Banca de DEFESA: EROS HENRIQUE DE SOUZA LIMA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : EROS HENRIQUE DE SOUZA LIMA
DATE: 12/08/2022
TIME: 09:00
LOCAL: Pos Graduação Engenharia Civil
TITLE:

Pathologies In Prestressed Concrete Sleepers: Case Study Of A Brazilian Railway

KEY WORDS:

prestressed concrete sleeper; pathologies in concrete; railroad.

PAGES: 145
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

This work aims to contribute to the study of the behavior of prestressed concrete railway sleepers. In Brazil, the prestressed concrete sleeper is the main type of sleeper used in passenger transport systems (metro) and has been increasingly used in freight railways, especially with the recent programs to encourage rail transport by the federal government. However, there are challenges in ensuring that the prestressed concrete sleepers meet expected performance standards, as many concrete sleepers fail prematurely and need to be replaced every year. Such failures have already been responsible for large-scale railway accidents which have caused financial losses and endangered the safety of rail transport users. Since the sleepers are exposed to environmental weather and subjected to cyclical loads of great intensity, they become a concrete element susceptible to pathologies of the most varied types and origins. This paper proposes to review the current literature on the main material used in the sleeper’s production and deterioration mechanisms of prestressed concrete sleepers, discuss their causes and consequences, and suggest the main corrective and preventive measures that can be taken to minimize each problem. For ease of understanding, the failures have been separated into two groups: intrinsic failures, such as failures due to internal concrete deficiencies, and extrinsic failures, such as those associated with the high impact loads of railways and freeze-thaw cycles. In general, the causes of sleeper failures are related to the use of inappropriate materials in the production of sleepers, failures in the execution of the curing and prestressing of the concrete, poor maintenance of the railway and bad conditions of the rolling stock. The present research also investigated the occurrence of pathological manifestations in sleepers of a Brazilian railroad through a case study. The sleepers were visually inspected and tested through carbonation testing, chemical analysis, petrographic analysis and scanning electron microscopy of the concrete in order to identify the pathology responsible for the sleepers' degradation. At the end of the analysis, it was concluded that the sleepers are affected by the attack of  late ettringite formation.

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