Durability of Modified Fiber Concrete for Rigid Pavements

Abstract

Abstract Modified concretes and fiber concretes for rigid pavements have been investigated. Four-factor experiment was conducted. The amount of Portland cement, polypropylene fiber, metakaolin and polycarboxylate superplasticizer varied in the experiment. All mixtures had the same mobility S2. The active mineral additive metakaolin increases the compressive strength of concrete and its tensile strength in bending. The amount of metakaolin at the level of 15.20 kg/m3 is rational. Due to a decrease in W/C with an increase in the amount of superplasticizer Coral ExpertSuid-5 to 0.9.1%, the compressive strength of concrete increases by 5.7 MPa, the tensile strength in bending increases by 0.5.0.6 MPa. Due to the introduction of polypropylene fiber, the tensile strength of concrete in bending increases by 0.6.0.9 MPa, the frost resistance of concrete increases by 50 cycles. Due to the use of a rational amount of superplasticizer and metakaolin, the frost resistance of concretes and fiber concretes concrete increases by 50-100 cycles. The use of a rational amount of modifiers and fiber reduces the abrasion of concretes by 40.45%. The developed modified fiber concretes of rigid pavements, depending on the amount of Portland cement, have compressive strength from 55 MPa to 70 MPa, tensile strength in bending from 8 MPa to 9.5 MPa, frost resistance from F350 to F450, abrasion from 0.30 to 0.40 g/cm2. Such strength, frost resistance and abrasion resistance allow the use of fiber concretes in pavements with the greatest load and ensures high durability of the material and corresponds to the directions and tasks of the state scientific and technical program “National Transport Strategy of Ukraine for the period up to 2030”