MİKRODALGA ÖN İŞLEMİNİN TRAVERTEN VE MERMERİN KIRILMA HIZINA VE ULTRASONİK ÖZELLİKLERİNE ETKİSİ

In this study, the effect of microwave treatment on breakage rate and ultrasonic velocity of travertine and marble has been investigated. The specific rates of breakage (Si) of -850+600 µm particle size fractions of travertine and marble have been determined using a laboratory scale ceramic ball mill. The dry grinding of the samples treated and untreated with microwave followed the first-order breakage law, and the found Si values increased with parallel to increasing of microwave power. However, a significant increase in the Si values was not obtained at microwave power values higher than 600 W. On the other hand, the Si values obtained for marble increased significantly as the microwave treatment times became longer. But, the breakage rate of travertine was not improved with increasing treatment time after reaching a particular value. In addition, the values of ultrasonic velocity of these materials showed a decreasing trend with increasing microwave power and treatment time. Consequently, a partial relationship was found between the ultrasonic velocity value and breakage rate, which indicates that the ultrasonic velocity decreases, as the Si values increases.Bu çalışmada, traverten ve mermerin kırılma hızı ile ultrasonik özelliklerine, mikrodalga muamelesinin etkisi araştırılmıştır. Traverten ve mermerin -850+600 µm tane boyut sınıfının özgül kırılma hızları, laboratuar ölçekli seramik bir bilyalı değirmen kullanılarak tespit edilmiştir. Mikrodalga ile muamele edilen ve edilmeyen örneklerin kuru öğütülmesi, birinci dereceden kırılma kanununu izlemiş ve bulunan Si değerleri mikrodalga gücünün artışına paralel olarak artmıştır. Bununla birlikte, 600 W’tan daha yüksek mikrodalga güçlerinde Si değerlerinde önemli bir artış elde edilememiştir. Diğer taraftan; mermer için elde edilen Si değerleri, mikrodalga muamele süresi uzarken önemli ölçüde artmıştır. Ancak, travertenin kırılma hızı belirli bir değere ulaşıldıktan sonra artan muamele süresi ile iyileştirilememiştir. Ayrıca, bu malzemelerden geçen ultrasonik hız değerleri artan mikrodalga gücü ve muamele süresi ile azalan bir eğilim göstermiştir. Dolayısıyla, ultrasonik hız değeri ve kırılma hızı arasında, ultrasonik hız azalırken Si değerlerinin artışını işaret eden kısmi bir ilişki bulunmuştur

GEOLOGICAL AND GEOMECHANICAL PROPERTIES OF SOME CARBONATE MARBLES AND BASALT STONE FROM MOROCCO

The natural rocks used today as well as in the history for a variety of purposes were a subject of different alteration, weathering and deterioration conditions. These conditions are strictly controlled by environment and nature of rock varieties (marble and stone). This study is a first approach to understand the relation between some geological features and behavior against salt (Na 2SO4) decay of Moroccan marbles and stones. For this purpose, widely used four dolomitic limestones, two crystalline limestones, one limestone and one basalt sample (total 8) were chosen from Morocco. Extra attention paid to choose locations being a representative of all Moroccan country. The carbonate samples (limestone and dolomite) consist of mainly dolomite and calcite with micritic and sparitic cement. The sole, non-carbonaceous sample is basalt of Khenifra containing mainly plagioclase and pyroxene. In general, both bulk-dry and powder density values of the studied rock samples are homogeneous. The limestone of Bir Jdid has the highest (10.81 %) effective porosity and dry weight loss value (4.61 %). The loss on ignition value of the Khenifra basalt has the lowest value with 1.26 %. The loss on ignition values are also relatively uniform. The obtained data indicate that outdoor uses (especially in coastal areas) of limestones of Bir Jdid and dolomitic limestones of Taza are more risky than the others