Investigation of Compressive Strength and Modulus of Elasticity of Calcium Aluminate Cement Concretes with Different Water/Cement Ratios at High Temperature

Abstract

In recent years, calcium aluminate cement can be used as a binder in high performance concrete design. Calcium aluminate cement is a cement type with superior performance against high temperatures and acidic environments. It can also be used as a repair mortar due to its fast hardening ability. However, unlike Portland cement, the hydration mechanism is greatly affected by temperature and humidity. Hydration products tend to become stable by undergoing some transformations. These transformations negatively affect the mechanical properties of calcium aluminate cement concrete. Therefore, the factors affecting the hydration mechanism of calcium aluminate cement should be investigated. In this respect, it is very important to determine the optimum water/cement ratio in concrete with calcium aluminate cement. In the present study, compressive strength and modulus of elasticity of calcium aluminate cement concretes with different water/cement ratios (0,35, 0,40, 0,45) at normal and high temperatures (600 ºC) were investigated. As a result of the study, it was determined that the loss of compressive strength and modulus of elasticity under high temperature increased as the water/cement ratio increased in the calcium aluminate cemented concrete. In terms of workability and strength parameters, the water/cement ratio in the range of 0,35-0,40 is a reasonable value in the design of calcium aluminate cement concrete.

Keywords

• Calcium aluminate cement concrete
• High Temperature
• Water/cement ratio

Farklı Su/Çimento Oranlarına Sahip Kalsiyum Alüminat Çimentolu Betonların Yüksek Sıcaklıkta Basınç Dayanımlarının ve Elastisite Modüllerinin İncelenmesi

Abstract

Son yıllarda yüksek performanslı beton tasarımında bağlayıcı olarak kalsiyum alüminat çimentosu kullanılabilmektedir. Kalsiyum alüminat çimentosu yüksek sıcaklıklara ve asidik ortamlara karşı üstün performans gösteren bir çimento türüdür. Aynı zamanda çok hızlı sertleşme kabiliyeti sayesinde tamir harcı olarak da kullanılabilmektedir. Ancak Portland çimentosunun aksine hidratasyon mekanizması sıcaklık ve nemden büyük ölçüde etkilenir. Hidratasyon ürünleri belli dönüşümlere uğramak suretiyle kararlı hale geçme eğilimindedirler. Bu dönüşümler kalsiyum alüminat çimentolu betonun mekanik özelliklerini negatif anlamda etkiler. Bu nedenle kalsiyum alüminat çimentosunun hidratasyon mekanizmasına etki eden faktörlerin araştırılması gerekir. Özellikle kalsiyum alüminat çimentolu betonda optimum su/çimento oranın tespiti bu açıdan oldukça önemlidir. Bu çalışmada farklı su/çimento oranlarına sahip (0.35, 0.40, 0.45) kalsiyum alüminat çimentolu betonların normal sıcaklıkta ve yüksek sıcaklıkta (600 ºC) basınç dayanımları ve elastisite modülleri araştırılmıştır. Çalışma sonucunda yüksek sıcaklık altında kalsiyum alüminat çimentolu betonda su/çimento oranı arttıkça basınç dayanımı ve elastisite modülü değerlerindeki azalma oranının arttığı tespit edilmiştir. İşlenebilirlik ve dayanım parametreleri birlikte değerlendirildiğinde kalsiyum alüminat çimentolu betonun tasarımında 0,35-0,40 aralığındaki su/çimento oranının makul bir değer olabileceği değerlendirilmiştir.

Keywords

• Kalsiyum alüminat çimentolu beton
• Yüksek sıcaklık
• Su/çimento oranı

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