When understanding the effect of the morphology of coarse aggregate on the properties of a fresh concrete mixture, the strength and deformability of self-compacting high-performance fibre-reinforced concrete (SCHPFRC) can be seen to be critical for its performance. In this research, regular and irregular grains were separated from granite coarse aggregate. The morphology of these grains was described while using digital image analysis. As a result, the aspect ratio, roundness and area ratio were determined in order to better understand this phenomenon. Then, the principal rheological, physical, and mechanical properties of SCHPFRC were determined. The obtained results indicated that the morphology of the grains of coarse aggregate has an impact on the strength and stiffness properties of SCHPFRC. Moreover, significant differences in the transverse strain of concretes were observed. The morphology of the coarse aggregate also has an impact on the rheological parameters of a fresh concrete mixture. To better understand this phenomenon, the hypothesized mechanism of the formation of SCHPFRC caused by different morphology of coarse aggregate was proposed at the end of the article.

Wp³yw rozdrabniania surowców skalnych w ró¿nych kruszarkach i stadiach kruszenia na jakooeae kruszyw mineralnych WprowadzenieUk³ady technologiczne przeróbki kruszyw mineralnych s¹ determinowane zró¿nico-wanymi formami wystêpowania surowców mineralnych w z³o¿ach. Równie¿ z³o¿onooeae i stopieñ skomplikowania technologii w danym uk³adzie instalacji uwzglêdnia rodzaj litologiczny surowca i jego w³aoeciwooeci fizykomechaniczne, które s¹ w szczególnooeci charakteryzowane wielkooeci¹ uziarnienia urobku (ziarno maksymalne lub oerednie, punkt piaskowy itp.), zwiêz³ooeci¹, urabialnooeci¹ i twardooeci¹, stopniem zanieczyszczenia surowca i rodzajem zanieczyszczeñ oraz przede wszystkim wymagan¹ jakooeci¹ koñcowych produktów pod wzglêdem wielkooeci granulometrycznej, kszta³tu ziaren i czystooeci gotowych kruszyw (zawartooeae py³ów i zanieczyszczeñ obcych) (Gawenda 2011a, b).Przy produkcji kruszyw ³amanych ze zwiêz³ych surowców skalnych oraz ¿wirowych w szerokim zakresie stosuje siê rozdrabnianie jako podstawow¹ operacjê technologiczn¹.Zale¿nie od wielkooeci bry³ surowca (nadawy), rozdrabnianie w przemyoele kruszyw przyjmuje formê kruszenia wstêpnego (grubego), oeredniego oraz drobnego poprzedzonego przesiewaniem, tworz¹c w ten sposób stadia rozdrabniania (Gawenda 2011a, 2010b; Saramak i in. 2010). Uk³ady wielostadialne s¹ budowane z ró¿nych maszyn rozdrabniaj¹cych, których dobór mo¿e mieae zarówno pozytywny jak i negatywny wp³yw na efekt koñcowy procesu produkcji kruszyw.

The article shows investigations on the behavior of preplaced aggregate concrete with regular and irregular coarse aggregates. The thermal properties, compressive strength, and internal structure were analyzed based on computed tomography images. The regular and irregular shapes of aggregates were obtained according to patented technology, which is possible to produce in both laboratory and industrial conditions. Based on the conducted calculations, heat storage capacity was assessed. The influence of grain shape on the material strength, porosity, and hydration gaps was determined. Debonded porosity, as a result of aggregate impurities, was shown using computer tomography analysis. It was shown that the arrangement and shape of the grains has a significant impact on the performance properties of hardened preplaced concrete.

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Clinoptilolite is a precious zeolite mineral that has the most comprehensive physicochemical properties among all the zeolite group minerals. Due to these unique properties, clinoptilolite has a wide range of applications in many different industries. In Poland, the clinoptilolite occurs only as an accompanying mineral in the sedimentary rocks nearby Rzeszów. In Europe, the abundant clinoptilolite-bearing deposits are located in Slovakia and Ukraine, where clinoptilolite mineralization occurs in the volcanic tuffs. Due to clinoptilolite’s rare performance, it is extremely crucial to manage its deposits in a complementary manner. In this paper, the mineralogical and structural characterization of the clinoptilolite powders obtained by mineral processing of the clinoptilolite-rich tuffs from Slovakia and Ukraine deposits were discussed. The scope of research covered determination of the mineral composition of the tuffs, structural analysis of the clinoptilolite crystals, as well as textural and physical properties of the powders obtained by mineral processing of the tuffs. In addition, this paper includes the comparative study of the most significant zeolite deposits in the world and investigated clinoptilolite-rich tuffs. A wide spectrum of methods was used: X-ray powder diffraction (XRD), thermal analysis (DSC, TG), X-ray fluorescence (XRF), optical microscopy, Scanning Electron Microscopy (SEM-EDS), the laser diffraction technique, and low-temperature nitrogen adsorption/desorption. The test results indicated that the major component of the tuffs is clinoptilolite, which crystallized in the form of very fine-crystalline thin plates. The clinoptilolite mineralization in the Ukrainian and Slovakian tuffs exhibited a strong resemblance to the clinoptilolite crystals in Yemeni and Turkish tuffs. With respect to the mineral composition, the investigated tuffs showed excellent conformity with the Miocene white tuffs from Romania. The Ukrainian and Slovakian tuffs do not reveal the presence of the clay minerals, which is quite common for naturally occurring zeolite-rich rocks in various deposits in the world. The textural features together with mineral composition of the investigated samples incline that they are potentially suitable raw materials for the sorbent of petroleum compounds. Moreover, the obtained results can be useful indicators with respect to the crushing and compaction susceptibility of the Ukrainian and Slovakian clinoptilolite-rich tuffs.