Investigatigation of the effect of boiling tests on the engineering properties of sonnenbrand basalts

In this study, the effects of boiling tests on the engineering properties (i.e. fragmentation, mass-, abrasion-, compressive strength loss, decrease in ultrasonic P-wave velocity and microstructural properties etc.) of sonnenbrand basalts are investigated for the first time within the scope of this thesis study. Boiling tests did not cause neither splitting nor disintegration in any of the sonnenbrand basalts. However, all rocks exposed to boiling were observed to turn one tone lighter color than those of control samples when they were completely dried. Boiling tests for sonnenbrand basalts were seen to cause a high weight loss (~10%) in basalts with weak texture. Additionally, weak texture and high porosity led to relatively higher Los Angeles abrasion loss (%) in rocks. Loss of compressive strength and decrease in ultrasonic P-wave velocity values were observed in all basalt rocks subjected to the boiling tests. Thin section examinations supported above findings where Artvin basalts showed very intense alterations which are highest in Artvin (B). The reasons underneath the mass and abrasion losses and the decrease in uniaxial compressive strength and ultrasonic P-wave velocity values were investigated under scanning electron microscope (SEM) weather these results stem from the microstructure of the rocks when subjected to boiling tests besides weathering. SEM examinations suggested that the boiling tests caused weakening in the texture of the rocks.