Now-a-days concrete pavements are gaining more and more importance to eliminate frequent maintenance of bituminous pavement, damaged by heavy commercial vehicles and moisture. Several types of plain concrete pavement are in use in various countries depending upon the climate, availability of materials, soil types, experience, and traffic. It is therefore necessary to improve the current pavement design with a sound analytical approach. To lower the cost of construction of concrete pavements, researchers came to a new type of concrete pavement construction named Two-Lift Concrete Pavement (TLCP). In this type of pavement construction, Pavement Quality Concrete (PQC) can be bonded to lean concrete (LC) when both layers are laid one after the other with two pavers (“fresh-on-fresh” or “wet-on-wet”). No analytical techniques are available to compute the stresses in TLCPs. To compute the stress in TLCP under various environmental and loading conditions, a finite-element programming software (ANSYS) is used. These stresses place an important role in determining the design of concrete pavements. To achieve this, a Central-Composite design with face-centered statistical design is utilised. In this design, statistical assumptions such as Normality, constant variance and Independence are checked and found that all assumptions are acceptable, but box-cox suggested to transform the model to square root. So, the model is transformed to square root form. The statistical model is validated using four random points and it is noticed that the model satisfies all the points. Conclusions are drawn from the interaction plots of the model. From the model, it is noticed that the factors such as temperature gradient over the depth of the slab and modulus of subgrade reaction are insignificant but when it interacts with other factor (PQC thickness and LC thickness), the interaction became highly significant.
Contributors: Swarna S T, Hossain K.