* Metadata of the article in the English version is available in full starting in 2016.

Determination of the fire resistance of prestressed concrete slab with unbonded reinforcement

UDC [614.841.332+539.422.22]:693.56
Authors Polevoda Ivan Ivanovich, PhD in Technical Sciences, Associate Professor
Zaynudinova Natal'ya Vladimirovna
Abstract Purpose. The article is dedicated to features of determination of the fire resistance of prestressed concrete slab with unbonded reinforcement.
Methods. The fire test concrete slabs with unbonded reinforcement of the fire resistance.
Findings. The probability of occurrence of fragile destruction of prestressed concrete slab with unbonded reinforcement of the compressed zone is considered. The fire resistance limit of prestressed concrete slab with unbonded reinforcement and critical temperature for reinforcement are determined. Inverse problem on determination of fire resistance defined the critical temperature for reinforcement. The schemes of slabs destruction are reviewed.
Application field of research. The obtained experimental study data could be used in calculation and design of prestressed concrete slab with unbonded reinforcement.
Conclusions. The scheme of destruction of test samples meet the standard scheme of destruction of prestressed concrete slabs with unbonded reinforcement, while the rate of destruction is much higher and the critical temperature of reinforcement is much lower. For prestressed concrete slab with unbonded reinforcement by fire effect is typical strong brittle fracture in the compressed construction zone. As the brittle fracture can’t be avoided in view of the specific of structures, it is necessary to apply the constructive solutions for the protection of the protective concrete layer.
Keywords fire resistance, fire resistance limits, temperature regime, brittle failure, humidity
  References
1. Polevoda I.I., Zainudinova N.V., Chaichic N.I. Rezul'taty ispytanija na ognestojkost' zhelezobetonnyh predvaritel'no naprjazhennyh plit bez sceplenija armatury s betonom [The results of the fire test concrete slabs with unbonded reinforcement of the fire resistance]. Vestnik Komandno-inzhenernogo instituta MChS Respubliki Belarus'. 2016. No. 1 (23). Pp. 37-44. (rus).
2. Technical Code of Good Practice 45-2.2.02-110-2008 Building constructions. Calculation procedures of fire resistance limits. The full-text information retrieval system «StroyDOKUMENT». Electronic text data and programs (700 Mb). Minsk, RUE «Stroytechnorm», 2007. 1 electronic optical disc (CD-ROM). (rus).
3. Rekomendacii po zashhite betonnyh i zhelezobetonnyh konstrukcij ot hrupkogo razrushenija pri pozhare [Recommendations for the protection of concrete and reinforced concrete constructions against brittle failure in case of fire]. Moscow : Stroyizdat, 1979. 30 p..
4. Technical Code of Good Practice EN 1992–1–2–2009 Plain concrete structures. Affirmed 01.01.2010. Minsk : The Ministry of Architecture and Building, 2010. 86 p. (rus).
5. Standard of Republic of Belarus 1544-2005’ Constructional normal – weight concretes. Specifications. Affirmed 01.07.2005. Minsk : Gosstandart, 2005. 20 p. (rus).
6. Mihaylov V.V. Predvaritel'no-naprjazhennye zhelezobetonnye konstrukcii (teorija, raschet, podbor sechenij) [Prestressed concrete construction (theory, calculation, dimensioning)]. Moscow, 1978. 383 p. (rus).
7. Standard of Republic of Belarus 1168-2012 Precast concrete products. Hollow core slabs. Affirmed 20.04.2012. Minsk: Gosstandart, 2012. 58 p. (rus).
8. Standard of Republic of Belarus 10138-3-2009 Prestressed wire-rope reinforcement for reinforced concrete structures. Specifications. Affirmed 01.01.2010. Minsk: Gosstandart, 2012. 13 p. (rus).
9. Building norms of Republic of Belarus 5.03.01-02 Plain and reinforced concrete structures. Affirmed 01.07.2003. Minsk: The Ministry of Architecture and Building, 2003. 144 p. (rus).
10. Interstate Standard 30247.0-94. Elements of building constructions. Fire resistance tests methods. General reguirements. Affirmed 01.10.1998. Minsk : Minsktipproekt, 1998. 12 p. (rus).
11. Interstate Standard 30247.1-94 Elements of building constructions. Fire resistance tests methods. Loadbearing and separating constructions Affirmed 01.10.1998. Minsk: Minsktipproekt, 1998. 7 p. (rus).