FRLP - I+D+i - CENTROS - LEMAC - TRABAJOS DE INVESTIGACIÓN

Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/1756

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Author: search.filters.author.Zega, Claudio JavierSubject: search.filters.subject.Mixture proportioning

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    Durable performance of recycled aggregate concrete in aggressive environments
    (2020) Zega, Claudio Javier; Santillán, Lautaro; Sosa, María Eva; Villagrán Zaccardi, Yury Andrés
    Recycled aggregate concrete is an eco-friendly material that is increasingly being used in new constructions. Nowadays, this application is mainly limited by user’s lack of confidence, as coarse recycled aggregate (CRA) is usually more porous, i.e., it has a higher water absorption, than coarse natural aggregate. This difference is a primary concern for practitioners when they have to comply with durability requirements. Although some uncertainties remain in this regard, significant progress has been made in the last few years concerning the assessment of durable recycled aggregate concrete. This paper reviews this topic and includes aspects related to chloride penetration, sulfate attack, freezing and thawing, high temperature, and alkali-silica reaction. Generally, although there are some particularities related to each type of attack, the high porosity of CRA is compensated by other features, such as different texture, increased mechanical compatibility with the matrix, or content of hydration products. Experimental results in the literature show that there are no reasons to consider that durable, sustainable structures cannot be built with recycled aggregate concrete.
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    Optimizing manufactured sand content in mortars and its influence on fresh and hardened state
    (2020) Sosa, María Eva; Chirrillano, Andrés; Villagrán Zaccardi, Yury Andrés; Zega, Claudio Javier
    The shape and roughness of aggregates play a predominant role in the properties of cement mixes. Due to that, some regulations limit the content of manufacture fine aggregate at 30% of the total of fine aggregate in concrete. However, few design methods consider the shape and roughness surface of aggregates in the mix proportioning. This study presents an optimization method to increase the percentage of manufactured fine aggregates to be used, based on the void volume of the aggregates and their correlation with the fresh properties of mortars. To achieve that, the characteristics of the fresh and hard state were evaluated in order to carry out a comprehensive analysis on the influence of the method on the performance of mortars. From the results emerges that it is possible to maximize the content of manufactured aggregates without detrimental effects on compressive strength.