2026-07-01T01:52:59Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/63722022-12-02T12:41:55Zcom_10259_6171com_10259_5086com_10259_2604col_10259_6172

Revilla Cuesta, Víctor Evangelista, Luís Brito, Jorge de Skaf Revenga, Marta Ortega López, Vanesa 2022-01-31T09:28:02Z 2022-01-31T09:28:02Z 2022-01 0950-0618 http://hdl.handle.net/10259/6372 10.1016/j.conbuildmat.2021.125726 The high strength and durability of high-performance concrete (HPC) may be significantly reduced by shrinkage cracking. The use of reactive magnesium oxide (MgO) can reduce shrinkage of cement-based materials due to its expansive properties. This study intends to analyse the validity of MgO as shrinkage-reducing agent in recycled aggregate HPC. To do so, ten HPC mixes with 0%, 25%, and 100% of both early-age (7-days air curing) and matured (6-month air curing) RA were produced. In half of the mixes, 10% ordinary Portland cement was replaced with MgO. The use of MgO slightly worsened the mechanical behaviour of HPC, especially when combined with large amounts of RA. On the other hand, the expansion of MgO fully offset the autogenous shrinkage of HPC and reduced total shrinkage by around 20–40%. Water storage of RA, and its deferred release over time, produced a more efficient hydration of MgO, which in turn led to a further reduction of autogenous shrinkage. However, the increase of drying shrinkage caused by RA was greater than this decrease of autogenous shrinkage due to MgO, so the higher the RA content of HPC the lower the total shrinkage reduction when adding MgO. Thus, the decrease of total shrinkage caused by MgO was compensated by the shrinkage increase because of RA when adding amounts above 35% early-age RA and 42% matured RA. Therefore, despite the suitability of MgO as shrinkage-reducing agent in recycled aggregate HPC, its effectiveness was reduced with increasing amounts of RA. Spanish Ministry of Universities, MICINN, AEI and ERDF [grant numbers FPU17/03374; EST19/00263; PID2020-113837RB-I00; 10.13039/501100011033]. The authors also acknowledge the support of the Foundation for Science and Technology, CERIS Research Centre and Instituto Superior Técnico, the Junta de Castilla y León [grant number UIC231], and the University of Burgos [grant number Y135.GI]. eng Elsevier Construction and Building Materials. 2022, V. 314, Part B, 125726 https://doi.org/10.1016/j.conbuildmat.2021.125726 info:eu-repo/grantAgreement/MICIU/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/FPU17%2F03374 info:eu-repo/grantAgreement/MIU//EST19%2F00263 info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-113837RB-I00/ES/ESTUDIO A ESCALA REAL DE HORMIGONES SOSTENIBLES, HIDRAULICOS Y BITUMINOSOS, DE ALTAS PRESTACIONES, FABRICADOS CON RESIDUOS SIDERURGICOS Y DE CONSTRUCCION info:eu-repo/grantAgreement/UBU//Y135.GI Attribution-NonCommercial-NoDerivatives 4.0 Internacional http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess High-performance concrete Recycled aggregates Recycled aggregate’s maturity Magnesium oxide Autogenous shrinkage Drying shrinkage Ingeniería civil Materiales de construcción Civil engineering Building materials Mechanical performance and autogenous and drying shrinkage of MgO-based recycled aggregate high-performance concrete info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Construction and Building Materials 314 125726