Strength, Frost Resistance, and Resistance to Acid Attacks on Fiber-Reinforced Concrete for Industrial Floors and Road Pavements with Steel and Polypropylene Fibers

Abstract

A comparison of the effect of steel and polypropylene fibers on the strength, frost resistance, abrasion, and corrosion resistance in an acidic environment of fiber-reinforced concrete for industrial floors and road pavements was carried out. Steel fibers with a length of 50 mm and a diameter of 1 mm and polypropylene fibers with a length of 36 mm and a diameter of 0.68 mm were used. The amount of steel fiber varied from 15 to 25 kg/m3, and the amount of polypropylene fiber varied from 2 to 3 kg/m3. It has been established that steel fiber more significantly increases the concrete compressive strength, and both types of dispersed reinforcement increase the flexural strength equally by 27–34%. Also, dispersed reinforcement reduces the concrete abrasion resistance by 15–35% and increases its frost resistance by 50 cycles, which helps to improve the durability of industrial floors and road pavements. The use of steel fiber in an amount of 20 kg/m3 and polypropylene fiber in an amount of 2.5 kg/m3 also increases the concrete corrosion resistance in an acidic environment. In general, dispersed reinforcement with both fiber types has approximately the same technological effect concerning the mentioned applications. However, the use of polypropylene fibers is economically more profitable since an increase in the cost of 1 m3 of concrete with steel fiber reinforcement is from $22.5 to $37.5, and an increase in cost with polypropylene fiber is from $10 to $15.

Influence of Polymer Fibers on the Structure and Properties of Modified Variatropic Vibrocentrifuged Concrete

“…As for individual factors, as mentioned earlier, the VCC modified with polypropylene fiber showed the least improvement in performance. And first of all, this is due to the fact that polypropylene fiber itself has lower strength and deformation characteristics than concrete itself, and cannot properly perceive the stresses arising in concrete and redistribute them [ 8 , 31 , 32 ]. Modification of VCC with basalt fiber is more effective, since basalt fiber has a higher elastic modulus, tensile strength, and when stresses occur in the composite structure, it prevents microcrack formation [ 11 , 12 , 13 , 14 , 69 ].…”

“…Such scientific deficiencies are especially pronounced in non-traditional types of fibers for normal-density concrete and, first of all, for variatropic concrete [ 7 ]. Note that in the technology of normal-density concrete, durable types of fibers, such as steel and basalt, are often used, and polypropylene polymer fibers are used much less frequently [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. However, in our opinion, an interesting direction that can lead to a number of new results is dispersed reinforcement of variatropic concrete with polymer fibers, namely polypropylene fiber.…”

“…Polypropylene and basalt fibers are the most popular and most often used in the technology of normal-density concrete, and the effectiveness of their use has been confirmed by many scientific studies [ 8 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. Basalt fiber is of inorganic origin, obtained by melting basalt rock in smelting furnaces and drawing continuous threads from this melt through special dies, which are subsequently dried and chopped into fibers.…”

“…Polypropylene fiber is produced by extrusion. Special raw materials are brought to high temperatures and passed through holes with an individual profile and cross-section, and then the resulting fibers are cut to the required length [ 8 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ].…”

“…The introduction of polypropylene fibers into the composition of normal-density concrete also helps to improve its characteristics. For example, in works [ 8 , 31 ], concrete containing polypropylene fiber showed better frost resistance. During multiple freeze–thaw cycles in an aggressive environment, polypropylene fibers effectively suppress the propagation of microcracks and prevent concrete destruction.…”