Statistical Characterization of Prestressed Concrete Road Bridge Decks

The present paper presents a study to statistically characterise 87 prestressed concrete bridge decks of real flyovers of constant depth. The main objective of the study is to find design formulae with the least number of data so as to improve the preliminary design of this type of structures. The study performs an exploratory analysis and a multivariant analysis of the geometrical variables, the amount of materials and the cost, both for voided decks and for non-voided decks. The regression models have allowed to predict the depth and the prestressing active reinforcement as a function of the span, while the amount of concrete results a function of the depth of the deck. The variable that better explains (71.3%) the cost per unit surface of the deck in non-voided bridges is the depth, while for voided decks is the main span (51.9%). Non-voided decks are economical for spans inferior to 19.24 m. The main span and the external void together with de width of the deck for non-voided slabs or the interior voids in the case of voided slabs are enough to find the preliminary design of the slab with reasonable accuracy for the economic assessment of the design.