The effects of using of sinter magnesite on cement mortarproperties

In this study, it is aimed to examine the effects of using sinter magnesite in different grain sizes on cement mortar properties. For this purpose, two different grain size(dmax 2mm and dmax 1mm) of sinter magnesit(MgO) was used in different proportions instead of standard sand in standard cement mortar. In order to prevent cracks that may occur in the samples, basalt fiber was added to some samples at a rate of %0.2 by volume. Experimental methods such as ultrasound transmission speed, high temperature application, compressive strength and microstructure examination were applied on the samples produced with %0(reference), %25, %50, %75 and %100 sinter magnesite. The 'sintered magnesite' chosen for the study is the raw material of the alkaline refractory industry. Therefore, it is thought that its use in cement mortar will increase its resistance against high temperatures. The cube samples of 50x50x50 mm prepared for the study were exposed to high temperatures at three different temperature levels. Mortar samples, which were water cured for 28 days, were heated to three different temperatures of 600, 700 and 800 ºC at 6 ºC/min and kept at these temperatures for 1 hour. Then, ultrasound transmission speed, compressive strength and microstructural examination tests were performed on the samples, which were cooled to room temperature with slow cooling. According to the test results; the highest compressive strengths of 28 days in the sample groups that were not subjected to high temperature were measured in the samples prepared by using sinter magnesite. At the highest temperature level of 800 ºC applied in the study; in the samples using %25 sinter magnesite, higher strengths were obtained than the reference samples.