Impact of Elevated Temperature on Properties of Limestone Concrete
Adel A. El-Kurdi1, Ali Abdel-Hakam2, Mohamed M. El-Gohary3
1Adel A. El-Kurdi, Professor, Department of Structural Engineering, Alexandria University, Egypt.
2Ali Abdel-Hakam, Professor, Department of Structural Engineering, Alexandria University, Egypt.
3Mohamed M. El-Gohary, Department of Structural Engineering, Alexandria University, Egypt.
Manuscript received on 10 September 2014 | Revised Manuscript received on 20 September 2014 | Manuscript Published on 30 September 2014 | PP: 1-9 | Volume-4 Issue-4, September 2014 | Retrieval Number: C1756084314/14©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Limestone is normally less expensive than portland cement and can cost effectively replace a part of the powder content in most concretes. For this suppose, the scope of this work is to provide experimental data on the residual mechanical and physical properties of concrete containing limestone powder as a replacement or additive of cement content by mass subjected to heat. For this goal, five mixtures were casted, one as a control mixture and the others were with 10 and 15% limestone fines as a replacement and additive of cement content by mass. Reductions in both compressive and flexural strength results along with the extent of weight loss were examined. The mineralogy in unheated and preheated concrete at 20, 200, 400 and 600ºC was identified by means of thermogravimetry (TGA/DTG). Finally the scanning electron microscope (SEM) was done to study the microstructure of the hardened concrete. According to the results, limestone fines had a considerable effect on the properties of the concrete. The results indicated that, the residual compressive and flexural strength of 10 and15 % limestone fines as additive to cement content by mass are generally higher than those of convention concrete. In other words, elevated fire temperature is more damaging to the traditional concrete compared with additive limestone concrete. It has been established that limestone replacement causes reduce the compressive and flexural strength due to the dilution effect. The presence of limestone fines generally reduces the weight loss of heated concrete. TGA/DTG curves of unheated and preheated specimens can be used to estimate the degree of temperature which may the concrete exposed in accidental building fire as a practical part. Based on SEM images, no obvious cracks in limestone concrete whether as limestone replacement or additive up to 600ºC and the CaCO3 clearly observed without decomposition.
Keywords: Fire Resistance, Limestone Fines, (TGA/DTG) And SEM.
Scope of the Article: Concrete Structures