Strength characteristics of fiber-reinforced light shotcrete

Konstantin Alekseev,Alexsandr Kurilko,I Rasskazov,S Tkach

doi:10.1051/e3sconf/202019201020

Abstract

The article presents the regularities of the flexural and compressive strength variation, as well as the energy intensity of destruction of light heat-shielding vermiculite concrete, depending on the content of polypropylene or basalt fiber. The paper stresses that the greatest increase in flexural strength of 40% is observed at the polypropylene or basalt fiber that the greatest increase in flexural strength of 40% is observed at the polypropylene or basalt fiber of 2 and 2-4% respectively. As the basalt fiber content increases from 1 to 4%, the compressive strength increases from 42 to 83%. The resistance of vermiculite concrete to dynamic bending loads when the polypropylene fiber ranges from 0.5 to 2% by a factor of 2.5 4.2. With basalt fiber content of 1 to 4% the energy intensity of destruction increases 1.5 2.5 times.Specific energy intensity of destruction of samples reinforced with basalt fiber increases by 2.3 ÷ 2.7 times during volumetric destruction of the specimens under study on a vertical pile driver. The regularities obtained in the course of the studies indicate that fiber reinforcement of light heat-shielding vermiculite concrete increase its strength characteristics and thereby expand the scope of its application.

Highlights

Underground method of mining becomes more and more widespread in accordance with development of diamond, gold, coal and industries of Republic Sakha (Yakutia)
The flexural strength determines on samples measuring 40x40x160mm and the compression onesis on the half beams
The passport characteristics of concrete are flexural and compressive strength- under static loads, but the torque-concrete fastenings and coatings erected in mines and mines are subject to more dynamic effects energy rate

Summary

Introduction

Underground method of mining becomes more and more widespread in accordance with development of diamond, gold, coal and industries of Republic Sakha (Yakutia). Formulations of thermal shotcretewith the use of fillers of local production, vermiculite, ceramic, azerite, are developed They have been found to protect the permafrost rocks from the impact of the aggressive mining atmosphere, and to reduce several times the number of freezing-thawing cycles of the test sediments during the year and reduce the size of the halos of thawing around the opening mineworkings in summer [5]. The range of fibers used is very extensive: from extremely scarce, for example, carbon, boron, tungsten, to those comparatively available for use in mass construction - steel, basalt, polypropylene, etc.The fiber to be used must meet a number of requirements: high strength, chemical resistance, evenly distributed in the volume of the cement test or concrete without the formation of heterogeneous bundles adversely affecting the final strength of the product. The fiber content of the mixture varies from 0.5 to 4% of the total mass of the components of the mixture (table 1)

Type of fiber

Vertical pile driver

Findings

Conclusion