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US 10,781,557 B2Granted
Durable railway tie
AssigneeThe Regents of the University of Michigan
InventorsVictor C. Li, Emily Herbert
Life of this patent
Estimating the term…
Abstract
A railway tie being constructed of an engineered cementitious composite (ECC) material having: (1) a minimum of 2% tensile ductility of ECC, (2) complete absence of alkali-silica reaction (ASR), (3) high fatigue resistance of ECC at least five times that of normal concrete, (4) self-healing ability of ECC requiring only water and air, and (5) customization of ECC for lower stiffness in the tie (60% that of normal concrete) and higher abrasion resistance in the seat (three times that of normal concrete).
Claims9
A railway tie comprising:
- an elongated member comprising an elongated body and at least one rail seat portion that supports and contacts a railway rail, wherein the at least one rail seat portion is abrasion resistant and is made of a non-prestressed, self-healing engineered cementitious composite material, said material having a mixture of:
- cement in the range of 500-700 kg/m3,
- fly ash in the range of 600-800 kg/m3;
- silica fume in the range of greater than 0 to 100 kg/m3;
- sand in the range of 350-550 kg/m3;
- water in the range of 300-400 kg/m3;
- polymer fiber in the range of 1-3% by volume;
- superplasticizer in the range of 5-30 kg/m3;
- and
- viscosity modifying admixture in the range of greater than 0 to 30 kg/m3, resulting in performance characteristics of at least:
- compressive strength greater than 150 MPa;
- first cracking tensile strength greater than 3 MPa;
- ultimate tensile strength greater than 5 MPa;
- tensile strain capacity greater than 2%;
- flexural strength greater than 15 MPa;
- and
- crack widths less than 100 μm.
14 more elements
A railway tie comprising:
- an elongated member comprising an elongated body and at least one rail seat portion that supports and contacts a railway rail, wherein the elongated member is made of a non-prestressed, self-healing engineered cementitious composite material, said material having a mixture of:
- cement in the range of 500-700 kg/m3,
- fly ash in the range of 600-800 kg/m3;
- silica fume in the range of greater than 0 to 100 kg/m3;
- sand in the range of 350-550 kg/m3;
- water in the range of 300-400 kg/m3;
- polymer fiber in the range of 1-3% by volume;
- superplasticizer in the range of 5-30 kg/m3;
- and
- viscosity modifying admixture in the range of greater than 0 to 30 kg/m3, wherein the at least one rail seat portion is abrasion resistant and has performance characteristics of:
- compressive strength greater than 200 MPa;
- first cracking tensile strength greater than 3 MPa;
- ultimate tensile strength greater than 5 MPa;
- tensile strain capacity greater than 2%;
- flexural strength greater than 15 MPa;
- and
- crack widths less than 100 μm,
- wherein the elongated member is free of any internal reinforcement members.
15 more elements
Dependencies are inferred from the claim text.