC (30 kg/m3) Joint spacing 3 m140 mm Foam concrete subbase In situ

Section 275 mm SFRC (30 kg/m3) Joint spacing 6 & 4 m 125 mm CTS In situ

Design detailsDesign details

University of Pretoria (cont)Section 3

75 mm SFRC (30 kg/m3) No joints25 mm ETB125 mm CTS In situ

Design detailsDesign details

CSIR TransportekSection 4

50 mm “CRCP”50 mm ETB125 mm CTS In situ

Section 575 mm “CRCP” 25 mm ETB 125 mm CTS In situ

Design detailsDesign details

CSIR TransportekSection 6

100 mm “CRCP”125 mm CTS In situ

Design detailsDesign details

C&CISection 7

100 mm butt jointed Joint spacing 2 and 3 m125 mm CTS In situ

Section 8100 mm butt jointed Joint spacing 2 and 3 m40 mm continuously graded asphalt 100 mm CTS In situ

Design detailsDesign details

C&CISection 9

140 mm jointed Joint spacing 2, 3 and 4 m125 mm gravel In situ

Section 10140 mm butt jointed Joint spacing 2, 3 and 4 m125 gravel In situ

Design detailsDesign details

C&CISection 11

140 mm dowel jointed Joint spacing 2, 3 and 4 m Dowels 25 mm @ 300 c/c

125 mm gravel In situ

Design detailsDesign details

In situCBR 80Quartzitic gravel A-1-a G5/G6Compaction 97% Mod. AASHTOFWD deflections 1,0 mm

Material PropertiesMaterial Properties

SubbaseAs in situCompaction 97% Mod. AASHTOStabilized with 2% CEM I 42.5 (C3)

(Recycler)UCS 2000 kPaFWD deflection 0,9 mm and Stab 0,5 mm

Material PropertiesMaterial Properties

ETBSubbase materialStabilized with 1,5% anionic stable grade

60%, 1% cementAsphalt

Continuously graded hot mix with 60/70 pen

12 mm aggregate size

Material PropertiesMaterial Properties

ConcreteStrength

fc 22 - 42 MPa

ff 3,7 - 5,6 MPa

Mod E 24 - 33 GPaShrinkage 0,05 - 0,06 %Cement CEM I 42,5/GGBS 80/20

Material PropertiesMaterial Properties

LVDT’sCentreSide

ThermocouplesConventionalProgrammable

MDD’sWeather station

InstrumentationInstrumentation

Readymix concreteCompaction by poker and beamCuring compoundPlastic sheeting

ConstructionConstruction

Trucks leaving quarryWeighbridge dataNo of axlesApproximately 300 E80’s per dayTo date 14 000 E 80’s

TrafficTraffic

Very little distress to dateVertical movement at joints under traffic

but no relative movementRocking of slabs on foam concreteSome corner breaksPlastic shrinkage cracks not affecting

performance

ObservationsObservations

Ongoing observationsContinual recording of instruments to

end MayPanel to define failureAnalysis of resultsAvailability of data

FutureFuture

Thank you Thank you