Effect of Nano-TiO2 on Capillary Water Absorption of Recycled Aggregate Concrete
Source abstract
Abstract
To improve the durability performance of recycled aggregate concrete in actual use, this paper uses nano-TiO2-modified recycled coarse aggregate to study, through experiments, the effects of nano-TiO2 on the pore distribution of recycled coarse aggregate concrete after freeze–thaw. The capillary-water-absorption law was used as the evaluation index. The recycled coarse aggregate concrete was prepared with different contents of nano-TiO2, and changes in the 24 h capillary water absorption and porosity of the recycled aggregate concrete after freeze–thaw cycles were analysed. With the help of high-resolution image recognition and binary-image-processing technology, the pore distribution of the recycled aggregate concrete before and after freeze–thaw cycles was obtained. Through the analysis of the water-absorption data at different times, the initial capillary-water-absorption rate, S1, is obtained. The capillary water absorption of recycled aggregate concrete is reacted with S1, and the initial capillary-water-absorption prediction model of nano-TiO2 recycled aggregate concrete under freeze–thaw cycles is established. The results show that under the action of freeze–thaw cycles, the capillary water absorption of recycled coarse aggregate concrete increases with the increase in the RCA substitution rate and decreases with the increase in nano-TiO2 content. After 150 freeze–thaw cycles, the cumulative water absorption and porosity of RC25-NT1.2 decreased by 25.52% and 14.57%, respectively, compared with the test block without nanomaterials. It was found that nano-TiO2 has a prominent role in modifying recycled aggregate concrete. Nano-TiO2 can reduce the cumulative water absorption and porosity of recycled aggregate concrete and alleviate the negative impact of the recycled coarse aggregate on capillary water absorption of concrete after freeze–thaw cycles. It was observed by scanning electron microscopy that a large amount of C–S–H gel was produced inside the concrete mixed with nano-TiO2, which bonded the internal pores and cracks to form a dense structure.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Recycled Aggregate Concrete Performance · Innovative concrete reinforcement materials · Concrete and Cement Materials Research
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, China
State Key Laboratory for Health and Safety of Bridge Structures, Wuhan 430034, China
School of Public Policy and Management, Tsinghua University, Beijing 100084, China
High-Tech Research and Development Center, Ministry of Science and Technology, Beijing 100044, China
Funding
National Natural Science Foundation of China · the State Key Laboratory of Bridge Structure Health and Safety · Hubei Universities and Colleges · Hubei University of Technology
References (36)
Show source-provided references
1. Chemical recycling and use of various types of concrete waste: A review10.1016/j.jclepro.2020.124785 ↗
2. A review of life cycle assessment of recycled aggregate concrete10.1016/j.conbuildmat.2019.03.078 ↗
3. Makul, N., Fediuk, R., Amran, M., Zeyad, A.M., Murali, G., Vatin, N., and Vasilev, Y. (2021). Use of recycled concrete aggregates in production of green cement-based concrete composites: A review. Crystals, 11.10.3390/cryst11030232 ↗
4. Al Ajmani, H., Suleiman, F., Abuzayed, I., and Tamimi, A. (2019). Evaluation of concrete strength made with recycled aggregate. Buildings, 9.10.3390/buildings9030056 ↗
5. Strength and stiffness of concrete with recycled concrete aggregates10.1016/j.conbuildmat.2017.07.015 ↗
6. Methods for improving the microstructure of recycled concrete aggregate: A review10.1016/j.conbuildmat.2020.118164 ↗
7. Influence of freeze-thaw cycles on capillary absorption and chloride penetration into concrete10.1016/j.cemconres.2017.05.018 ↗
8. Unlocking the role of pores in chloride permeability of recycled concrete: A multiscale and a statistical investigation10.1016/j.cemconcomp.2021.104320 ↗
9. A review on recycled concrete aggregates (RCA) characteristics to promote RCA utilization in developing sustainable recycled aggregate concrete (RAC)10.1080/19648189.2021.1946721 ↗
10. Mitigation of the negative effects of recycled aggregate water absorption in concrete technology10.1016/j.conbuildmat.2016.12.132 ↗
11. Li, H., Zhang, Y., and Guo, H. (2021). Numerical Simulation of the Effect of Freeze–Thaw Cycles on the Durability of Concrete in a Salt Frost Environment. Coatings, 11.10.3390/coatings11101198 ↗
12. Effects of the incorporation of recycled aggregate in the durability of the concrete submitted to freeze-thaw cycles10.1016/j.conbuildmat.2017.12.076 ↗
13. Junak, J., and Sicakova, A. (2017). Effect of surface modifications of recycled concrete aggregate on concrete properties. Buildings, 8.10.3390/buildings8010002 ↗
14. Influence of different treatment methods on the mechanical behavior of recycled aggregate concrete: A comparative study10.1016/j.cemconcomp.2019.103398 ↗
15. Freezing and thawing cycles: Effect on recycled aggregate concrete including slag10.1080/19397038.2021.1886374 ↗
16. Santana Rangel, C., Amario, M., Pepe, M., Martinelli, E., and Toledo Filho, R.D. (2020). Durability of structural recycled aggregate concrete subjected to Freeze-Thaw cycles. Sustainability, 12.10.3390/su12166475 ↗
17. Effect of Air Entraining Agent on Capillary Water Absorption of Mortar Before and After Freeze-Thaw Cycles
18. Effect of incorporating blast furnace slag and natural pozzolana on compressive strength and capillary water absorption of concrete10.1016/j.proeng.2015.06.145 ↗
19. Nano-SiO2 contribution to mechanical, durability, fresh and microstructural characteristics of concrete: A review10.1016/j.conbuildmat.2018.05.266 ↗
20. Bautista-Gutierrez, K.P., Herrera-May, A.L., Santamaría-López, J.M., Honorato-Moreno, A., and Zamora-Castro, S.A. (2019). Recent progress in nanomaterials for modern concrete infrastructure: Advantages and challenges. Materials, 12.10.3390/ma12213548 ↗
21. Concrete blocks nano-modified with zinc oxide (ZnO) for photocatalytic paving: Performance comparison with titanium dioxide (TiO2)10.1016/j.conbuildmat.2020.119120 ↗
22. Li, G., Cui, H., Zhou, J., and Hu, W. (2019). Improvements of nano-TiO2 on the long-term chloride resistance of concrete with polymer coatings. Coatings, 9.10.3390/coatings9050323 ↗
23. Liu, F., Zhang, T., Luo, T., Zhou, M., Ma, W., and Zhang, K. (2019). The effects of Nano-SiO2 and Nano-TiO2 addition on the durability and deterioration of concrete subject to freezing and thawing cycles. Materials, 12.10.3390/ma12213608 ↗
24. Pore structure and chloride diffusivity of recycled aggregate concrete with nano-SiO2 and nano-TiO210.1016/j.conbuildmat.2017.05.168 ↗
25. Hydration and properties of nano-TiO2 blended cement composites10.1016/j.cemconcomp.2012.02.009 ↗
26. (2009). Standard for test methods of long-term performance and durability of ordinary concrete (Standard No. GB/T 50082-2009).
27. Effect of recycled coarse aggregate on the new interfacial transition zone concrete10.1016/j.conbuildmat.2018.09.180 ↗
28. Memon, S.A., Bekzhanova, Z., and Murzakarimova, A. (2022). A Review of Improvement of Interfacial Transition Zone and Adherent Mortar in Recycled Concrete Aggregate. Buildings, 12.10.3390/buildings12101600 ↗
29. Effects of nano-TiO2 on the toughness and durability of cement-based material
30. Influences of nano-TiO2 on the properties of cement-based materials: Hydration and drying shrinkage10.1016/j.conbuildmat.2015.02.003 ↗
31. Effect of nano-TiO2 on C–S–H phase distribution within Portland cement paste10.1007/s10853-020-04847-5 ↗
32. Influence of partial replacement TiO2 nanoparticles on the compressive and flexural strength of ordinary cement mortar
33. Effect of nano-titanium dioxide on mechanical and electrical properties and microstructure of reactive powder concrete10.1088/2053-1591/aa87db ↗
34. Optimizing the content of nano-SiO2, nano-TiO2 and nano-CaCO3 in Portland cement paste by response surface methodology10.1016/j.jobe.2020.102073 ↗
35. Capillary water absorption characteristics of recycled concrete in Freeze-Thaw environment10.1155/2020/1620914 ↗
36. Prediction of mechanical properties of green concrete incorporating waste foundry sand based on gene expression programming10.1016/j.jhazmat.2019.121322 ↗