Analysis of the evolution of the sizing parameters of concrete reservoirs

Abstract

Concrete reservoir is a hydraulic unit of water accumulation and passage which must have a useful life to fulfill the function for which it was designed. For this, it is essential that the structure is watertight, which is possible when the design and execution respect characteristics such as compressive strength of the concrete, minimum reinforcement cover, water/cementratio, adequate waterproofing of the structure. If these characteristics do not occur, the concrete may deteriorate and the reinforcement will be subject to corrosion when the reserved water has chlorides, sulfates at high contents and low pH, coming into contact with concrete through pores or cracks. From the inductive method, with the documentary analysis, the present study aimed at a historical analysis of the current NBR 6118, from 1940, and the orders of the Ministry of Health on the use of chlorine and sulfate, in order to relate the parameters used in the design of the reservoirs with the degradation of these structures. The study of nineteen concrete reservoirs, within a thirty-nine-year horizon, initially demonstrated that standard design parameters and physical and chemical parameters evolved in favor of the safety of these structures. Finally, for the design of the reservoirs, the design characteristics were not observed, favoring the beginning of the corrosion in the reinforcement.