Chloride Ingress in Chemically Activated Calcined Clay-Based Cement
Chloride-laden environments pose serious durability concerns in cement based materials. This paper presents the findings of chloride ingress in chemically activated calcined Clay-Ordinary Portland Cement blended mortars. Results are also presented for compressive strength development and porosity te...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Journal of Chemistry |
| Online Access: | http://dx.doi.org/10.1155/2018/1595230 |
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| author | Joseph Mwiti Marangu Joseph Karanja Thiong’o Jackson Muthengia Wachira |
| author_facet | Joseph Mwiti Marangu Joseph Karanja Thiong’o Jackson Muthengia Wachira |
| author_sort | Joseph Mwiti Marangu |
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| description | Chloride-laden environments pose serious durability concerns in cement based materials. This paper presents the findings of chloride ingress in chemically activated calcined Clay-Ordinary Portland Cement blended mortars. Results are also presented for compressive strength development and porosity tests. Sampled clays were incinerated at a temperature of 800°C for 4 hours. The resultant calcined clay was blended with Ordinary Portland Cement (OPC) at replacement level of 35% by mass of OPC to make test cement labeled PCC35. Mortar prisms measuring 40 mm × 40 mm × 160 mm were cast using PCC35 with 0.5 M Na2SO4 solution as a chemical activator instead of water. Compressive strength was determined at 28th day of curing. As a control, OPC, Portland Pozzolana Cement (PPC), and PCC35 were similarly investigated without use of activator. After the 28th day of curing, mortar specimens were subjected to accelerated chloride ingress, porosity, compressive strength tests, and chloride profiling. Subsequently, apparent diffusion coefficients (Dapp) were estimated from solutions to Fick’s second law of diffusion. Compressive strength increased after exposure to the chloride rich media in all cement categories. Chemically activated PCC35 exhibited higher compressive strength compared to nonactivated PCC35. However, chemically activated PCC35 had the least gain in compressive strength, lower porosity, and lower chloride ingress in terms of Dapp, compared to OPC, PPC, and nonactivated PCC35. |
| format | Article |
| id | doaj-art-02cfdf7995e2438f85d51017a7840c6e |
| institution | Kabale University |
| issn | 2090-9063 2090-9071 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
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| series | Journal of Chemistry |
| spelling | doaj-art-02cfdf7995e2438f85d51017a7840c6e2025-02-03T05:47:50ZengWileyJournal of Chemistry2090-90632090-90712018-01-01201810.1155/2018/15952301595230Chloride Ingress in Chemically Activated Calcined Clay-Based CementJoseph Mwiti Marangu0Joseph Karanja Thiong’o1Jackson Muthengia Wachira2Department of Chemistry, Kenyatta University, P.O. Box 43844-00100, Nairobi, KenyaDepartment of Chemistry, Kenyatta University, P.O. Box 43844-00100, Nairobi, KenyaDepartment of Physical Sciences, University of Embu, P.O. Box 6-00100, Embu, Nairobi, KenyaChloride-laden environments pose serious durability concerns in cement based materials. This paper presents the findings of chloride ingress in chemically activated calcined Clay-Ordinary Portland Cement blended mortars. Results are also presented for compressive strength development and porosity tests. Sampled clays were incinerated at a temperature of 800°C for 4 hours. The resultant calcined clay was blended with Ordinary Portland Cement (OPC) at replacement level of 35% by mass of OPC to make test cement labeled PCC35. Mortar prisms measuring 40 mm × 40 mm × 160 mm were cast using PCC35 with 0.5 M Na2SO4 solution as a chemical activator instead of water. Compressive strength was determined at 28th day of curing. As a control, OPC, Portland Pozzolana Cement (PPC), and PCC35 were similarly investigated without use of activator. After the 28th day of curing, mortar specimens were subjected to accelerated chloride ingress, porosity, compressive strength tests, and chloride profiling. Subsequently, apparent diffusion coefficients (Dapp) were estimated from solutions to Fick’s second law of diffusion. Compressive strength increased after exposure to the chloride rich media in all cement categories. Chemically activated PCC35 exhibited higher compressive strength compared to nonactivated PCC35. However, chemically activated PCC35 had the least gain in compressive strength, lower porosity, and lower chloride ingress in terms of Dapp, compared to OPC, PPC, and nonactivated PCC35.http://dx.doi.org/10.1155/2018/1595230 |
| spellingShingle | Joseph Mwiti Marangu Joseph Karanja Thiong’o Jackson Muthengia Wachira Chloride Ingress in Chemically Activated Calcined Clay-Based Cement Journal of Chemistry |
| title | Chloride Ingress in Chemically Activated Calcined Clay-Based Cement |
| title_full | Chloride Ingress in Chemically Activated Calcined Clay-Based Cement |
| title_fullStr | Chloride Ingress in Chemically Activated Calcined Clay-Based Cement |
| title_full_unstemmed | Chloride Ingress in Chemically Activated Calcined Clay-Based Cement |
| title_short | Chloride Ingress in Chemically Activated Calcined Clay-Based Cement |
| title_sort | chloride ingress in chemically activated calcined clay based cement |
| url | http://dx.doi.org/10.1155/2018/1595230 |
| work_keys_str_mv | AT josephmwitimarangu chlorideingressinchemicallyactivatedcalcinedclaybasedcement AT josephkaranjathiongo chlorideingressinchemicallyactivatedcalcinedclaybasedcement AT jacksonmuthengiawachira chlorideingressinchemicallyactivatedcalcinedclaybasedcement |