RIGID PAVEMENT DESIGN

1. The design wheel load is first decided based on relevant axle load studies and analysis as we explained.
2. Based on the Locality where the pavement is to be constructed and the data on the topography, climatic and other factors the temperature differential for various pavement thicknesses are estimated.
3. The supporting layer of the rigid pavement such as sub grade, sub base and base course layer are decided and the sub grade modulus is either determined or estimated.
4. As the warping stresses dependent on the length and width of the pavement Slab it is necessary at this stage to decide the spacing between the longitudinal and traverse joint, the spacing between contraction joint, Lc to be provided during the initial period of curing of concrete is decided.
5. A trail thickness of pavement is first assume the load and warping stress value at pavement edge are determined using the appropriate stress equation or chart for his assumed trail thickness of pavement. If total value of stresses exceeds the permissible limit, the trial is repeated assuming a higher pavement thickness.
6. The factor of safety of the trial thickness of pavement is worked out by taking the ratio of flexural strength of the pavement to the combined flexural stress at edge region due to the design wheel load and warping during summer mid way.
7. If the assumed thickness of pavement fails to fulfil any of the above requirements, the next trial is made after suitably revising the thickness.
8. The total of the edge load stress due to heaviest load and the edge warping stress on summer mid way is calculated, if the total stress is less than the flexural strength of CC (45 kg /cm^2),the Design is accepted.