Papers

@article{cantero_comparative_2026,

title = {Comparative assessment of binary alkali-activated mortars incorporating construction and demolition waste under dry and CO₂ curing conditions},

author = {Blas Cantero-Chaparro and Lucas Sequeira and Jorge Brito and Miguel Bravo},

url = {https://www.sciencedirect.com/science/article/pii/S0950061826015369},

doi = {10.1016/j.conbuildmat.2026.146630},

issn = {0950-0618},

year  = {2026},

date = {2026-07-01},

urldate = {2026-08-18},

journal = {Construction and Building Materials},

volume = {530},

pages = {146630},

abstract = {Construction and demolition waste (CDW) has attracted increasing attention as a potential precursor for alkali-activated materials, although its heterogeneous nature often limits mechanical performance. This study investigates the behaviour of binary alkali-activated mortars manufactured with different types of CDW: recycled concrete (RC), recycled brick (RB) and recycled tile (RT). The combination of these precursors with 30% fly ash (FA) as a supplementary precursor was also investigated. The mixes were subjected to two curing conditions—dry and CO₂—in order to evaluate the influence of precursor mineralogy and curing regime on their mechanical and physical performance. Compressive and flexural strengths, dynamic modulus of elasticity, ultrasonic pulse velocity (UPV), porosity, shrinkage and carbonation depth were determined. The results showed that precursor reactivity governs the overall behaviour. Tile-based systems (RT) achieved the highest strengths and lowest water-accessible porosity, followed by RB, whereas RC exhibited limited reactivity. Under CO₂ curing, RT70 reached 20.3 MPa at 28 days, representing a 53.9% increase compared to dry curing. In addition, CO₂ curing reduced water-accessible porosity by up to 15%. For a comparable compressive strength, CO₂-cured mixes exhibited higher flexural strength and dynamic modulus of elasticity than those cured under dry conditions. In contrast, RC systems showed a 21.5% reduction in compressive strength at 28 days under CO₂ curing, indicating that early carbonation may adversely affect low-reactivity, calcium-rich residues. The incorporation of 30% FA mitigated this effect, increasing the 28-day compressive strength under CO₂ curing from 7.7 MPa (RC100) to 14.3 MPa (RC70). Correlation analysis confirmed an exponential relationship between mechanical performance and water-accessible porosity, highlighting the governing role of pore structure. Overall, the combined use of FA and controlled CO₂ curing offers a viable strategy for enhancing selected CDW-based alkali-activated systems.},

keywords = {Alkali-activated mortars, CO₂ curing, Construction and demolition waste, Mechanical properties, Sustainable construction materials},

pubstate = {published},

tppubtype = {article}

}

@article{cantero_optimisation_2024,

title = {Optimisation of the performance of alkali-activated mortars using CDW binders from different sources},

author = {Blas Cantero-Chaparro and Renato Neves and Lucas Sequeira and Jorge Brito and Miguel Bravo},

url = {https://www.sciencedirect.com/science/article/pii/S0950061824028198},

doi = {10.1016/j.conbuildmat.2024.137677},

issn = {0950-0618},

year  = {2024},

date = {2024-09-01},

urldate = {2026-04-28},

journal = {Construction and Building Materials},

volume = {442},

pages = {137677},

abstract = {This study investigates the fresh-state properties and the hardened-state physical and mechanical properties of a total of 64 alkali-activated mortars incorporating different wastes as binders, such as fly ash (FA), recycled concrete (RC), recycled brick (RB), and recycled tile (RT). These waste materials were activated using sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Linear regression analysis was employed to evaluate the impact and significance of Na2O concentration (9 % or 15 %), modulus of silica (0.5 or 1), curing time in the oven (24 or 48 h), and temperature (50 °C or 70 °C) on the properties of the mortars. The results, analysed using ANOVA, indicate that all properties were affected by these parameters, except for the initial curing time in the oven for mortars made with construction and demolition waste (CDW), which showed no significant differences between periods of 24 and 48 h. Compared to mortars produced with RC, the contribution of these parameters to mechanical properties was more prominent in the mixes with RT and RB. The highest compressive strength at 28 days, for the mortars with CDW binders, was obtained by incorporating RT with 12 % of Na2O, modulus of silica of 1 and 70 °C for 48 h of initial curing, reaching 12.5 MPa. This value is 2.1 times higher than the strength obtained in mixes with RB or RC. The results also show that the performance of the mortars is highly related to the reactivity of the waste material (mortars with RT performed better) and prove that each raw material has its own optimum criterion.},

keywords = {Alkali activator, Construction and demolition waste, Geopolymer, Mechanical properties, Physical properties},

pubstate = {published},

tppubtype = {article}

}

@article{pasandin_performance_2020,

title = {Performance of hot-mix asphalt involving recycled concrete aggregates},

author = {Ana M. Rodríguez-Pasandín and Ignacio Pérez-Pérez},

url = {https://doi.org/10.1080/10298436.2018.1518525},

doi = {10.1080/10298436.2018.1518525},

issn = {1029-8436},

year  = {2020},

date = {2020-07-01},

urldate = {2026-08-06},

journal = {International Journal of Pavement Engineering},

volume = {21},

number = {9},

pages = {1044–1056},

publisher = {Taylor & Francis},

abstract = {The incorporation of recycled concrete aggregates (RCA) from construction and demolition waste (CDW) in hot-mix asphalt (HMA) could be a way to promote sustainable construction. This paper describes a laboratory study on the use of RCA in HMA for base courses in road pavements. HMA involving RCA in percentages of 0%, 5%, 10%, 20% and 30% were evaluated. To improve the moisture damage resistance of HMA made with RCA, the mixtures were cured in the oven for 4 h at a mixing temperature of 170°C, before compaction. The results indicated that the mixes made with RCA and cured for 4 h in the oven loosely fulfil the Spanish moisture damage specifications. The results also indicated that the Marshall Stability and the moisture damage resistance are substantially improved by curing the mixture in the oven. The mixtures also exhibited an adequate resistance to permanent deformation. The results from this study were highly encouraging, although HMA with RCA requires further investigation.},

keywords = {absorbed bitumen content, Construction and demolition waste, curing time, effective binder, hot-mix asphalt, moisture damage resistance, Recycled concrete aggregates},

pubstate = {published},

tppubtype = {article}

}

@article{galan_evaluation_2020,

title = {Evaluation of the Resilient Modulus of Hot-Mix Asphalt Made with Recycled Concrete Aggregates from Construction and Demolition Waste},

author = {Juan José Galán-Díaz and Luís M. Silva and Ana M. Rodríguez-Pasandín and Ignacio Pérez-Pérez},

url = {https://www.mdpi.com/2071-1050/12/20/8551},

doi = {10.3390/su12208551},

issn = {2071-1050},

year  = {2020},

date = {2020-01-01},

urldate = {2026-08-06},

journal = {Sustainability},

volume = {12},

number = {20},

pages = {8551},

publisher = {Multidisciplinary Digital Publishing Institute},

abstract = {This paper reports the influence of the percentage of recycled aggregate (RCA) from construction and demolition waste (C&DW) together with the percentage of binder (L), curing time (t) and temperature (T) of the samples on the stiffness of a hot asphalt mixture. The study was carried out using the response surface methodology (RSM). The resilient modulus was chosen to estimate the stiffness of the mixture. The percentages of RCA studied were 0% (control), 5%, 10%, 20% and 30%, whilst 3.5%, 4% and 4.5% were those chosen for the binder content. Before compacting the samples, they were left into the oven to cure. Curing time, or pretreatment time, were set at 0 (control), 2 and 4 h. The samples were subjected to temperatures of 0, 10 and 20 °C. The natural aggregate is of the hornfels type. All the specimens studied showed high stiffness at low temperatures. According to this research, temperature proved to be the most influential factor on the decrease in the resilient modulus and, conversely, the percentage of recycled aggregate is not a significant factor in the range of values studied.},

keywords = {Construction and demolition waste, hot-mix asphalt, recycled concrete aggregate, resilient modulus, response surface methodology},

pubstate = {published},

tppubtype = {article}

}

@article{galan_mechanical_2019,

title = {Mechanical Behavior of Hot-Mix Asphalt Made with Recycled Concrete Aggregates from Construction and Demolition Waste: A Design of Experiments Approach},

author = {Juan José Galán-Díaz and Luís M. Silva and Ignacio Pérez-Pérez and Ana M. Rodríguez-Pasandín},

url = {https://www.mdpi.com/2071-1050/11/13/3730},

doi = {10.3390/su11133730},

issn = {2071-1050},

year  = {2019},

date = {2019-01-01},

urldate = {2026-08-05},

journal = {Sustainability},

volume = {11},

number = {13},

pages = {3730},

publisher = {Multidisciplinary Digital Publishing Institute},

abstract = {The present work is a re-evaluation of previous research on the durability of hot-mix asphalt made with recycled concrete aggregates from construction and demolition waste (CDW) with a different approach. Response surface methodology (RSM) was used to conduct this study. The kind of natural aggregates (schist and calcite-dolomite), the recycled concrete aggregates percentage (0%, 20%, 40% and 60%) and the water saturation (0% and 100%) were the pertinent factors for this methodology. Indirect tensile stress (ITS) was determined in mixtures fabricated with 0%, 20%, 40% and 60% recycled concrete aggregates. According to the results, the ITS of the bituminous mixtures increases as the percentage of recycled concrete aggregate increases. This behavior is more significant when calcite-dolomite is used as a natural aggregate. Water saturation has the same influence in both natural aggregates. The indirect tensile strength ratio (ITSR) was calculated to evaluate the stripping potential. According to the Spanish specifications, the results suggest that the percentage of CDW that can be used for hot mixes is 17% when schist is used as natural aggregate and 14% for calcite-dolomite.},

keywords = {Construction and demolition waste, hot-mix asphalt, indirect tensile stress, recycled concrete aggregate, response surface methodology},

pubstate = {published},

tppubtype = {article}

}