Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete Pavements
Waste and recycled materials have recently been used in the construction industry to comply with the principles of circular economy and sustainable development. The aim of this paper is to examine the potentials of solidified wastewater treatment sludge (SWWTS) as a supplementary cementitious materi...
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MDPI AG
2022-07-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/14/4919 |
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| author | Ognjen Govedarica Marina Aškrabić Milica Hadnađev-Kostić Tatjana Vulić Branislava Lekić Vladana Rajaković-Ognjanović Dimitrije Zakić |
| author_facet | Ognjen Govedarica Marina Aškrabić Milica Hadnađev-Kostić Tatjana Vulić Branislava Lekić Vladana Rajaković-Ognjanović Dimitrije Zakić |
| author_sort | Ognjen Govedarica |
| collection | DOAJ |
| description | Waste and recycled materials have recently been used in the construction industry to comply with the principles of circular economy and sustainable development. The aim of this paper is to examine the potentials of solidified wastewater treatment sludge (SWWTS) as a supplementary cementitious material (SCM) in the production of lightweight pervious concrete pavers (LWPCP) suitable for pedestrian trails and rooftops (green) that comply with EU standards. Detailed characterization of SWWTS was performed, in order to understand its properties related to application as SCM, which led to the conclusion that it may be applied only as a filler, having 89.5% of Ca(OH)<sub>2</sub>. After thorough characterization, LWPCP samples were prepared and testing of physical and mechanical properties was conducted. The research showed that partial replacement of cement with SWWTS led to the decrease of all mechanical properties, ranging between 3.91 and 5.81 MPa for compressive strength and 0.97 to 1.23 MPa for flexural strength. However, all of the investigated mixtures showed a value higher than 3.5 MPa, which was defined as the lowest compressive strength in the range of pervious concrete properties. The addition of SWWTS led to a slight decrease in bulk density of the mixtures and an increase in water absorption. This could be explained by the reduction in hydration products that would fill in the micropores of the matrix, since SWWTS showed no pozzolanic reactivity. Pore sizes that prevail in the tested binder matrices are in accordance with the results measured on ordinary pervious concrete (the largest fraction of pores had a diameter between 0.02 and 0.2 μm). Low thermal conductivity nominates produced pavers as potential rooftop elements. |
| first_indexed | 2024-03-09T06:17:22Z |
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| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T06:17:22Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-fa245ce5be834deab2972f238514efd92023-12-03T11:52:13ZengMDPI AGMaterials1996-19442022-07-011514491910.3390/ma15144919Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete PavementsOgnjen Govedarica0Marina Aškrabić1Milica Hadnađev-Kostić2Tatjana Vulić3Branislava Lekić4Vladana Rajaković-Ognjanović5Dimitrije Zakić6Faculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Beograd, SerbiaFaculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Beograd, SerbiaDepartment of Basic Engineering Disciplines, Faculty of Technology, University of Novi Sad, 21000 Novi Sad, SerbiaDepartment of Basic Engineering Disciplines, Faculty of Technology, University of Novi Sad, 21000 Novi Sad, SerbiaFaculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Beograd, SerbiaFaculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Beograd, SerbiaFaculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Beograd, SerbiaWaste and recycled materials have recently been used in the construction industry to comply with the principles of circular economy and sustainable development. The aim of this paper is to examine the potentials of solidified wastewater treatment sludge (SWWTS) as a supplementary cementitious material (SCM) in the production of lightweight pervious concrete pavers (LWPCP) suitable for pedestrian trails and rooftops (green) that comply with EU standards. Detailed characterization of SWWTS was performed, in order to understand its properties related to application as SCM, which led to the conclusion that it may be applied only as a filler, having 89.5% of Ca(OH)<sub>2</sub>. After thorough characterization, LWPCP samples were prepared and testing of physical and mechanical properties was conducted. The research showed that partial replacement of cement with SWWTS led to the decrease of all mechanical properties, ranging between 3.91 and 5.81 MPa for compressive strength and 0.97 to 1.23 MPa for flexural strength. However, all of the investigated mixtures showed a value higher than 3.5 MPa, which was defined as the lowest compressive strength in the range of pervious concrete properties. The addition of SWWTS led to a slight decrease in bulk density of the mixtures and an increase in water absorption. This could be explained by the reduction in hydration products that would fill in the micropores of the matrix, since SWWTS showed no pozzolanic reactivity. Pore sizes that prevail in the tested binder matrices are in accordance with the results measured on ordinary pervious concrete (the largest fraction of pores had a diameter between 0.02 and 0.2 μm). Low thermal conductivity nominates produced pavers as potential rooftop elements.https://www.mdpi.com/1996-1944/15/14/4919wastewater treatment sludgesolidificationpervious pavement concretesupplementary cementitious materialslightweight concrete |
| spellingShingle | Ognjen Govedarica Marina Aškrabić Milica Hadnađev-Kostić Tatjana Vulić Branislava Lekić Vladana Rajaković-Ognjanović Dimitrije Zakić Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete Pavements Materials wastewater treatment sludge solidification pervious pavement concrete supplementary cementitious materials lightweight concrete |
| title | Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete Pavements |
| title_full | Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete Pavements |
| title_fullStr | Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete Pavements |
| title_full_unstemmed | Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete Pavements |
| title_short | Evaluation of Solidified Wastewater Treatment Sludge as a Potential SCM in Pervious Concrete Pavements |
| title_sort | evaluation of solidified wastewater treatment sludge as a potential scm in pervious concrete pavements |
| topic | wastewater treatment sludge solidification pervious pavement concrete supplementary cementitious materials lightweight concrete |
| url | https://www.mdpi.com/1996-1944/15/14/4919 |
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