Study on thermo-mechanical behavior of concrete subjected to thermal cycles
By: Vidya B
.
Contributor(s): Rao, K. Srinivasa.
Publisher: Thane ACC LTD 2022Edition: Vol.96(3), Mar.Description: 32-42p.Subject(s): Civil EngineeringOnline resources: Click here
In:
Indian Concrete Journal - ICJSummary: As the use of high-strength concrete becomes common, the risk of exposing it to high temperatures also increased. The behavior of high strength concrete under elevated temperatures differs from that of normal strength concrete. When concrete is exposed to elevated temperatures, it begins to experience dehydration reactions in the hydrated cement paste, possible thermal incompatibilities between paste and aggregate and eventual physico-chemical deterioration of the aggregate. Typically, such degradation is accompanied by a decrease in the strength and weight of the concrete. Moreover, repeated thermal cycling due to fluctuating temperatures reduces the peak strength and could loosen the bond between the cement and aggregate. The thermal gradients and induced thermal stresses could trigger micro cracking, crumbling and spalling of the concrete.
Hence, an investigation on the behavior of standard and high strength concrete, exposed to thermal cycles at elevated temperatures was carried out. They were carried out on concrete specimens of age 28 days and exposed to temperatures from 100 to 400°C for 8 hours duration and subsequent air cooling for the remaining period of a day. Therefore, one thermal cycle means 8 hours heating and 16 hours cooling. Thermogravimetric analysis (TGA) has been carried out to study thermal stability of standard concrete and high strength concrete and based on this study the critical temperature of concrete is found to be 400°C. The mechanical properties studied in this work are compressive strength, split tensile strength and flexural strength. The results obtained can be useful as guidelines for fire resistant design of the structures subjected to heating and cooling cycles at elevated temperatures.
| Item type | Current location | Call number | Status | Date due | Barcode | Item holds |
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Articles Abstract Database
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School of Engineering & Technology (PG) Archieval Section | Not for loan | 2022-1986 |
As the use of high-strength concrete becomes common, the risk of exposing it to high temperatures also increased. The behavior of high strength concrete under elevated temperatures differs from that of normal strength concrete. When concrete is exposed to elevated temperatures, it begins to experience dehydration reactions in the hydrated cement paste, possible thermal incompatibilities between paste and aggregate and eventual physico-chemical deterioration of the aggregate. Typically, such degradation is accompanied by a decrease in the strength and weight of the concrete. Moreover, repeated thermal cycling due to fluctuating temperatures reduces the peak strength and could loosen the bond between the cement and aggregate. The thermal gradients and induced thermal stresses could trigger micro cracking, crumbling and spalling of the concrete.
Hence, an investigation on the behavior of standard and high strength concrete, exposed to thermal cycles at elevated temperatures was carried out. They were carried out on concrete specimens of age 28 days and exposed to temperatures from 100 to 400°C for 8 hours duration and subsequent air cooling for the remaining period of a day. Therefore, one thermal cycle means 8 hours heating and 16 hours cooling. Thermogravimetric analysis (TGA) has been carried out to study thermal stability of standard concrete and high strength concrete and based on this study the critical temperature of concrete is found to be 400°C. The mechanical properties studied in this work are compressive strength, split tensile strength and flexural strength. The results obtained can be useful as guidelines for fire resistant design of the structures subjected to heating and cooling cycles at elevated temperatures.
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