Quality Improvement of Recycled Concrete Aggregate by Accelerated Carbonation under Different Pressure

Abstract

Due to the presence of old mortar (OM) and interfacial transition zone (ITZ), recycled concrete aggregate (RCA) is inferior to natural aggregate (NA). The purpose of this paper was to study the effect of accelerated carbonation on the macro-properties and micro-properties of RCA under different pressure (0.05, 0.15, 0.30 MPa). The macro-property tests included colour change, apparent density, water absorption, and crushing value of RCA. The micro-property tests included scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), and Vickers micro-hardness (VMH). The results showed that the change trends of apparent density, water absorption, and crushing value of RCA displayed exponential relationships as pressure increasing, with the optimum pressure of 0.30 MPa. SEM images indicated that the calcite caused by the hydration products in RCA and the Ca(OH)₂ derived from saturated lime water improved the properties of RCA; as the apparent density increased, the water absorption and crushing value decreased. The results of XRD and TG-DSC indicated that, as the pressure increased, the masses of Ca(OH)₂ in carbonated RCA gradually decreased, while those of CaCO₃ gradually increased, which demonstrated that the carbonation degree gradually increased. Besides, ITZ-2 was the weakest phase in RCA, but its improvement degree of VMH by accelerated carbonation was higher than that of OM. However, RCA was not completely carbonated, but only carbonated in a certain depth after 24 h accelerated carbonation.

Keywords

recycled concrete aggregate / treatment method / accelerated carbonation / interfacial transition zone / saturated lime water / calcite

References

[1] Tam V W Y, Soomro M, Evangelista A C J. A Review of Recycled Aggregate in Concrete Applications (2000–2017)[J]. Constr. Build. Mater., 2018, 172: 272-292.

[2] Ouyang K, Shi C J, Chu H Q, et al. An Overview on the Efficiency of Different Pretreatment Techniques for Recycled Concrete Aggregate[J]. J. Clean. Prod., 2020, 263: 121 264.

[3] Guo H, Shi C J, Guan X M, et al. Durability of Recycled Aggregate Concrete - A Review[J]. Cem. Concr. Compos., 2018, 89: 251-259.

[4] Kisku N, Joshi H, Ansari M, et al. A Critical Review and Assessment for Usage of Recycled Aggregate as Sustainable Construction Material[J]. Constr. Build. Mater., 2017, 131: 721-740.

[5] Yue Y C, Zhou Y W, Xing F, et al. An Industrial Applicable Method to Improve the Properties of Recycled Aggregate Concrete by Incorporating Nano-Silica and Micro-CaCO₃[J]. J. Clean. Prod., 2020, 259: 120 920.

[6] Katz A. Treatments for the Improvement of Recycled Aggregate[J]. J. Mater. Civ. Eng., 2004, 16(6): 597-603.

[7] Kang H C, Kee S H. Improving the Quality of Mixed Recycled Coarse Aggregates from Construction and Demolition Waste Using Heavy Media Separation with Fe₃O₄ Suspension[J]. Adv. Mater. Sci. Eng., 2017, 2017: 1-12.

[8] Akbarnezhad A, Ong K C G, Tam C T, et al. Effects of the Parent Concrete Properties and Crushing Procedure on the Properties of Coarse Recycled Concrete Aggregates[J]. J. Mater. Civ. Eng., 2013, 25(12): 1795-1802.

[9] Ulsen C, Tseng E, Angulo S C, et al. Concrete Aggregates Properties Crushed by Jaw and Impact Secondary Crushing[J]. J. Mater. Res. Technol., 2019, 8(1): 494-502.

[10] Pedro D, de Brito J, Evangelista L. Performance of Concrete Made with Aggregates Recycled from Precasting Industry Waste: Influence of the Crushing Process[J]. Mater. Struct., 2015, 48(12): 3965-3978.

[11] Yonezawa T, Kamiyama Y, Yanagibashi K, et al. A Study on a Technology for Producing High Quality Recycled Coarse Aggregate[J]. J. Soc. Mater. Sci., Jpn., 2001, 50(8): 835-842.

[12] Tam V W Y, Tam C M, Le K N. Removal of Cement Mortar Remains from Recycled Aggregate Using Pre-soaking Approaches[J]. Resour. Conserv. Recy., 2007, 50(1): 82-101.

[13] Wang L, Wang J L, Qian X, et al. An Environmentally Friendly Method to Improve the Quality of Recycled Concrete Aggregates[J]. Constr. Build. Mater., 2017, 144: 432-441.

[14] Saravanakumar P, Abhiram K, Manoj B. Properties of Treated Recycled Aggregates and Its Influence on Concrete Strength Characteristics[J]. Constr. Build. Mater., 2016, 111: 611-617.

[15] Bui N K, Satomi T, Takahashi H. Mechanical Properties of Concrete Containing 100% Treated Coarse Recycled Concrete Aggregate[J]. Constr. Build. Mater., 2018, 163: 496-507.

[16] Kou S C, Poon C S. Properties of Concrete Prepared with PVA-Impregnated Recycled Concrete Aggregates[J]. Cem. Concr. Compos., 2010, 32(8): 649-654.

[17] Kong D Y, Lei T, Zheng J J, et al. Effect and Mechanism of Surface-Coating Pozzalanics Materials Around Aggregate on Properties and ITZ Microstructure of Recycled Aggregate Concrete[J]. Constr. Build. Mater., 2010, 24(5): 701-708.

[18] Singh L P, Bisht V, Aswathy M S, et al. Studies on Performance Enhancement of Recycled Aggregate by Incorporating Bio and Nano Materials[J]. Constr. Build. Mater., 2018, 181: 217-226.

[19] Wu C R, Hong Z Q, Zhang J L, et al. Pore Size Distribution and ITZ Performance of Mortars Prepared with Different Bio-Deposition Approaches for the Treatment of Recycled Concrete Aggregate[J]. Cem. Concr. Compos., 2020, 111: 103 631.

[20] Zhan B J, Xuan D X, Poon C S, et al. Characterization of Interfacial Transition Zone in Concrete Prepared with Carbonated Modeled Recycled Concrete Aggregates[J]. Cem. Concr. Res., 2020, 136: 106 175.

[21] Ryu J S. Improvement on Strength and Impermeability of Recycled Concrete Made from Crushed Concrete Coarse Aggregate[J]. J. Mater. Sci. Lett., 2002, 21: 1565-1567.

[22] Tam V W Y, Gao X F, Tam C M. Microstructural Analysis of Recycled Aggregate Concrete Produced from Two-Stage Mixing Approach[J]. Cem. Concr. Res., 2005, 35(6): 1195-1203.

[23] Everaert M, Stein R, Michaux S, et al. Microwave Radiation as a Pre-Treatment for Standard and Innovative Fragmentation Techniques in Concrete Recycling[J]. Materials, 2019, 12(3): 488

[24] Bru K, Touzé S, Bourgeois F, et al. Assessment of a Microwave-Assisted Recycling Process for the Recovery of High-Quality Aggregates from Concrete Waste[J]. Int. J. Miner. Process., 2014, 126: 90-98.

[25] Touzé S, Bru K, Ménard Y, et al. Electrical Fragmentation Applied to the Recycling of Concrete Waste - Effect on Aggregate Liberation[J]. Int. J. Miner. Process., 2017, 158: 68-75.

[26] Santha Kumar G, Minocha A K. Studies on Thermo-Chemical Treatment of Recycled Concrete Fine Aggregates for Use in Concrete[J]. J. Mater. Cycles Waste Manage., 2018, 20(1): 469-480.

[27] Kim H S, Kim J M, Kim B. Quality Improvement of Recycled Fine Aggregate Using Steel Ball with the Help of Acid Treatment[J]. J. Mater. Cycles Waste Manage., 2018, 20(2): 754-765.

[28] Song I H, Ryou J S. Hybrid Techniques for Quality Improvement of Recycled Fine Aggregate[J]. Constr. Build. Mater., 2014, 72: 56-64.

[29] Xuan D X, Zhan B J, Poon C S. Durability of Recycled Aggregate Concrete Prepared with Carbonated Recycled Concrete Aggregates[J]. Cem. Concr. Compos., 2017, 84: 214-221.

[30] Yaowarat T, Horpibulsuk S, Arulrajah A, et al. Compressive and Flexural Strength of Polyvinyl Alcohol-Modified Pavement Concrete Using Recycled Concrete Aggregates[J]. J. Mater. Civ. Eng., 2018, 30(4): 04 018 046

[31] Ouyang X W, Wang L Q, Xu S D, et al. Surface Characterization of Carbonated Recycled Concrete Fines and Its Effect on the Rheology, Hydration and Strength Development of Cement Paste[J]. Cem. Concr. Compos., 2020, 114: 103 809.

[32] Liang C F, Pan B H, Ma Z M, et al. Utilization of CO2 Curing to Enhance the Properties of Recycled Aggregate and Prepared Concrete: A Review[J]. Cem. Concr. Compos., 2020, 105: 103 446.

[33] Zhan B J, Poon C S, Liu Q, et al. Experimental Study on CO₂ Curing for Enhancement of Recycled Aggregate Properties[J]. Constr. Build. Mater., 2014, 67: 3-7.

[34] Li L, Xiao J Z, Xuan D X, et al. Effect of Carbonation of Modeled Recycled Coarse Aggregate on the Mechanical Properties of Modeled Recycled Aggregate Concrete[J]. Cem. Concr. Compos., 2018, 89: 169-180.

[35] Luo S R, Ye S C, Xiao J Z, et al. Carbonated Recycled Coarse Aggregate and Uniaxial Compressive Stress-Strain Relation of Recycled Aggregate Concrete[J]. Constr. Build. Mater., 2018, 188: 956-965.

[36] Ding Y H, Wu J, Xu P, et al. Treatment Methods for the Quality Improvement of Recycled Concrete Aggregate (RCA) - A Review[J]. J. Wuhan Univ. Technol.-Mater. Sci. Ed., 2021, 36(1): 77-92.

[37] Seifan M, Berenjian A. Application of Microbially Induced Calcium Carbonate Precipitation in Designing Bio Self-Healing Concrete[J]. World J. Microb. Biot., 2018, 34(11): 168

[38] Choi H, Inoue M, Sengoku R. Change in Crystal Polymorphism of CaCO₃ Generated in Cementitious Material Under Various pH Conditions[J]. Constr. Build. Mater., 2018, 188: 1-8.

[39] Miyazaki T, Arii T, Shirosaki Y. Control of Crystalline Phase and Morphology of Calcium Carbonate by Electrolysis: Effects of Current and Temperature[J]. Ceram. Int., 2019, 45(11): 14039-14044.

[40] Liu B J, Qin J L, Shi J Y, et al. New Perspectives on Utilization of CO₂ Sequestration Technologies in Cement-Based Materials[J]. Constr. Build. Mater., 2021, 272: 121 660.

[41] Pu Y H, Li L, Wang Q Y, et al. Accelerated Carbonation Technology for Enhanced Treatment of Recycled Concrete Aggregates: A State-of-the-art Review[J]. Constr. Build. Mater., 2021, 282: 122 671.

[42] Shi C J, Wu Z M, Cao Z J, et al. Performance of Mortar Prepared with Recycled Concrete Aggregate Enhanced by CO₂ and Pozzolan Slurry[J]. Cem. Concr. Compos., 2018, 86: 130-138.

[43] Fang X L, Zhan B J, Poon C S. Enhancement of Recycled Aggregates and Concrete by Combined Treatment of Spraying Ca²⁺ Rich Waste-water and Flow-Through Carbonation[J]. Constr. Build. Mater., 2021, 277: 122 202.

[44] Wu J Y, Zhang Y S, Zhu P H, et al. Mechanical Properties and ITZ Microstructure of Recycled Aggregate Concrete Using Carbonated Recycled Coarse Aggregate[J]. J. Wuhan Univ. Technol.-Mater. Sci. Ed., 2018, 33(3): 648-653.