Concrete Test Section RPF 8 May 2002

Objectives Design details Material properties Instrumentation Traffic Construction Conclusion Outline

To calibrate cncRisk at the lower end of the traffic spectrum To quantify failure of low-volume concrete pavements Objectives

Cement and Concrete Institute CSIR Transportek University of Pretoria Alpha Stone and Readymix BKS Raubex Parties

University of Pretoria Section 1 75 mm SFRC (30 kg/m3) Joint spacing 3 m 140 mm Foam concrete subbase In situ Section 2 75 mm SFRC (30 kg/m3) Joint spacing 6 & 4 m 125 mm CTS In situ Design details

University of Pretoria (cont) Section 3 75 mm SFRC (30 kg/m3) No joints 25 mm ETB 125 mm CTS In situ Design details

CSIR Transportek Section 4 50 mm “CRCP” 50 mm ETB 125 mm CTS In situ Section 5 75 mm “CRCP” 25 mm ETB 125 mm CTS In situ Design details

CSIR Transportek Section mm “CRCP” 125 mm CTS In situ Design details

C&CI Section mm butt jointed Joint spacing 2 and 3 m 125 mm CTS In situ Section mm butt jointed Joint spacing 2 and 3 m 40 mm continuously graded asphalt 100 mm CTS In situ Design details

C&CI Section mm jointed Joint spacing 2, 3 and 4 m 125 mm gravel In situ Section mm butt jointed Joint spacing 2, 3 and 4 m 125 gravel In situ Design details

C&CI Section mm dowel jointed Joint spacing 2, 3 and 4 m Dowels c/c 125 mm gravel In situ Design details

In situ CBR80 Quartzitic gravel A-1-a G5/G6 Compaction 97% Mod. AASHTO FWD deflections  1,0 mm Material Properties

Subbase As in situ Compaction 97% Mod. AASHTO Stabilized with 2% CEM I 42.5 (C3) (Recycler) UCS  2000 kPa FWD deflection 0,9 mm and Stab 0,5 mm Material Properties

ETB Subbase material Stabilized with 1,5% anionic stable grade 60%, 1% cement Asphalt Continuously graded hot mix with 60/70 pen 12 mm aggregate size Material Properties

Concrete Strength f c MPa f f 3,7 - 5,6 MPa Mod E GPa Shrinkage0,05 - 0,06 % CementCEM I 42,5/GGBS 80/20 Material Properties

LVDT’s Centre Side Thermocouples Conventional Programmable MDD’s Weather station Instrumentation

Readymix concrete Compaction by poker and beam Curing compound Plastic sheeting Construction

Trucks leaving quarry Weighbridge data No of axles Approximately 300 E80’s per day To date E 80’s Traffic

Very little distress to date Vertical movement at joints under traffic but no relative movement Rocking of slabs on foam concrete Some corner breaks Plastic shrinkage cracks not affecting performance Observations

Ongoing observations Continual recording of instruments to end May Panel to define failure Analysis of results Availability of data Future

Thank you