Paper by GAMIZ from ISCR 8th 1998 Lisbon Portugal
This paper addresses the appraisal and management procedure used for more than 20 years by a toll motorway concessionaire, covering a total of 300 kilometres of concrete dual carriageway built between 1970 and 1985. The system of analysis, surveys and experiments carried out during this period was based on auscultations evaluated by tried and tested behaviour models. Periodic auscultation provided the data necessary to determine the superficial and structural characteristics of the roadway. Data was nhtained from visual and mechanical auscultations; both procedures are detailled in the paper. Visual auscultarion detei lililles certain parameters (cracking, deterioration, movement, fracture and critical indices) concerning the different aspects which affect roadway structures. When weighted and studied together, they give the Condition Index: a true picture of the roadway condition rated from 0 (total ruin) to 100 (perfect). Defleeliuus were measured by applying different loads to joints and slab centres, taking into account where the loads were applied, their distance from the edge of the slab and the thermal gradient state of the slab. The slab load transfer coefficient, modulus, size of the hole, if any, and its possible cause were calculated by an empirical and mathematical model. Our experience enabled us to combine these parameters to rate the Structural Index from 1 to 10. These data enabled the roadway condition to be assessed in terms of two basic criteria: Condition Index, IE1, obtained from visual auscultations Structural Index, 1E2 obtained from mechanical auscultations, which in turn made it possible to evaluate: Scheduled maintenance operations Preverilive maintenance operations Estimated life span Roadway sectioning according to forecast growth. The management procedure set forth in this paper deals with finding the necessary investment at the right moment by optimising the execution of the operations mentioned above.