Over the years, Portland cement concretes have undergone increasing demands for constructability, cost, quality, and environmental impact. These demands were met, mainly, through changes in the cement composition and the introduction of chemical admixtures. In this sense, through a literature review, the authors sought to create a collection of information on the evolution of these materials and their standards from 1937 to 2020 in Brazil . This work is part of a research project that aims to elaborate a dating protocol for Brazilian concretes. From the review conducted, the authors observed that the absence of systematic records in the Brazilian civil construction sector hinders the attempt to create a chronology of the development of concrete in the country. In addition, we concluded that the knowledge of the evolution of Portland cement and chemical admixtures is relevant information that can assist in concrete dating processes. The reliable comparison data, posteriorly combined with microstructural characterisation techniques, may lay the basis for an effective dating methodology.

Este trabalho teve por objetivo apresentar alguns casos de fissuração do concreto em travessa de apoio de pontes em concreto. São comentados seis casos ocorridos em pontes de concreto, onde se relatam os problemas encontrados, as causas da fissuração e as possíveis soluções para estes casos. Há causas de fissuração do concreto relacionadas à corrosão das armaduras internas pela entrada de agentes agressivos no concreto ou pela corrente elétrica de fuga, e ao recalque de apoio das travessas. Verificou-se neste trabalho que a maioria das causas de fissuração se deve a falhas na execução e no projeto, detalhamento e dimensionamento desta travessa de apoio.