Finite-element model approach to determine support conditions and effective layout for concrete block paving

Concrete block paving (CBP) is one of the predominant road construction methods used in most of the developing counties due to its economic adaptability. It has emerged as a cost-effective road construction method suitable for different ground conditions but this has yet to be developed as a full fledged technique because of the dearth of technical expertise and knowledge. The aim of this research is to evaluate the state of support conditions and to discover effective patterns which can be used to improve concrete block paving technology. Development of a laboratory scale CBP model and evaluation of support conditions were mainly considered in the initial stage of this study. A developed laboratory scale CBP model was used to measure deflection basin with four different load arrangements. A three-dimensional finite-element model was built to measure elastic deflection behavior of concrete block pavement with SAP2000 structural analysis software. This finite-element model was used to simulate field conditions of a concrete block pavement and it was verified with the deflection values observed in a laboratory scale model. The verified analytical model has been used to perform a parametric study in order to determine necessary improvements for weaker support conditions and find effective laying arrangement in the concrete block paving. Developed design charts and field observations can be used to propose subgrade improvement methods for weaker support conditions. The writers recommend concrete block laying work for low volume roads with subgrade strength higher than 10% CBR. The results indicate that herringbone bond pattern performed well under effect of vertical loading and breaking action. It has the capability to develop better interlocking action in CBP work