Innovative Developments for Improving the Accuracy of Assessment of Physical-Mechanical Properties of Construction Rocks at Geological Exploration

For determining the principal possibility to use rocks for production of crushed stone, some their parameters are studied under the laboratory conditions according to normatives. The data obtained are the basis for designing the processing technology and preliminary assessment of possible ways for using final marketable products in a particular type of construction. It is known that the content of grains of plate and needle-shaped forms is a factor which significantly reducing their physical-mechanical characteristics. Crushed stone for testштп is produced from an initial core or massive geological sample by means of one-stage crushing in the laboratory screw crushers, a feature of which is a high content of plate and needle-shaped grains in the product of crushing. On the example of tests of granite crushed stone from one of the Karelian deposits, it is shown that this leads to conservative values of main strength characteristics (durability, abradability and frost resistance) and significantly reduces the accuracy of predictive assessment of the crushed rock quality. “Mekhanobr-Tekhnika” Research and Engineering Corporation proposes a new design of the laboratory screw crusher 2SHCHDS 100х200 which provides the receiving of initial feeding of up to 100 mm fineness and obtaining of the crushed product of 0–40 mm fineness. Complex reciprocating and elliptical motions of a crushing jaw provides the application of shear and compression forc- es to the material being crushed and makes it possible to obtain the crushed stone with a low share of plate and needle-shaped grains that corresponds to the content of such grains in the crushed stone produced in the production conditions. This makes it possible to compare correctly physical properties of industrial crushed stone and crushed stone produced under the laboratory conditions.

V.N. AMINOV¹, Doctor of Sciences (Engineering),
E.E. KAMENEVA¹, Candidate of Sciences (Engineering);
I.D. USTINOV², Doctor of Sciences (Chemistry) 

¹ Petrozavodsk State University, (33, Lenin Street, Petrozavodsk, 185910, Russian Federation) 
² Research and Engineering Corporation «Mekhanobr-Tekhnika» (22, Line 3, Vasilevsky Ostrov, 199106, Saint Petersburg, Russian Federation)

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