Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated Temperatures
This study examines the effect of silica fume (SF) as a partial replacement for cement to prevent strength retrogression in hardened cement paste (HCP) and mortar at elevated temperatures. An experimental procedure was conducted on 320 specimens, replacing 0, 10, 20, and 30% of the cement by weight...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-05-01
|
| Series: | Buildings |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-5309/13/5/1301 |
| _version_ | 1797600782562885632 |
|---|---|
| author | Ngaelle Dorivice Nkanpa Moffo John Mwero Zachary A. Gariy |
| author_facet | Ngaelle Dorivice Nkanpa Moffo John Mwero Zachary A. Gariy |
| author_sort | Ngaelle Dorivice Nkanpa Moffo |
| collection | DOAJ |
| description | This study examines the effect of silica fume (SF) as a partial replacement for cement to prevent strength retrogression in hardened cement paste (HCP) and mortar at elevated temperatures. An experimental procedure was conducted on 320 specimens, replacing 0, 10, 20, and 30% of the cement by weight with SF. The residual compressive strength of the specimens was evaluated at room temperature (25 °C) and at 100, 200, 300, and 400 °C for 7, 28, and 56 days. The results indicate that the addition of SF to the cement paste and mortar improves the compressive strength both at 25 °C and at temperatures up to 400 °C. That is attributed to the formation of C-S-H phases, such as tobermorite and xonotlite. Additionally, the optimal residual compressive strength was achieved by adding 30% of SF. Therefore, XRD, SEM, and EDS techniques were employed to evaluate the microstructure of HCP specimens with 30% of SF. The results show that adding SF leads to a denser microstructure and lower porosity, resulting in more durable cement paste and mortar at ambient and elevated temperatures. In conclusion, using SF as a partial replacement for cement can be an effective way of developing sustainable fire-resistant construction materials. |
| first_indexed | 2024-03-11T03:52:48Z |
| format | Article |
| id | doaj.art-7d6cefe33fe64206a8afb1eeb9664413 |
| institution | Directory Open Access Journal |
| issn | 2075-5309 |
| language | English |
| last_indexed | 2024-03-11T03:52:48Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Buildings |
| spelling | doaj.art-7d6cefe33fe64206a8afb1eeb96644132023-11-18T00:46:22ZengMDPI AGBuildings2075-53092023-05-01135130110.3390/buildings13051301Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated TemperaturesNgaelle Dorivice Nkanpa Moffo0John Mwero1Zachary A. Gariy2Department of Civil Engineering, Pan African University Institute for Basic Sciences, Technology and Innovation, Nairobi P.O. Box 62000-00200, KenyaSchool of Civil and Resource Engineering, The Technical University of Kenya, Nairobi P.O. Box 52428-00200, KenyaDepartment of Civil and Construction Engineering, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi P.O. Box 62000-00200, KenyaThis study examines the effect of silica fume (SF) as a partial replacement for cement to prevent strength retrogression in hardened cement paste (HCP) and mortar at elevated temperatures. An experimental procedure was conducted on 320 specimens, replacing 0, 10, 20, and 30% of the cement by weight with SF. The residual compressive strength of the specimens was evaluated at room temperature (25 °C) and at 100, 200, 300, and 400 °C for 7, 28, and 56 days. The results indicate that the addition of SF to the cement paste and mortar improves the compressive strength both at 25 °C and at temperatures up to 400 °C. That is attributed to the formation of C-S-H phases, such as tobermorite and xonotlite. Additionally, the optimal residual compressive strength was achieved by adding 30% of SF. Therefore, XRD, SEM, and EDS techniques were employed to evaluate the microstructure of HCP specimens with 30% of SF. The results show that adding SF leads to a denser microstructure and lower porosity, resulting in more durable cement paste and mortar at ambient and elevated temperatures. In conclusion, using SF as a partial replacement for cement can be an effective way of developing sustainable fire-resistant construction materials.https://www.mdpi.com/2075-5309/13/5/1301strength retrogressioncompressive strengthhardened cement pasteelevated temperatureSFSEM |
| spellingShingle | Ngaelle Dorivice Nkanpa Moffo John Mwero Zachary A. Gariy Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated Temperatures Buildings strength retrogression compressive strength hardened cement paste elevated temperature SF SEM |
| title | Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated Temperatures |
| title_full | Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated Temperatures |
| title_fullStr | Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated Temperatures |
| title_full_unstemmed | Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated Temperatures |
| title_short | Performance of Silica Fume on Preventing Strength Retrogression in Hardened Cement Paste and Mortar at Elevated Temperatures |
| title_sort | performance of silica fume on preventing strength retrogression in hardened cement paste and mortar at elevated temperatures |
| topic | strength retrogression compressive strength hardened cement paste elevated temperature SF SEM |
| url | https://www.mdpi.com/2075-5309/13/5/1301 |
| work_keys_str_mv | AT ngaelledorivicenkanpamoffo performanceofsilicafumeonpreventingstrengthretrogressioninhardenedcementpasteandmortaratelevatedtemperatures AT johnmwero performanceofsilicafumeonpreventingstrengthretrogressioninhardenedcementpasteandmortaratelevatedtemperatures AT zacharyagariy performanceofsilicafumeonpreventingstrengthretrogressioninhardenedcementpasteandmortaratelevatedtemperatures |