Influence of recycled rubber and glass aggregates on magnesium sulfate resistance of geopolymers: Physio-mechanical properties and mechanisms
Source abstract
Abstract
Recycled rubber aggregates (RRA) and recycled glass aggregates (RGA) are sustainable alternatives to natural aggregates. However, the influences of RRA and RGA on the magnesium sulfate resistance of geopolymers remain unclear. Previous studies have focused on the influences of binder type and composition on magnesium sulfate resistance but have neglected the role of aggregates. This study bridges this gap and demonstrates the influences of RRA and RGA on the magnesium sulfate resistance of geopolymers. This study investigated the physical properties, mechanical properties and phases of FA and GBFS-based geopolymers containing 0:10 – 10:0 RRA and RGA after being exposed to 5 % MgSO 4 solution for 90 days. The results showed that compared to 100 % RGA, the 90-day length and mass of 100 % RRA increased by 50.48 and 33.22 times, respectively, and the 90-day compressive, flexural and splitting tensile strengths of 100 % RRA decreased by 65 %, 43.28 % and 56.75 %, respectively. However, the changes in length and mass of 100 % RGA were very small, and the mechanical properties even slightly increased rather than decreased. RRA + RGA showed an interval performance between 100 % RRA and 100 % RGA. The different magnesium sulfate resistance of RRA and RGA were attributed to the following mechanisms. RRA caused much higher drying shrinkage of geopolymers than RGA because the soft nature of RRA increased uncoordinated deformation, leading to micro-cracks in the matrix before magnesium sulfate exposure. The pre-existing micro-cracks served as physical transportation paths for external ions to diffuse into the interior of specimens, leading to expansive gypsum crystals formed in these micro-cracks. The accumulation of expansive gypsum crystals enlarged these micro-cracks and facilitated their propagation, leading to the expansion, cracking and degraded mechanical properties. By contrast, RGA reduced drying shrinkage due to its hard nature, which limited the availability of micro-cracks as physical transportation paths for external ions and therefore reduced the formation of expansive gypsum crystals and improved the magnesium sulfate resistance of geopolymers.
Source: expertdata · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Concrete and Cement Materials Research · Magnesium Oxide Properties and Applications · Innovative concrete reinforcement materials
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (55)
Show source-provided references
1. Innovative modeling techniques including MEP, ANN and FQ to forecast the compressive strength of geopolymer concrete modified with nanoparticles10.1007/s00521-023-08378-3 ↗
2. Prediction of concrete materials compressive strength using surrogate models10.1016/j.istruc.2022.11.002 ↗
3. Machine learning techniques and multi-scale models to evaluate the impact of silicon dioxide (SiO2) and calcium oxide (CaO) in fly ash on the compressive strength of green concrete10.1016/j.conbuildmat.2023.132604 ↗
4. Chemical and physical effects of high-volume limestone powder on sodium silicate-activated slag cement (AASC)10.1016/j.conbuildmat.2021.123257 ↗
5. A review: Reaction mechanism and strength of slag and fly ash-based alkali-activated materials10.1016/j.conbuildmat.2022.126843 ↗
6. Effect of Ca(OH)2 on shrinkage characteristics and microstructures of alkali-activated slag concrete10.1016/j.conbuildmat.2018.04.180 ↗
7. Setting behaviours and early-age microstructures of alkali-activated ground granulated blast furnace slag (GGBS) from different regions in China10.1016/j.cemconcomp.2020.103782 ↗
8. Morphology-structural change of C-A-S-H gel in blended cements10.1016/j.cemconres.2023.107156 ↗
9. Advantages and disadvantages of PVA-fibre-reinforced slag- and fly ash-blended geopolymer composites: Engineering properties and microstructure10.1016/j.conbuildmat.2022.128690 ↗
10. Investigation of effects of Portland cement fineness and alkali content on concrete plastic shrinkage cracking10.1016/j.conbuildmat.2017.03.130 ↗
11. A comparative study on shrinkage characteristics of graphene oxide (GO) and graphene nanoplatelets (GNPs) modified alkali-activated slag cement composites10.1617/s11527-021-01695-w ↗
12. Time is running out for sand
13. Synergetic recycling of waste glass and recycled aggregates in cement mortars: Physical, durability and microstructure performance10.1016/j.cemconcomp.2020.103632 ↗
14. Partial replacement of copper slag with treated crumb rubber aggregates in alkali-activated slag mortar10.1016/j.conbuildmat.2020.119468 ↗
15. Synergetic effects of recycled crumb rubber and glass cullet on the engineering properties of geopolymer mortar10.1016/j.cemconcomp.2022.104907 ↗
16. PVA fiber-reinforced geopolymer mortar made with hybrid recycled aggregates: Toward thermal insulation, lightweight and improved durability10.1016/j.jclepro.2023.139200 ↗
17. Properties and application of thixotropic cement paste backfill with molybdenum tailings10.1016/j.jclepro.2023.136169 ↗
18. Utilization of coal gangue as coarse aggregates in structural concrete10.1016/j.conbuildmat.2020.121212 ↗
19. A step towards sustainable concrete with substitution of plastic waste in concrete: Overview on mechanical, durability and microstructure analysis10.3390/cryst12070944 ↗
20. Utilization of lithium nitrate to mitigate alkali–silica reaction of architectural glass mortar: Characteristics and mechanisms10.1016/j.conbuildmat.2021.125433 ↗
21. Strengthening sandwich composites by laminating ultra-thin oriented carbon nanotube sheets at the skin/core interface10.1016/j.compositesb.2024.111496 ↗
22. Mechanical enhancement of natural-fiber-reinforced composites modified with recycled thermoset composite fillers10.1177/07316844241247896 ↗
23. Increasing strength and ductility of extruded polylactic acid matrix composites using short polyester and continuous carbon fibers10.1007/s00170-023-12887-9 ↗
24. H.E.P.D, Monitoring of Solid Waste in Hong Kong 2016, 2016. Available in https://www.wastereduction.gov.hk/sites/default/files/msw2016.pdf.
25. Experimental study of mechanical properties and durability of green concrete containing slag, waste rubber powder and recycled aggregate with artificial neural network
26. The influence of Si/Al ratio on sulfate durability of metakaolin-based geopolymer10.1016/j.conbuildmat.2020.120735 ↗
27. Durability of geopolymer materials in sodium and magnesium sulfate solutions10.1016/j.cemconres.2004.09.002 ↗
28. Microstructural examination of black seawater mixed sulfate-resistant cement concrete10.1061/JMCEE7.MTENG-15962 ↗
29. Magnesium sulfate resistance of geopolymer mortar10.1016/j.conbuildmat.2018.06.212 ↗
30. Mechanism of sulfate attack on alkali-activated slag: The role of activator composition10.1016/j.cemconres.2019.105868 ↗
31. Resistance to acid and sulfate solutions of microwave-assisted high calcium fly ash geopolymer10.1617/s11527-012-9907-1 ↗
32. Short-term improvement of ductile geopolymer composites exposed to magnesium sulfate: Mechanical properties, sorptivity, and mechanisms10.1016/j.conbuildmat.2023.133648 ↗
33. Microstructural changes in alkali activated fly ash/slag geopolymers with sulfate exposure10.1617/s11527-012-9906-2 ↗
34. Rubberized geopolymer composites: A comprehensive review10.1016/j.ceramint.2022.06.123 ↗
35. Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack10.1016/j.wasman.2009.04.002 ↗
36. Macroscopic behavior and microstructural analysis of recycled aggregate mortar bars exposed to external sulfate attack10.1016/j.cemconcomp.2023.105277 ↗
37. Durability of concrete containing recycled concrete coarse and fine aggregates and milled waste glass in magnesium sulfate environment
38. Influence of recycled concrete aggregates on the engineering and durability properties of alkali activated slag concrete10.1016/j.conbuildmat.2016.12.050 ↗
39. Sulfate and acid resistance of lithomarge-based geopolymer mortars10.1016/j.conbuildmat.2018.01.129 ↗
40. A comprehensive investigation on sulphate resistance of geopolymer recycled concrete: Macro and micro properties10.1016/j.conbuildmat.2023.133052 ↗
41. Chemical–physical–mechanical stability of MKG mortars under sulfate attacks10.1680/jadcr.19.00094 ↗
42. Sulfate resistance of hybrid fiber reinforced metakaolin geopolymer composites10.1016/j.compositesb.2019.107689 ↗
43. Porosity of recycled concrete with substitution of recycled concrete aggregate: An experimental study10.1016/S0008-8846(02)00795-0 ↗
44. Durability characteristics of slag based geopolymer concrete modified with crumb rubber10.1016/j.conbuildmat.2023.132851 ↗
45. Utilisation of steel fibres to reinforce waste glass concrete: Alkali–silica reaction, engineering properties, and 3D mesoscale modelling
46. Long-term drying shrinkage of mortar - influence of silica fume and size of fine aggregate10.1016/S0008-8846(00)00347-1 ↗
47. Influence of fly ash on the pore structure and shrinkage characteristics of metakaolin-based geopolymer pastes and mortars10.1016/j.conbuildmat.2017.05.067 ↗
48. Mitigating drying shrinkage and enhancing mechanical strength of fly ash-based geopolymer paste with functionalized MWCNTs grafted with silane coupling agent10.1016/j.cemconcomp.2023.105250 ↗
49. Effect of basalt fiber on fracture properties and drying shrinkage of alkali-activated slag with different silicate modulus10.1016/j.jmrt.2023.05.211 ↗
50. Engineering properties of PVA fibre-reinforced geopolymer mortar containing waste oyster shells10.3390/ma15197013 ↗
51. Sustainable use of recycled crumb rubbers in eco-friendly alkali activated slag mortar: Dynamic mechanical properties10.1016/j.jclepro.2018.08.306 ↗
52. Comparative environmental evaluation of aggregate production from recycled waste materials and virgin sources by LCA10.1016/j.resconrec.2016.02.009 ↗
53. Use of recycled aggregates for low carbon and cost effective concrete construction10.1016/j.jclepro.2018.04.090 ↗
54. On the acoustical performance of eco-friendly cementitious composite with recycled fine rubber particles10.1016/j.conbuildmat.2022.126830 ↗
55. A comprehensive overview about recycling rubber as fine aggregate replacement in traditional cementitious materials10.1016/j.ijsbe.2015.11.003 ↗