Comparative Study of Physicomechanical Properties of Ultrabasic Rocks and Andesites From Central Macedonia (Greece)

Abstract

Petrographic, geochemical and physicomechanical features were determined and inter-correlated in two representative ultrabasic samples from the Veria-Naousa ophiolite and two Pliocenic andesite samples, occurring at the east of the above complex. Results show that mineralogical and textural features are major factors affecting the physicomechanical properties in both lithotypes. The ultrabasic rocks display higher resistance to attrition and abrasion and lower water absorption values relative to the intermediate volcanic rocks, hence the first are predicted to show better in-service engineering performance. However, the degree of serpentinisation is detrimental, as a highly serpentinised ultrabasic sample yielded poor results, analogous to the andesites, in certain laboratory tests. Ophiolite complexes in Greece are abundant and they are distributed along several mainland areas. Hence setting evaluation criteria for their quality is important as they can potentially replace limestones, which are less resistant and durable, in several environmental and industrial applications

The Impact of Secondary Phyllosilicate Minerals on the Engineering Properties of Various Igneous Aggregates from Greece

“…The physicomechanical properties of the aggregates depend on the mineralogical composition, textures (size, shape, and arrangement of mineral grains, nature of the grains contact, and degree of grain interlocking), degree of alteration, and deformation degree of the source rocks [2][3][4][5][6][7] in their classification for engineering purposes. Many researchers have studied the relationships between physical and mechanical tests in order to investigate the impact of the alteration degree of various rock samples or other petrographic characteristics (i.e., the structural complexity of serpentine) and how they affect the engineering properties of rocks [8][9][10][11][12]. Moreover, changes in textural characteristics affect their physicomechanical properties, which vary from excellent to fair, becoming poor to very poor when extensive alteration and intense deformation is present [13].…”

The Impact of Secondary Phyllosilicate Minerals on the Engineering Properties of Various Igneous Aggregates from Greece

“…the structural complexity of serpentine) and how they affect the engineering properties of rocks [9,10,12,22]. Regression analysis is the commonest statistical method for the investigation the interdependence of the physical and mechanical parameters.…”

“…Physicomechanical properties depend on the mineralogy, texture (size, shape and arrangement of mineral grains, nature of grains contact, and degree of grain interlocking), alteration and deformation degree of the source rock [1][2][3][4][5][6]. The mineralogical composition of the aggregates and more specifically their alteration degree strongly influences their mechanical behaviour and in-service performance [7][8][9][10]. Increased percentages of certain secondary minerals, such as serpentine, chlorite, talc and smectite affect negatively the physical as well as the mechanical X-ray Diffraction (XRD) is considered the best technique to identify and quantify all minerals present in the studied rock samples.…”

The Effect of Petrographic Characteristics and Physico-Mechanical Properties of Aggregates on the Quality of Concrete

“…Therefore, mineralogy and microstructure of the coarse aggregates affected the final strength of the concrete specimens.factor for the quality of concrete. For the same quality cement, different lithotypes of coarse aggregates characterized by different micro-roughness, mineralogical composition, structure and compressive strength may result in different concrete compressive strength [10,11].Mineralogical composition of the aggregates, and more specifically their alteration degree, strongly influence their mechanical behavior and their in-service performance [10,[12][13][14][15][16][17]. Increased percentages of certain secondary minerals negatively affect the physical, as well as the mechanical properties of aggregates due to their smooth layers, cleavage and platy or fibrous crystal habit [10,17], which have an adverse effect on their performance as concrete aggregates [10].…”

“…Mineralogical composition of the aggregates, and more specifically their alteration degree, strongly influence their mechanical behavior and their in-service performance [10,[12][13][14][15][16][17]. Increased percentages of certain secondary minerals negatively affect the physical, as well as the mechanical properties of aggregates due to their smooth layers, cleavage and platy or fibrous crystal habit [10,17], which have an adverse effect on their performance as concrete aggregates [10].…”