YANGIN DURUMUNDA MAKRO BETON NUMUNELERDE MEYDANA GELEN TERMO-MEKANİK GERİLMELERİN BETON DAYANIMINA ETKİSİ

Yıl 2018, Cilt: 19 Sayı: 2, 53 - 63, 28.12.2018

Ataman Haksever

Öz

Reolojik araştırma çalışmaları, yangın durumunda, malzeme
davranışını belirlemek için küçük boyutlu numuneler kullanmakta ve deney
sonuçlarından yapı elemanlarının yangın davranışını belirlemede kullanılacak
malzeme davranış kanunlarını saptamaktadır. Bununla beraber, bilindiği üzere,
beton makro elemanlarda ısı ve kütle taşınımları önemli ölçüde farklı fazlarda
meydana gelmektedir. Küçük numunelerden elde edilmiş olan deney sonuçlarının,
yapı elemanlarına tatbikinin geçerliliği, şimdiye kadar araştırılmamış bir fenomen
teşkil etmektedir. Böyle bir araştırma çalışması ilk defa SFB ye ait (Özel
Araştırma Alanı : Braunschweig Teknik Üniversitesi’nde yapı elemanlarının yangın
davranışı üzerine özel araştırma aktivitesi) A ve B3 alt araştırma projelerinin
yakın çalışması sonucunda gerçekleştirilmiştir. Bu çalışmada ortaya konan
reolojik araştırma sonuçları, beton yapı elemanlarının gerçekçi yangın durumunu
belirlemede yeni bir araştırma kavramına öncelik edebilir. İleride amaca
yönelik araştırma çalışmalarında yangın durumunda yapı elemanlarının gerçek
davranışını, basit matematik-reolojik bağıntılarla belirlemek mümkün olacaktır.

Anahtar Kelimeler

Yangın durumu, betonarme, makro numuneler, yangın dayanımı, sünme, reoloji

EFFECTS OF THERMO-MECHANICAL STRESSES ON THE STRENGTH BEHAVIOR OF CONCRETE IN MACRO SPECIMENS IN FIRE CASE

Öz

Rheological research works investigate for fire
case the material behavior of small specimens and derive from the test results
material laws to determine the behavior of structural elements due to fire
exposure. However, as it is known, the heat and mass transport processes can
significantly happen in different phases in macro concrete elements. Besides,
in case of a fire, different heating rates occur in the cross section of
structural elements. The validity of the transferred test results from small
test specimens to the material behavior of structural elements indicates a
phenomenon, which has not been investigated up to now. Such a research work has
been done for the first time through close cooperation of subprojects A and B3
of SFB (Sonder-ForschungsBereich: A special fire research activity for structural
elements in Braunschweig Technical University, 1971-1986). The results of the
rheological investigations presented in this paper can lead to a new research
conception about the determination of realistic fire behavior of concrete
structures. By means of further purposive research work, it will be possible to
reproduce the structural behavior in case of fire with simple but realistic mathematic-rheological
relationships.

Anahtar Kelimeler

Fire case, reinforced concrete, macro specimens, fire resistance, relaxation, material behavior

Kaynakça

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