Large quantities of Construction and Demolition Waste (C&DW) are produced every year, and recycling has become the preferred method for managing concrete waste. In this context, studying the influence of the production process on the properties of recycled concrete aggregates (RCA) is an important step toward a more circular construction industry. In this study, the influence of an innovative multi-step water washing treatment on RCA and Recycled Mixed Aggregates (RMA) is investigated. Washed and unwashed recycled aggregates, produced from waste originating from a single demolition project, were characterized. The particle size distribution, Hardened Cement Paste Content (HCPC), water absorption, resistance to fragmentation, and morphology of the recycled aggregates were measured and analyzed. The results show that the water washing treatment significantly improves the quality of the aggregates by reducing fine content, floating contaminants, HCPC, and water absorption. This effect is more pronounced for RCA than for RMA.
Delvoie, S., Zhao, Z., Michel, F. and Courard, L. (2019) Market Analysis of Recycled Sands and Aggregates in Northwest Europe: Drivers and Barriers. IOP Conference Series : Earth and Environmental Science , 225, Article 012055. https://doi.org/10.1088/1755-1315/225/1/012055
Petek Gursel, A., Masanet, E., Horvath, A. and Stadel, A. (2014) Life-Cycle Inventory Analysis of Concrete Production: A Critical Review. Cement and Concrete Composites , 51, 38-48. https://doi.org/10.1016/j.cemconcomp.2014.03.005
Sri Ravindrarajah, R., Loo, Y.H. and Tam, C.T. (1987) Recycled Concrete as Fine and Coarse Aggregates in Concrete. Magazine of Concrete Research , 39, 214-220. https://doi.org/10.1680/macr.1987.39.141.214
Ong, K.C.G. and Ravindrarajah Sri, R. Mechanical Properties and Fracture Energy of Recycled-Aggregate Concretes. https://scholarbank.nus.edu.sg/handle/10635/74242
Coelho, A. and de Brito, J. (2011) Economic Analysis of Conventional versus Selective Demolition—A Case Study. Resources , Conservation and Recycling , 55, 382-392. https://doi.org/10.1016/j.resconrec.2010.11.003
Fleischer, W. and Ruby, M. (1999) Recycled Aggregates from Old Concrete Highway Pavements. Thomas Telford.
Silva, R.V., de Brito, J. and Dhir, R.K. (2017) Availability and Processing of Recycled Aggregates within the Construction and Demolition Supply Chain: A Review. Journal of Cleaner Production , 143, 598-614. https://doi.org/10.1016/j.jclepro.2016.12.070
Delvoie, S., Zhao, Z.F., Michel, F. and Courard, L. (2018) State of the Art on Recycling Techniques for the Production of Recycled Sands and Aggregates from Construction and Demolition Wastes. http://hdl.handle.net/2268/229811
Lippiatt, N.R. and Bourgeois, F.S. (2014) Recycling-Oriented Investigation of Local Porosity Changes in Microwave Heated-concrete. KONA Powder and Particle Journal , 31, 247-264. https://doi.org/10.14356/kona.2014016
Guo, Y., Zhang, J., Chen, G. and Xie, Z. (2014) Compressive Behaviour of Concrete Structures Incorporating Recycled Concrete Aggregates, Rubber Crumb and Reinforced with Steel Fibre, Subjected to Elevated Temperatures. Journal of Cleaner Production , 72, 193-203. https://doi.org/10.1016/j.jclepro.2014.02.036
Rashwan, M.S. and AbouRizk, S. (1997) The Properties of Recycled Concrete. Concrete International , 19, 56-60.
Silva, R.V., de Brito, J. and Dhir, R.K. (2016) Establishing a Relationship between Modulus of Elasticity and Compressive Strength of Recycled Aggregate Concrete. Journal of Cleaner Production , 112, 2171-2186. https://doi.org/10.1016/j.jclepro.2015.10.064
Zhao, Z., Courard, L., Groslambert, S., Jehin, T., Léonard, A. and Xiao, J. (2020) Use of Recycled Concrete Aggregates from Precast Block for the Production of New Building Blocks: An Industrial Scale Study. Resources , Conservation and Recycling , 157, Article 104786. https://doi.org/10.1016/j.resconrec.2020.104786
Hansen, T.C. and Boegh, E. (1985) Elasticity and Drying Shrinkage Concrete of Recycled Aggregate. Journal of the American Concrete Institute , 82, 648-652. https://doi.org/10.14359/10374
He, H., Stroeven, P., Stroeven, M. and Sluys, L.J. (2012) Influence of Particle Packing on Elastic Properties of Concrete. Magazine of Concrete Research , 64, 163-175. https://doi.org/10.1680/macr.10.00163
Khatib, J.M. (2005) Properties of Concrete Incorporating Fine Recycled Aggregate. Cement and Concrete Research , 35, 763-769. https://doi.org/10.1016/j.cemconres.2004.06.017
de Juan, M.S. and Gutiérrez, P.A. (2009) Study on the Influence of Attached Mortar Content on the Properties of Recycled Concrete Aggregate. Construction and Building Materials , 23, 872-877. https://doi.org/10.1016/j.conbuildmat.2008.04.012
Dhir, R., Paine, K. and Dyer, T. (2004) Recycling Construction and Demolition Wastes in Concrete. Concrete , 38, 25-28.
dos Santos, J.R., Branco, F. and de Brito, J. (2004) Mechanical Properties of Concrete with Coarse Recycled Aggregates. Structural Engineering International , 14, 213-215. https://doi.org/10.2749/101686604777963900
Tam, V.W. and Tam, C.M. (2008) Reuse of Construction and Demolition Waste in Housing Developments. Nova Science Publishers.
Zhao, Z., Remond, S., Damidot, D. and Xu, W. (2013) Influence of Hardened Cement Paste Content on the Water Absorption of Fine Recycled Concrete Aggregates. Journal of Sustainable Cement - Based Materials , 2, 186-203. https://doi.org/10.1080/21650373.2013.812942
Akbarnezhad, A., Ong, K.C.G., Tam, C.T. and Zhang, M.H. (2013) Effects of the Parent Concrete Properties and Crushing Procedure on the Properties of Coarse Recycled Concrete Aggregates. Journal of Materials in Civil Engineering , 25, 1795-1802. https://doi.org/10.1061/(asce)mt.1943-5533.0000789
Padmini, A.K., Ramamurthy, K. and Mathews, M.S. (2009) Influence of Parent Concrete on the Properties of Recycled Aggregate Concrete. Construction and Building Materials , 23, 829-836. https://doi.org/10.1016/j.conbuildmat.2008.03.006
Ghorbani, S., Sharifi, S., Ghorbani, S., Tam, V.W., de Brito, J. and Kurda, R. (2019) Effect of Crushed Concrete Waste’s Maximum Size as Partial Replacement of Natural Coarse Aggregate on the Mechanical and Durability Properties of Concrete. Resources , Conservation and Recycling , 149, 664-673. https://doi.org/10.1016/j.resconrec.2019.06.030
Vázquez, E. and Marí, A. (2006) Microstructure Analysis of Hardened Recycled Aggregate Concrete. Magazine of Concrete Research , 58, 683-690. https://doi.org/10.1680/macr.2006.58.10.683
Hansen, T.C. (1986) Recycled Aggregates and Recycled Aggregate Concrete Second State-of-the-Art Report Developments 1945-1985. Materials and Structures , 19, 201-246. https://doi.org/10.1007/bf02472036
Zhao, Z., Courard, L., Michel, F., Remond, S. and Damidot, D. (2018) Influence of Granular Fraction and Origin of Recycled Concrete Aggregates on Their Properties. European Journal of Environmental and Civil Engineering , 22, 1457-1467. https://doi.org/10.1080/19648189.2017.1304281
Florea, M.V.A. and Brouwers, H.J.H. (2013) Corrigendum to ‘Properties of Various Size Fractions of Crushed Concrete Related to Process Conditions and Re-Use’ [Cement and Concrete Research 52 (2013) 11-21]. Cement and Concrete Research , 53, Article 278. https://doi.org/10.1016/j.cemconres.2013.10.008
Nagataki, S., Gokce, A., Saeki, T. and Hisada, M. (2004) Assessment of Recycling Process Induced Damage Sensitivity of Recycled Concrete Aggregates. Cement and Concrete Research , 34, 965-971. https://doi.org/10.1016/j.cemconres.2003.11.008
Hubert, J., Zhao, Z., Michel, F. and Courard, L. (2023) Effect of Crushing Method on the Properties of Produced Recycled Concrete Aggregates. Buildings , 13, Article 2217. https://doi.org/10.3390/buildings13092217
Etxeberria, M., Vázquez, E., Marí, A. and Barra, M. (2007) Influence of Amount of Recycled Coarse Aggregates and Production Process on Properties of Recycled Aggregate Concrete. Cement and Concrete Research , 37, 735-742. https://doi.org/10.1016/j.cemconres.2007.02.002
Tam, V.W.Y., Soomro, M. and Evangelista, A.C.J. (2021) Quality Improvement of Recycled Concrete Aggregate by Removal of Residual Mortar: A Comprehensive Review of Approaches Adopted. Construction and Building Materials , 288, Article 123066. https://doi.org/10.1016/j.conbuildmat.2021.123066
Abbas, A., Fathifazl, G., Fournier, B., Isgor, O.B., Zavadil, R., Razaqpur, A.G., et al . (2009) Quantification of the Residual Mortar Content in Recycled Concrete Aggregates by Image Analysis. Materials Characterization , 60, 716-728. https://doi.org/10.1016/j.matchar.2009.01.010
Etxeberria, M., Konoiko, M., Garcia, C. and Perez, M.Á. (2022) Water-Washed Fine and Coarse Recycled Aggregates for Real Scale Concretes Production in Barcelona. Sustainability , 14, Article 708. https://doi.org/10.3390/su14020708
Bayraktar, O.Y., Kaplan, G. and Benli, A. (2022) The Effect of Recycled Fine Aggregates Treated as Washed, Less Washed and Unwashed on the Mechanical and Durability Characteristics of Concrete under Mgso4 and Freeze-Thaw Cycles. Journal of Building Engineering , 48, Article 103924. https://doi.org/10.1016/j.jobe.2021.103924
CEN (2002) EN 933-11. Tests for Geometrical Properties of Aggregates—Part 11: Classification Test for the Constituents of Coarse Recycled Aggregate.
CEN (2012) NBN EN 933-1 Tests for Geometrical Properties of Aggregates—Part 1: Determination of Particle Size Distribution-Sieving Method.
CEN (2022) NBN EN 1097-6. Tests for Mechanical and Physical Properties of Aggregates—Part 6: Determination of Particle Density and Water Absorption.
CEN (2020) EN 1097-2. Tests for Mechanical and Physical Properties of Aggregates—Part 2: Methods for the Determination of Resistance to Fragmentation.
CEN (2012) EN 933-3. Tests for Geometrical Properties of Aggregates—Part 3: Determination of Particle Shape-Flakiness Index.
Abbas, A., Fathifazl, G., Burkan Isgor, O., Razaqpur, A.G., Fournier, B. and Foo, S. (2008) Proposed Method for Determining the Residual Mortar Content of Recycled Concrete Aggregates. Journal of ASTM International , 5, 1-12. https://doi.org/10.1520/jai101087
CEN (2014) NBN EN 206 Concrete-Specification, Performance, Production and Conformity.
NBN (2024) NBN B 15-001. Concrete—Specification, Performance, Production and Conformity—National Addendum to NBN EN 206:2013+A2:2021.