İsmail HOCAOĞLU, Tayfun UYGUNOĞLU

Alternatif Gerilim Uygulanan Betonlarda S/Ç Oranının ve Hiperakışkanlaştırıcı Oranının Priz Bitiş Süresi ve Basınç Dayanımına Etkilerinin Araştırılması

Bu çalışmada su/çimento oranları 0.45, 0.55, 0.65 ve 0.70 olan 300 dozajlı betonlara 80 V AC gerilim uygulanmıştır. S/ç oranları 0.55 olan % 0.5, % 1 ve % 1.5 oranlarında hiperakışkanlaştırıcı konulan betonlar üretilmiştir. Taze haldeki betonlar elektriksel yalıtımlı 10cm x 10cm x 35cm boyutlarındaki kalıplar içerisinde elektrik akımı uygulanmış, ölçümler oda sıcaklığında yapılmıştır. Elektrik akımı uygulanmış ve elektrik akımı uygulanmamış numunelerde iç sıcaklık ölçümü ile priz bitiş süresi belirlenmiştir. Alternatif gerilimin, s/ç oranının ve hiperakışkanlaştırıcı oranının priz sona erme süresi, 1 günlük basınç dayanımı ve 28 günlük basınç dayanımına etkileri araştırılmıştır. Bu araştırmada betona belirli oranda hiperakışkanlaştırıcı konulması ve alternatif gerilim uygulaması sonucu priz bitiş süresinin kısaltılması amaçlanmıştır. Betonlara az miktarda (% 0.5) hiperakışkanlaştırıcı konulması ve 80 V AC gerilim uygulaması ile ciddi basınç dayanım kaybı yaşanmadan priz süresinin kısaltılabileceği belirlenmiştir.

Anahtar Kelimeler:

Alternatif gerilim, beton, priz bitiş süresi

Investigation of the Impacts of W/C Ratio and Hyper Plasticizer Ratio on Final Setting Time and Compressive Strength for the Concretes to which Alternating Current Applied

In this study, 80 V AC current is applied to 300 dosaged concretes whose water/cement ratios are 0.45, 0.55, 0.65 and 0.70. Admixtures having different hyper plasticizer ratios (0.5 %, 1 % and 1.5 %) and admixtures having constant water/cement ratio (0.55) at 300 dosaged levels were prepared. Electrical current was applied to the fresh concretes in the electrically isolated molds whose sizes are 10cm x 10cm x 35cm. The measurements were done at room temperature. As a result of measuring internal temperatures of concretes, the differences between final setting time with and without electric current application on the specimens were investigated. The effects of Alternating Current (AC), water/cement ratio, hyper plasticizer ratio on final setting time, 1 day compressive strength and 28 day compressive strength are investigated. It is aimed to shorten the duration of final setting time through adding hyper plasticizer in a certain rate to the concrete and application of AC current. As a result, adding little hyper plasticizer (0.5 %) and application of 80 V AC electrical current to the concretes shorten the setting time without critical compressive strength loss.

Keywords:

Alternating voltage, concrete, final setting time,

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