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Concrete from Construction Solid Waste
With the development of human society and urban modernization, a large amount of construction waste is generated every year due to the demolition of buildings. The annual output of these construction wastes can reach 4 billion tons, and the output is increasing year by year. Most of these construction wastes are directly dumped or landfilled, and the recycling rate is extremely low; pollution of the environment is increasingly serious. In recent years, with the awakening of human environmental awareness, coupled with natural aggregates and cementing material in short supply, people have gradually turned their attention to this part of construction waste. Various technical means to prepare it into RCA, RFA, and RP, and recycled concrete. However, the performance of these recycled materials is generally inferior to that of natural materials.
Solutions are needed to solve the problem of a large amount of construction solid waste and a shortage of natural aggregate (coarse and fine aggregates). In this paper, simple-crushed coarse aggregate (SCRCA) and simple-crushed fine aggregate (SCRFA) were obtained by simple-crushing of construction solid waste. On this basis, SCRCA and SCRFA were treated with particle-shaping to obtain particle-shaping coarse aggregate (PSRCA) and particle-shaping fine aggregate (PSRFA), and the recycled powder (RP) produced in the process of particle-shaping was collected. Under the condition of a 1:4 cement-sand ratio, RP was used to replace cement with four substitution rates of 0, 10%, 20%, and 30%, and dry-mixed masonry mortar was prepared with 100% SCRFA, PSRFA, and river sand (RS). The basic and mechanical properties and microstructure of hydration products of dry-mixed mortar were analyzed, and the maximum substitution rate of RP was determined. Under the condition that the amount of cementitious material is 400 kg/m3 and the RP is at the maximum replacement rate, three different aggregate combinations to prepare concrete are the 100% use of SCRCA and SCRFA, PSRCA and PSRFA, and RS and natural aggregate (NCA); the workability, mechanical properties, and aggregate interface transition zone of the prepared concrete were analyzed. The results show that when the replacement rate of RP is less than 20%, it has little effect on the properties of products. The performance of PSRCA and PSRFA after treatment is better than that of SCRCA and SCRFA. Under different RP substitution rates, the performance of dry-mixed mortar prepared with PSRFA is very close to that prepared with RS. The performance of recycled concrete prepared with PSRCA and PSRFA is also very close to that of products prepared with NCA and RS. The failure morphology of PSRCA and RSRFA concrete is also similar to that of NCA and RS concrete.
2. Construction Solid Waste
After particle shaping, the performance of PSRCA and PSRFA is close to the basic performance of NCA and RS and is much higher than that of SCRCA and SCRFA.
As the replacement rate of RP increases, the performance indicators of dry-mixed masonry mortar gradually decrease. To ensure the application of products in actual projects, the maximum replacement rate of RP should not be greater than 20%.
When the RP replacement rate is 20%, the performance of the product can not only meet the requirements of use, but also reduce the amount of cement to the greatest extent, and realize the comprehensive utilization of waste resources, energy savings, and emission reduction.
In the concrete prepared with different aggregate combinations, the failure mode of SCRCA and DCRFA concrete mainly damage the interface between the old and the new mortar, and the aggregate cannot play the role of skeleton support. The damage morphology of the concrete prepared by the PSRCA and PSRFA treated by the particle-shaping technology is the same as that of the NCA and RS concrete, and the damage is mainly caused by the crushing of the aggregate.
In follow-up research, we can further study the influence of different types of aggregates on the performance of concrete, such as NCA and PSRFA, NCA and SCRFA, PSRCA and RS, PSRCA and SCRFA, etc.
The entry is from 10.3390/su13158385
- 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. Cem. Concr. Compos. 2020, 114, 103807.
- Kapoor, K.; Singh, S.; Singh, B.; Singh, P. Effect of recycled aggregates on fresh and hardened properties of self compacting concrete. Mater. Today Proc. 2020, 32, 600–607.
- Lu, W. Big data analytics to identify illegal construction waste dumping: A Hong Kong study. Resour. Conserv. Recycl. 2019, 141, 264–272.
- Guerra, B.C.; Bakchan, A.; Leite, F.; Faust, K.M. BIM-based automated construction waste estimation algorithms: The case of concrete and drywall waste streams. Waste Manag. 2019, 87, 825–832.
- Vitale, F.; Nicolella, M. Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review. Sustainability 2021, 13, 2756.
- Wu, H.; Zuo, J.; Zillante, G.; Wang, J.; Yuan, H. Status quo and future directions of construction and demolition waste research: A critical review. J. Clean. Prod. 2019, 240, 118163.
- Seror, N.; Portnov, B.A. Estimating the effectiveness of different environmental law enforcement policies on illegal C&D waste dumping in Israel. Waste Manag. 2020, 102, 241–248.
- Xiao, J.; Ma, Z.; Ding, T. Reclamation chain of waste concrete: A case study of Shanghai. Waste Manag. 2016, 48, 334–343.
- Mistri, A.; Bhattacharyya, S.K.; Dhami, N.K.; Mukherjee, A.; Barai, S.V. A review on different treatment methods for enhancing the properties of recycled aggregates for sustainable construction materials. Constr. Build. Mater. 2020, 233, 117894.
- Superti, V.; Houmani, C.; Hansmann, R.; Baur, I.; Binder, C. Strategies for a Circular Economy in the Construction and Demolition Sector: Identifying the Factors Affecting the Recommendation of Recycled Concrete. Sustainability 2021, 13, 4113.
- Koushkbaghi, M.; Alipour, P.; Tahmouresi, B.; Mohseni, E.; Saradar, A.; Sarker, P.K. Influence of different monomer ratios and recycled concrete aggregate on mechanical properties and durability of geopolymer concretes. Constr. Build. Mater. 2019, 205, 519–528.
- Li, J.; Zhou, H.; Chen, W.; Chen, Z. Mechanical Properties of a New Type Recycled Aggregate Concrete Interlocking Hollow Block Masonry. Sustainability 2021, 13, 745.
- Meng, D.; Wu, X.; Quan, H.; Zhu, C. A strength-based mix design method for recycled aggregate concrete and consequent durability performance. Constr. Build. Mater. 2021, 281, 122616.
- Yoo, D.-Y.; You, I.; Zi, G. Effects of waste liquid–crystal display glass powder and fiber geometry on the mechanical properties of ultra-high-performance concrete. Constr. Build. Mater. 2021, 266, 120938.
- Naeini, M.; Mohammadinia, A.; Arulrajah, A.; Horpibulsuk, S. Recycled Glass Blends with Recycled Concrete Aggregates in Sustainable Railway Geotechnics. Sustainablity 2021, 13, 2463.
- Thomas, C.; de Brito, J.; Cimentada, A.; Sainz-Aja, J. Macro- and micro-properties of multi-recycled aggregate concrete. J. Clean. Prod. 2020, 245, 118843.
- Bravo-German, A.; Bravo-Gómez, I.; Mesa, J.; Maury-Ramírez, A. Mechanical Properties of Concrete Using Recycled Ag-gregates Obtained from Old Paving Stones. Sustainability 2021, 13, 3044.
- Wang, R.; Yu, N.; Li, Y. Methods for improving the microstructure of recycled concrete aggregate: A review. Constr. Build. Mater. 2020, 242, 118164.
- Shah, M.C.; Gupta, K.K.; Nainwal, A.; Negi, A.; Kumar, V. Investigation of mechanical properties of concrete with natural aggregates partially replaced by recycled coarse aggregate (RCA). Mater. Today Proc. 2021.
- Hassan, R.Y.; Faroun, G.A.; Mohammed, S.K. Mechanical properties of concrete made with coarse and fine recycled aggregates. Mater. Today Proc. 2021.
- Gao, D.; Wang, F. Effects of recycled fine aggregate and steel fiber on compressive and splitting tensile properties of concrete. J. Build. Eng. 2021, 44, 102631.
- Kaarthik, M.; Maruthachalam, D. A sustainable approach of characteristic strength of concrete using recycled fine aggregate. Mater. Today Proc. 2020.
- Pacheco, J.; de Brito, J.; Chastre, C.; Evangelista, L. Experimental investigation on the variability of the main mechanical properties of concrete produced with coarse recycled concrete aggregates. Constr. Build. Mater. 2019, 201, 110–120.
- Duan, Z.; Singh, A.; Xiao, J.; Hou, S. Combined use of recycled powder and recycled coarse aggregate derived from construction and demolition waste in self-compacting concrete. Constr. Build. Mater. 2020, 254, 119323.
- Boudali, S.; Abdulsalam, B.; Rafiean, A.; Poncet, S.; Soliman, A.; ElSafty, A. Influence of Fine Recycled Concrete Powder on the Compressive Strength of Self-Compacting Concrete (SCC) Using Artificial Neural Network. Sustainablity 2021, 13, 3111.
- Gupta, T.; Siddique, S.; Sharma, R.K.; Chaudhary, S. Behaviour of waste rubber powder and hybrid rubber concrete in aggressive environment. Constr. Build. Mater. 2019, 217, 283–291.
- Gebremariam, A.T.; Vahidi, A.; Di Maio, F.; Moreno-Juez, J.; Vegas-Ramiro, I.; Łagosz, A.; Mróz, R.; Rem, P. Comprehensive study on the most sustainable concrete design made of recycled concrete, glass and mineral wool from C&D wastes. Constr. Build. Mater. 2021, 273, 121697.
- Huo, W.; Zhu, Z.; Chen, W.; Zhang, J.; Kang, Z.; Pu, S.; Wan, Y. Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers. Constr. Build. Mater. 2021, 292, 123264.
- Liu, D.; Quan, X.; Zhou, L.; Huang, Q.; Wang, C. Utilization of waste concrete powder with different particle size as absorbents for SO2 reduction. Constr. Build. Mater. 2021, 266, 121005.