MODELING OF RIGID PAVEMENTS ON CLAYEY SUBGRADES OF LOW AND MEDIUM PLASTICITY IN RESIDENTIAL ROADS IN SINCELEJO CITY

Abstract

Rigid concrete pavements are frequently used structures as a surface layer on the main roads of the world. This is due to its remarkable advantages that have made them a very attractive design alternative for streets and roads of different hierarchical level, both for low and high volumes of transit. This type of paving presents a somewhat high initial investment, if compared to asphalt pavements, but if they are designed and built in a adequate, maintenance during its service life is minimal or non-existent; that's why, in those roads where there are few resources for the maintenance of the themselves, turns out to be a viable alternative. Example of the above, are the streets of neighborhoods residential, where commercial vehicle traffic is low and it is sought that the pavement is kept in optimal conditions for long periods of time. The objective of this work is to present the modeling of various rigid pavement structures for roads in the city of Sincelejo, north of Colombia, in neighborhoods with residential streets, where the predominant traffic is light vehicles such as cars and trucks and where trucks rarely pass. Additionally, sites have been selected where subgrade soils of a fine nature of low or medium plasticity are found and which, in addition, have low values of bearing capacity. For purposes of the present investigation, the clayey soils found were characterized, in order to obtain its physical, mechanical and bearing capacity properties, from the analysis of 51 samples obtained. For the modeling of the pavement structures, the PCA method was used, taking the concrete pavement slab as a typical structure, a granular subbase and an improvement in selected material, to increase the capacity bearing of the pavement foundation. To carry out the modeling, 8 levels of concrete resistance were taken into account, for which the modulus of rupture was varied from 3.8 MPa to 4.5 MPa, in intervals of 0.1 MPa and work was done with reaction modules of the improved subgrade of 41, 46 and 49 MPa/m. In addition, we worked with the single wheel, single double wheel and tandem axles of two design trucks, a C2 and a C3, typical trucks that sometimes circulate on these roads and that correspond to the city's garbage collection trucks. The results obtained show the minimum values of slab thickness that these pavements must have to guarantee good performance during the design period. According to the results obtained, the truck that turned out to be more critical was the type C2 and the type of failure that predominated in the modeling was the Fatigue criterion. Additionally, the years of service that certain typical pavement structures that have been built in some parts of the city may have were estimated and it was possible to determine that their design periods are between 4 and 7 years, quite low values for the investment that a pavement represents and the useful life that it can have if it is well designed. Finally, some models were made to review the stresses in the aforementioned pavement structures, thus obtaining by means of EverFE software, the values of deformation and stresses on the paving slab.