61 documents found, page 1 of 7
Ternary blends for self-compacting mortars production composed by electric arc ...
Lopez-Uceda, Antonio; Cantador, David; Raposeiro Da Silva, Pedro; De Brito, Jorge; Fernandez Rodriguez, Jose Maria; Jimenez, Jose RamonThis study is framed within the circular economy model through the valorisation of industrial by-products. This research shows the results of producing self-compacting mortars (SCMs) with electric arc furnace dust (EAFD) and other industrial by-products such as fly ash, conforming (FA) or not conforming (NcFA), from coal-fired power plants, or recovery filler (RF) from hot-mix asphalt plants. Three batches of S...
Improvement of the quality of recycled concrete aggregate subjected to chemical...
Forero, Javier A.; De Brito, Jorge; Evangelista, Luis; Pereira, CláudioThe main factor that alters the quality of recycled concrete aggregate (RCA) is the paste adhered to the natural aggregate (NA). Since it causes weakening of the interfacial transition zone (ITZ) between the aggregate and the cementitious paste, it becomes a determining factor for the mechanical behavior of concrete. It turns out that it is critical to enhance this interface by improving the surface of the aggr...
Fracture behaviour of concrete with reactive magnesium oxide as alternative binder
Forero, J. A.; Bravo, M.; Pacheco, João; De Brito, Jorge; Evangelista, LuisThis research evaluates the fracture behavior of concrete with reactive magnesium oxide (MgO). Replacing cement with MgO is an attractive option for the concrete industry, mainly due to sustainability benefits and reduction of shrinkage. Four different MgO's from Australia, Canada, and Spain were used in the concrete mixes, as a partial substitute of cement, at 5%, 10%, and 20% (by weight). The fracture toughne...
Durability and shrinkage performance of concrete made with coarse multi-recycle...
Silva, Stefano; Evangelista, Luis; De Brito, JorgeSince construction is one of the most environmental impacting activities in existence, it is important to study and develop solutions to make its processes more efficient. Thus, multiple-recycling of concrete presents itself as a possible alternative for the reutilization of construction and demolition waste (CDW) over a large period of time. This paper presents the results and conclusions obtained from an exte...
Performance of mortars with commercially-available reactive magnesium oxide as ...
Bravo, Miguel; Forero, Javier A.; Nobre, José; De Brito, Jorge; Evangelista, LuisThis paper intends to analyze the performance of mortars with reactive MgO, as a sustainable alternative to cement. Six different MgOs from Australia, Canada, and Spain were used in the production of mortars as partial substitutes for cement, namely 5%, 10%, 15%, 20%, and 25% (by weight). MgOs with different levels of reactivity were used to analyze its influence on the performance of MgO mortars. In order to e...
Magnesia (MgO) production and characterization, and its influence on the perfor...
Nobre, José; Hawreen, Ahmed; Bravo, Miguel; Evangelista, Luis; De Brito, JorgeThis paper presents a literature review concerning the characteristics of MgO (magnesium oxide or magnesia) and its application in cementitious materials. It starts with the characterization of MgO in terms of production processes, calcination temperatures, reactivity, and physical properties. Relationships between different MgO characteristics are established. Then, the influence of MgO incorporation on the pr...
On the development of a technical specification for the use of fine recycled ag...
Bravo, Miguel; Duarte, António P. C.; De Brito, Jorge; Evangelista, Luís; Pedro, DiogoThe possibility of using recycled aggregates from construction and demolition waste (CDW) in concrete is rather widely agreed upon when it comes to the use of coarse recycled aggregates. However, this is not the case when fine recycled aggregates (FRA) are considered, as it is deemed that these seriously impair the behaviour of concrete. Hence, this work presents a technical specification proposal for the use o...
High-performance self-compacting concrete with recycled aggregates from the pre...
Barroqueiro, Tiago; Raposeiro Da Silva, Pedro; De Brito, JorgeThe main objective of this paper is to provide the industry with a simple and practical way of disposing and recovering recycled waste from precast reinforced concrete elements rejected during the quality control process, while minimizing the consumption of natural resources in the production of concrete and, consequently, significantly reducing the environmental impact of both (construction and demolition wast...
Uncertainty of shear resistance models: Influence of recycled concrete aggregat...
Pacheco, João; De Brito, Jorge; Chastre, Carlos; Evangelista, LuisThe model uncertainty of the shear resistance equations of three design codes {the current Eurocode 2 (2004), Model Code (2010), and the final draft of the Eurocode 2 (2020)} was investigated for coarse natural and recycled aggregate concrete beams. Databases of beams with and without shear reinforcement were made with clearly defined criteria. The statistics of the model uncertainty of natural and recycled con...
Fresh-state and mechanical properties of high-performance self-compacting concr...
Barroqueiro, Tiago; Raposeiro Da Silva, Pedro; De Brito, JorgeThe urgent need to change the less positive impacts of the construction industry on the environment, and more specifically the production and use of concrete, is the main motivation for the research for more efficient and environmentally sustainable solutions. This paper presented the results of an experimental campaign whose ultimate goal was to produce high-performance self-compacting concrete (SCC) using rec...