“Green” Pavement Overlays: Part I: Flexural Performance of Composite Beams on Elastic Foundation

Beams were rested on (a): rubber foundation (RF) and (b): cement stabilized aggregate foundation (CF), as part of the “Green” Pavement Overlays research programme.
The composite beams on a rubber pad foundation exhibited a load-drop after cracking of the base. Plain ordinary Portland cement concrete (OPCC) beams exhibited a peak load and failed soon after. Steel Fibre Reinforced Concrete (SFRC) beams exhibited much higher load bearing capacity than their OPCC counterparts. The augmented load carrying capacity noticed was attributed mainly to the reaction of the foundation.
Parmerter’s theory combined with Winkler’s foundation model are suitable for modelling OPCC beams on elastic foundations but not suitable for SFRC beams. However, the load bearing capacity of OPCC beams can be predicted by the above.
The elastic solid foundation model is suitable for modelling SFRC beams on elastic foundations. Finite Element Analysis is recommended to assist tests in establishing the load-CMOD (Cracked Mouth Opening Displacement) relationship. Modelling load-CMOD using this method, was in good agreement with experimental results.
Regarding SFRC-on-OPCC beams, a method for calculating the cracking load of OPCC base and the particular load value for crack entry into the SFRC overlay, was proposed and verified experimentally. This method combines Parmerter’s cracked beam theory and the principle of equivalent flexural rigidity.