Next Article in Journal
Flexural Performance of Chopped Basalt Fiber Reinforced Concrete Beams
Previous Article in Journal
Physico-Chemical Properties of Sewage Sludge Ash and Its Influence on the Chemical Shrinkage of Cement Pastes
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Proceeding Paper

Increasing the Pozzolanic Reactivity of Recovered CDW Cement Stone by Mechanical Activation †

Institute of Raw Material Preparation and Environmental Processing, University of Miskolc, Egyetemváros, 3515 Miskolc, Hungary
Author to whom correspondence should be addressed.
Presented at the 10th MATBUD’2023 Scientific-Technical Conference “Building Materials Engineering and Innovative Sustainable Materials”, Cracow, Poland, 19–21 April 2023.
Mater. Proc. 2023, 13(1), 27;
Published: 15 February 2023
(This article belongs to the Proceedings of 10th MATBUD’2023 Scientific-Technical Conference)


The study focuses on enhancing the reactivity of the fine size fraction of construction and demolition waste (CDW) by mechanical activation in a stirred media mill. Systematic measurements were carried out to monitor the change in cement stone reactivity. The fine size fraction of CDW (<200 µm) was milled in a stirred media mill for 1, 3, 5, and 10 min. The dispersion characteristics (particle size distribution, specific surface area (SSA)) of the mechanically activated CDW powder were determined using a laser particle size analyzer. Changes in the structure of the mechanically activated CDW powder particles were determined by Fourier transform infrared spectroscopy (FTIR) measurements. The effect of the mechanical activation on the pozzolanic reactivity of CDW powder was measured by lime sorption test and compressive strength measurements. The results clearly show that Portland cement can be replaced with mechanically activated CDW powder; however, increasing its amount decreases the strength. Furthermore, the grinding fineness significantly influenced the pozzolanic reactivity of the mechanically activated CDW powder, and thus the strength of the specimens. The CDW powder milled for 10 min had 51% more lime uptake than the initial CDW sample, and the specimen strength at the age of 7 days was 23% higher using ground CDW powder than using initial CDW at a 20% cement replacement ratio.

1. Introduction

The construction sector can be considered the largest resource user and waste producer in the world. About 3 billion tons of construction and demolition waste are generated annually in the world [1], while in the European Union (EU), 37.1% of total waste (approximately 800 million tons) was generated in the construction industry in 2020 [2], and this trend is constantly increasing. For this reason, the reuse and recycling of construction and demolition waste (CDW) is a key point not only for increasing resource efficiency, but also for reducing the use of large amounts of primary materials, energy consumption, and waste generation.
Despite the fact that many ways of utilizing CDW are known [3,4,5,6,7,8], there are many problems that prevent their large-scale use as a substitute for primary raw materials [9]. One of the largest components of CDW waste is concrete waste (other than excavated soil), approximately 70–80% of whose volume consists of fine and coarse aggregates, causing continuous depletion of natural resources [7]. Fine and coarse aggregates can be extracted from concrete waste using different processes (crushing, magnetic separation and sieving process), which can then be used as recycled concrete aggregates in different structures [7,10,11,12,13,14]. At the same time, the fine powder fraction (<150 µm) mainly from the cement stone part of concrete can also be used in recycled concrete or geopolymer [15,16,17]. However, in order to increase the reactivity of the CDW particles, milling may also be necessary, which can be performed in various mills (planetary mill [18], ball mill [17,18,19], vibratory mill [18], and stirred media mill [20]). The advantages and disadvantages of CDW powder fineness were summarized in a study by Tang et al. [21].
The aim of the research work is to increase the pozzolanic reactivity of the CDW powder fraction using a high energy-density mill (stirred media mill) and to study the relationships between its reactivity, structural characteristics, and the properties of the produced cement stone.

2. Materials and Methods

The base materials for the experiments were CDW with particle size <63 mm from Mento Ltd. (Bodrogkeresztúr, Hungary) and Portland cement (CEM II/A-S 42.5 R). As a first step, the CDW sample was crushed with a jaw crusher with a gap size of 20 mm. The fine fraction (<200 µm) was removed with sieving, and the 20-8 mm fraction was used in a Deval apparatus for autogenous milling for 60 min. This way, due to the abrasion of the CDW, a higher amount of cement stone could be obtained. The fine products of the previous steps were used as feed for the mechanical activation. The mineralogical composition of CDW was determined with a Bruker D8 Advance X-ray powder diffractometer (XRD) (Cu-Kα radiation, 40 kV, 40 mA) in parallel beam geometry (Göbel-mirror), as can be seen in Table 1. The high amount of quartz and carbonates come from the sand and hydrated cement. Mechanical activation was carried out in a stirred media mill with 530 cm3 volume, using ZS type, Ø 1–1.2 mm ceramic beads and 5 m/s circumferential velocity. Both the material and grinding media filling ratio was 0.7. The applied milling times were 1, 3, 5 and 10 min. The 0 min milling refers to the pre-processed sample that was not mechanically activated in the stirred media mill.
The particle size distributions and SSA of the mechanically activated samples were analyzed with a HORIBA LA950-V2 laser particle size analyzer. The pozzolanic reactivity was assessed based on the lime sorption test carried out according to the MSZ 4706-2:1998 standard. For the structural analysis, a Jasco FTIR-4200 analyzer equipped with a diamond ATR was used, with 4 cm−1 spectral resolution. The spectra were recorded between 400–4000 cm−1 and baseline-corrected.
To further test the reactivity of the mechanically activated CDW cement, samples were prepared to examine the possibility of Portland cement replacement using the mechanically activated CDW cement stones. In the specimens, the Portland cement was replaced with 0%, 10%, 20% and 30% mechanically activated cement stone, and a 0.33 water-cement ratio was applied to all mixtures. The uniaxial compressive strength of the 20 × 20 mm cubical specimens was measured with an SZF-1 type hydraulic press.

3. Results and Discussion

3.1. Mechanical Activation of CDW

3.1.1. Particle Size, SSA

The effect of mechanical activation on the particle size and geometric SSA of CDW is shown in Table 2. Milling resulted in a decrease in the particle size of CDW, while the specific surface area increased. After 10 min of milling, the specific surface area of CDW increased by 33%, but at the same time, no significant decrease in particle size was observed. This can presumably be attributed to the high quartz content (Figure 1), which hindered the efficiency of the milling.

3.1.2. FTIR

The FTIR spectra of the cement and ground CDW can be seen in Figure 1. In the case of the raw cement spectrum, the transmittance bands at 1421, 874 and 713 cm−1 can be assigned to v3, v2, and v4 stretching modes of CO32−, respectively. The weak band at 1124 cm−1 is generally the indication of Si–O–Si stretching vibrations and the band at 521 cm−1 corresponds to the Si–O deformation vibrations of the siliceous phases [22,23].
For the CDW samples, some new bands could also be observed compared to the cement sample. The broad band between ~3500–2800 cm−1 corresponds to the stretching O–H, and the weak band at 1614 cm−1 to the O–H bending mode, indicating the presence of a small amount of structural and weakly bound water in the samples. The bands centered between 1420–1450 cm−1 and at 875 cm−1 are associated with the calcite and other carbonate species. The broad band of 1010–1030 cm−1 originates from the asymmetric stretching vibrations of the C–S–H structure that was originally formed in the cementitious matrix. The bands at 795 and 695 cm−1 show the presence of quartz [20,24]. Comparing the spectra of the ground CDW samples, no significant changes occurred in the structure with the different milling times. After 3 min or longer mechanical activation, the intensity of the C–S–H band slightly increased and broadened, indicating the possible amorphization of the material.

3.2. CDW Reactivity

3.2.1. Pozzolanic Reactivity

Lime adsorption is an indicative measure of hydraulic/pozzolanic reactivity. The results of the lime sorption tests are shown in Table 3. Based on the Table 3, it can be stated that the SSA and CaO uptake values followed a similar trend after the mechanical activation: the increased SSA significantly increased the amount of adsorbed CaO. The lime uptake of CDW increased from the initial 126.9 mg CaO/g solid material to 192.1 mg CaO/g solid material. Thus, as a result of a 33% increase in SSA, the CaO uptake increased by over 50%.
Figure 2 illustrates the volume change (swelling) during the reaction between CDW and lime. It can be clearly seen that the ground CDWs had a larger volume than the original at the end of the lime sorption test (after 30 days), indicating a greater degree of reactivity.

3.2.2. Compressive Strength

Figure 3 shows the effect of CDW dosage and powder fineness on the compressive strength of the cement-based specimens. Based on the results, it can be concluded that the replacement of cement with CDW reduced the strength of the specimens. This correlates well with the results of other studies [16,20,25,26]. However, it is also seen that the ground CDWs showed better results compared to the unground (0 min) sample, at 20 and 30% cement replacement. Furthermore, specimens prepared using CDW ground for 5 and 10 min gave similar results at 20 and 30% cement replacement, which can be explained by their similar particle size distribution (Table 2). Generally, no clear correlation can be observed between the grinding time and replacement ratio. This can be explained by the heterogeneity and the high quartz content of the recycled cement stone [16,27].

3.2.3. FTIR

Figure 4 shows the FTIR spectra of the samples in the case of 0 min CDW dosing at different ratios. Based on Figure 4, it can be stated that the intensity of some bands decreased as a result of CDW dosing. The intensity of the bands around 1420 cm−1 and 874 cm−1, which can be attributed to calcite and other carbonates, decreased to the greatest extent. In addition, the intensity of the band at 3640 cm−1 (which indicates the presence of portlandite (Ca(OH)2) [28]) and the S–O stretching vibration of [SO4]2− at 1150–1100 cm−1 also decreased with the addition of CDW.
Figure 5 shows the FTIR spectra of the samples containing CDW with different powder fineness, produced with 20% cement replacement. Figure 5 shows that the same bands appeared for each sample. The intensity of the bands at 1420 cm−1 and 874 cm−1 belonging to calcite and other carbonates increased with the fineness of the CDW. The broad band at around 3400 cm−1 is attributed to the symmetric stretching vibration of the H2O molecule, while the sharp, narrow band at 3640 cm−1 can be assigned to O–H stretching vibration (portlandite) [26,28], which showed a slight decrease by 10 min milling. The band at around 960 cm−1 implies the Si–O stretching vibrations, indicating a wide range of C–S–H. The band at 960 cm−1 is assigned to Si–O stretching vibrations, which is the result of the C–S–H phase with Ca/Si ≈ 2. When it reaches 1080 cm−1, it indicates the formation of silica gel [29]. Higher intensity C–S–H related bands were observed with longer CDW cement stone milling times, indicating the effectiveness of mechanical activation.

4. Conclusions

Based on the results, the following conclusions can be drawn:
  • The increased specific surface area due to mechanical activation improved the pozzolanic reactivity of CDW dust (50% better CaO uptake after 10 min of milling).
  • The use of CDW dust as a cement substitute reduced the strength of cement-based materials.
  • The use of mechanically activated CDW led to a lower strength reduction than the unactivated sample.
  • As a result, cement can be replaced with mechanically activated CDW in remarkable quantities (20 or 30%); thus it can be used primarily in areas where high structural performance is not required.
  • No significant changes occurred in the structure due to MA. However, the increase in intensity of the C–S–H band indicates the possible surface amorphization of the particles.

Author Contributions

R.S.: conceptualization, methodology, investigation, data curation, writing—original draft preparation, and supervision. M.S.: investigation, writing—review and editing, data curation, formal analysis, and visualization. M.A.: writing—original draft preparation, formal analysis, data curation, and visualization. G.M.: conceptualization, methodology, formal analysis, writing—review and editing, and supervision. All authors have read and agreed to the published version of the manuscript.


Publication cost of this paper was covered with funds of the Polish National Agency for Academic Exchange (NAWA): “MATBUD’2023–Developing international scientific cooperation in the field of building materials engineering” BPI/WTP/2021/1/00002, MATBUD’2023.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.


The research work was performed in the Centre of Excellence in Sustainable Natural Resource Management at the Faculty of Earth Science and Engineering, University of Miskolc. Project no. 2019-2.1.7-ERA-NET-2022-00051 has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the 2019-2.1.7-ERA-NET funding scheme. The authors thank the Institute of Mining and Geotechnical Engineering of the University of Miskolc for their help during the mechanical strength tests and the Institute of Mineralogy and Geology for the XRD analysis of CDW.

Conflicts of Interest

The authors declare no conflict of interest.


  1. Akhtar, A.; Sarmah, A.K. Construction and demolition waste generation and properties of recycled aggregate concrete: A global perspective. J. Cleaner Product. 2018, 186, 262–281. [Google Scholar] [CrossRef]
  2. Eurostat, Waste Statistic–European Commission. 2022. Available online: (accessed on 12 October 2022).
  3. Gedik, A. A review on the evaluation of the potential utilization of construction and demolition waste in hot mix asphalt pavements. Res. Con. Rec. 2020, 161, 104956. [Google Scholar] [CrossRef]
  4. Li, L.; Liu, Q.; Huang, T.; Peng, W. Mineralization and utilization of CO2 in construction and demolition wastes recycling for building materials: A systematic review of recycled concrete aggregate and recycled hardened cement powder. Sep. Pur. Technol. 2022, 298, 121512. [Google Scholar] [CrossRef]
  5. Bordoloi, S.; Afolayan, O.D.; Ng, C.W.W. Feasibility of construction demolition waste for unexplored geotechnical and geo-environmental applications—A review. Constr. Build. Mater. 2022, 356, 129230. [Google Scholar] [CrossRef]
  6. Tavakoli Mehrjardi, G.; Azizi, A.; Haji-Aziz, A.; Asdollafardi, G. Evaluating and improving the construction and demolition waste technical properties to use in road construction. Trans. Geotech. 2020, 23, 100349. [Google Scholar] [CrossRef]
  7. Mohammed, M.S.; ElKady, H.; Abdel-Gawwad, H.A. Utilization of construction and demolition waste and synthetic aggregates. J. Build. Eng. 2021, 43, 103207. [Google Scholar] [CrossRef]
  8. Khodaei, H.; Olson, C.; Patino, D.; Rico, J.; Jin, Q.; Boateng, A. Multi-objective utilization of wood waste recycled from construction and demolition (C&D): Products and characterization. Waste Man. 2022, 149, 228–238. [Google Scholar] [CrossRef]
  9. Luciano, A.; Cutaia, L.; Altamura, P.; Penalvo, E. Critical issues hindering a widespread construction and demolition waste (CDW) recycling practice in EU countries and actions to undertake: The stakeholder’s perspective. Sust. Chem. Pharm. 2022, 29, 100745. [Google Scholar] [CrossRef]
  10. Kumar, R. Influence of recycled coarse aggregate derived from construction and demolition waste (CDW) on abrasion resistance of pavement concrete. Constr. Build. Mater. 2017, 142, 248–255. [Google Scholar] [CrossRef]
  11. Thomas, C.; Setién, J.; Polanco, J.A. Structural recycled aggregate concrete made with precast wastes. Construct. Build. Mater. 2016, 114, 536–546. [Google Scholar] [CrossRef]
  12. López Gayarre, F.; Suárez González, J.; Blanco Viñuela, R.; López-Colina Pérez, C.; Serrano López, M.A. Use of recycled mixed aggregates in floor blocks manufacturing. J. Clean. Prod. 2017, 167, 713–722. [Google Scholar] [CrossRef]
  13. Plaza, P.; Sáez del Bosque, I.F.; Frías, M.; Sánchez de Rojas, M.I.; Medina, C. Use of recycled coarse and fine aggregates in structural eco-concretes. Physical and mechanical properties and CO2 emissions. Constr. Build. Mater. 2021, 285, 122926. [Google Scholar] [CrossRef]
  14. Tam, V.W.Y.; Soomro, M.; Evangelista, A.C.J. A review of recycled aggregate in concrete applications (2000–2017). Constr. Build. Mater. 2018, 172, 272–292. [Google Scholar] [CrossRef]
  15. Braga, M.; de Brito, J.; Veiga, R. Incorporation of fine concrete aggregates in mortars. Constr. Build. Mater. 2012, 36, 960–968. [Google Scholar] [CrossRef]
  16. Moreno-Juez, J.; Vegas, I.J.; Frías Rojas, M.; Vigil de la Villa, R.; Guede-Vázquez, E. Laboratory-scale study and semi-industrial validation of viability of inorganic CDW fine fractions as SCMs in blended cements. Constr. Build. Mater. 2021, 271, 121823. [Google Scholar] [CrossRef]
  17. Tan, J.; Cizer, Ö.; De Vlieger, J.; Dan, H.; Li, J. Impacts of milling duration on construction and demolition waste (CDW) based precursor and resulting geopolymer: Reactivity, geopolymerization and sustainability. Res. Con. Rec. 2022, 184, 106433. [Google Scholar] [CrossRef]
  18. Fediuk, R.S.; Ibragimov, R.A.; Lesovik, V.S.; Pak, A.A.; Krylov, V.V.; Poleschuk, M.M.; Stoyushko, N.Y.; Gladkova, N.A. Processing equipment for grinding of building powders. IOP Conf. Ser. Mater. Sci. Eng. 2018, 327, 042029. [Google Scholar] [CrossRef]
  19. Li, S.; Li, Q.; Zhao, X.; Luo, J.; Gao, S.; Yue, G.; Su, D. Experimental Study on the Preparation of Recycled Admixtures by Using Construction and Demolition Waste. Materials 2019, 12, 1678. [Google Scholar] [CrossRef] [Green Version]
  20. Mucsi, G.; Halyag Papné, N.; Ulsen, C.; Figueiredo, P.O.; Kristály, F. Mechanical Activation of Construction and Demolition Waste in Order to Improve Its Pozzolanic Reactivity. ACS Sustain. Chem. Eng. 2021, 9, 3416–3427. [Google Scholar] [CrossRef]
  21. Tang, Q.; Ma, Z.; Wu, H.; Wang, W. The utilization of eco-friendly recycled powder from concrete and brick waste in new concrete: A critical review. Cement Concr. Compos. 2020, 114, 103807. [Google Scholar] [CrossRef]
  22. Amor, F.; Diouri, A.; Ellouzi, I.; Ouanji, F. Development of Zn-Al-Ti mixed oxides-modified cement phases for surface photocatalytic performance. Case Stud. Constr. Mater. 2018, 9, e00209. [Google Scholar] [CrossRef]
  23. Cho, J.; Waetzig, G.R.; Udayakantha, M.; Hong, C.Y.; Banerjee, S. Incorporation of Hydroxyethylcellulose-Functionalized Halloysite as a Means of Decreasing the Thermal Conductivity of Oilwell Cement. Sci. Rep. 2018, 8, 16149. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  24. Cristelo, N.; Fernández-Jiménez, A.; Vieira, C.; Miranda, T.; Palomo, Á. Stabilisation of construction and demolition waste with a high fines content using alkali activated fly ash. Constr. Build Mater. 2018, 170, 26–39. [Google Scholar] [CrossRef]
  25. Pešta, J.; Ženíšek, M.; Kočí, V.; Pavlů, T. Environmental perspectives of recycled concrete powder as cement replacement. In Special Concrete and Composites 2020: Proceedings of the 17th International Conference, Lísek, Czech Republic, 14–15 October 2020; AIP Publishing LLC: Melville, NY, USA, 2021; Volume 2322, p. 020028. [Google Scholar] [CrossRef]
  26. Lu, B.; Shi, C.; Zhang, J.; Wang, J. Effects of carbonated hardened cement paste powder on hydration and microstructure of Portland cement. Constr. Build. Mater. 2018, 186, 699–708. [Google Scholar] [CrossRef]
  27. Monasterio, M.; Caneda-Martínez, L.; Vegas, I.; Frías, M. Progress in the influence of recycled construction and demolition mineral-based blends on the physical–mechanical behaviour of ternary cementitious matrices. Constr. Build. Mater. 2022, 344, 128169. [Google Scholar] [CrossRef]
  28. Horgnies, M.; Chen, J.J.; Bouillon, C. Overview about the use of Fourier transform infrared spectroscopy to study cementitious materials. WIT Trans. Eng. Sci. 2013, 77, 251–262. [Google Scholar] [CrossRef] [Green Version]
  29. Pan, X.; Shi, C.; Hu, X.; Ou, Z. Effects of CO2 surface treatment on strength and permeability of one-day-aged cement mortar. Constr. Build. Mater. 2017, 154, 1087–1095. [Google Scholar] [CrossRef]
Figure 1. The FTIR spectra of the cement and ground CDW samples.
Figure 1. The FTIR spectra of the cement and ground CDW samples.
Materproc 13 00027 g001
Figure 2. CDW samples after the lime sorption test (from left to right: 0 min, 1 min, 3 min, 5 min and 10 min).
Figure 2. CDW samples after the lime sorption test (from left to right: 0 min, 1 min, 3 min, 5 min and 10 min).
Materproc 13 00027 g002
Figure 3. Results of compressive strength measurements.
Figure 3. Results of compressive strength measurements.
Materproc 13 00027 g003
Figure 4. FTIR spectra of samples with different CDW content.
Figure 4. FTIR spectra of samples with different CDW content.
Materproc 13 00027 g004
Figure 5. The FT-IR spectra of specimens (cement replacement with 20% CDW).
Figure 5. The FT-IR spectra of specimens (cement replacement with 20% CDW).
Materproc 13 00027 g005
Table 1. Mineralogical composition of CDW (wt. %).
Table 1. Mineralogical composition of CDW (wt. %).
Phase NameRaw CDW
Muscovite 2M14.0
Chlorite IIb0.6
Table 2. The characteristic particle size and SSA values of the ground cement stones.
Table 2. The characteristic particle size and SSA values of the ground cement stones.
Milling Time, minx10, µmx50, µmx80, µmSSA, cm2/cm3
Table 3. Lime adsorption of CDWs.
Table 3. Lime adsorption of CDWs.
SSA of CDW (cm2/cm3)∑Adsorbed CaO (mg/g)
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Szabó, R.; Szűcs, M.; Ambrus, M.; Mucsi, G. Increasing the Pozzolanic Reactivity of Recovered CDW Cement Stone by Mechanical Activation. Mater. Proc. 2023, 13, 27.

AMA Style

Szabó R, Szűcs M, Ambrus M, Mucsi G. Increasing the Pozzolanic Reactivity of Recovered CDW Cement Stone by Mechanical Activation. Materials Proceedings. 2023; 13(1):27.

Chicago/Turabian Style

Szabó, Roland, Máté Szűcs, Mária Ambrus, and Gábor Mucsi. 2023. "Increasing the Pozzolanic Reactivity of Recovered CDW Cement Stone by Mechanical Activation" Materials Proceedings 13, no. 1: 27.

Article Metrics

Back to TopTop