Papers

@article{rodriguez-alvaro_effect_2025,

title = {Effect of fly ash blending in internally cured mortar under air-drying curing conditions},

author = {Roberto Rodríguez-Álvaro and Sindy Seara-Paz and Blas Cantero-Chaparro and Belén González-Fonteboa},

url = {https://www.sciencedirect.com/science/article/pii/S0950061825036402},

doi = {10.1016/j.conbuildmat.2025.143489},

issn = {0950-0618},

year  = {2025},

date = {2025-10-01},

urldate = {2025-10-01},

journal = {Construction and Building Materials},

volume = {495},

pages = {143489},

abstract = {A proper humid curing of concrete structures is commonly considered as vital to guarantee their strength development and durability. However, undesired periods of air-drying curing conditions can take place. Therefore, the performance of concrete in this situation should be studied. This research work aims to better understand how internally cured fly ash blended cement mortars are affected by air-drying curing conditions. Coal bottom ash (CBA) and wood bottom ash (WA) were used as internal curing water reservoirs. Results show a poor strength development after the age of one week. Moreover, mortar specimens lose a considerable amount of weight during their first days of curing due to water evaporation. This severe drying, together with a long-term carbonation (depth, weight gain and shrinkage), affects the fly ash (FA) blended cement mortars more than the ordinary Portland cement (OPC) mortars. Furthermore, a pore structure analysis was carried out, showing that FA-blended mixtures present a higher total porosity and internal curing cannot effectively refine the pores in the matrix when OPC is the only binder. Self-desiccation was detected in combination with external drying thanks to a comparative study between weight changes and shrinkage. Internal curing can mitigate the self-desiccation shrinkage but increases the drying shrinkage. Moreover, the presence of the waste porous aggregates counteracts the internal curing effect decreasing the strength, and barely affects the carbonation process. As a general conclusion, it can be stated that air-drying curing conditions should be avoided and external wet or sealed curing should always complement internal curing, especially if blended cements are used.},

keywords = {Carbonation, Coal bottom ash, Drying shrinkage, Self-desiccation, Weight change, Wood bottom ash},

pubstate = {published},

tppubtype = {article}

}

@article{rodriguez-alvaro_internally_2020,

title = {Internally cured high performance concrete with magnesium based expansive agent using coal bottom ash particles as water reservoirs},

author = {Roberto Rodríguez-Álvaro and Belén González-Fonteboa and Sindy Seara-Paz and Khandaker M. A. Hossain},

url = {https://www.sciencedirect.com/science/article/pii/S095006182030982X},

doi = {10.1016/j.conbuildmat.2020.118977},

issn = {0950-0618},

year  = {2020},

date = {2020-08-01},

urldate = {2026-08-06},

journal = {Construction and Building Materials},

volume = {251},

pages = {118977},

abstract = {Shrinkage is one of the main concerns related to high performance concrete (HPC) durability. Its high density paste, consequence of a low water to binder ratio, can be unprofitable if cracks appear due to excessive tension when volume changes are restrained. Therefore, volume stability is a priority. In this work, three different strategies have been studied with that purpose: integration of fly ash as a low reactive supplementary cementitious material, internal curing via coal bottom ash particles as water reservoirs and the use of an expansive agent based on magnesium oxide (MEA). Many research works address the three shrinkage reduction strategies individually. However, studies regarding their simultaneous use are not prevalent so this work proposes its combined application. Results indicate that internal curing and MEA have a synergistic effect in HPC. Internal curing enhances MEA expansion due to the lack of water in this kind of concrete, contributing to autogenous shrinkage compensation. When concrete is affected by air-drying conditions, the use of MEA, internal curing, or both together make shrinkage to increase. MEA effectively expands in wet cured HPC although internal curing is not effective in this condition due to the absence of self-desiccation and limited porous aggregate water desorption. Taking into account the effects of each shrinkage reduction strategy and curing condition, it has been concluded that the use of fly ash as supplementary cementitious material, internal curing and MEA is recommended together with prevention of water evaporation from HPC surface.},

keywords = {Autogenous shrinkage, Coal bottom ash, Drying shrinkage, Fly ash, Internal curing, Magnesium based expansive agent, Swelling},

pubstate = {published},

tppubtype = {article}

}