Introduction of a Laboratory-Based Mix Design Method for Roller Compacted Concrete Pavements in El Salvador

This paper presents a laboratory-based mix design method for roller compacted concrete pavements for optimizing their cost-performance. It consists in introducing a new design procedure based on laboratory tests for aggregates, sand/gravel ratio, cement/water ratio, cement content, and resistance of the specimens to compression and flexion, in order to establish a method enabling to find functional and economical mixes for compacted concrete to be applied to a road rehabilitation plan in a systematically managed way. The method involves laboratory tests of materials and components of concrete, computerized analysis of the results, the use of a newly designed method of compaction for concrete samples in laboratory, and a new procedure for optimizing the cement content of a mix to attain the required resistance. Roller compacted concrete has not yet being widely used for pavement structures in Latin America, and the procedure described in this paper defining the optimal mix iterative testing steps might be applicable to the other similar projects. It is worth to noting that the concepts used in this method, and the equipment fabricated or existing but adapted for the requirements, have recently been applied successfully to the pavement design for the Project for Reconstruction of Major Transportation Infrastructure in the Republic of El Salvador for the Ministry of Public Works of El Salvador in Central America.