Durable railway tie

Patent metadata

Field	Value
Publication number	US-10781557-B2
Application number	US-201615550304-A
Country	US
Kind code	B2
Filing date	Feb 10, 2016
Priority date	Feb 11, 2015
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

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).

First claim

What is claimed is:

1. 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/m 3 ,
fly ash in the range of 600-800 kg/m 3 ;
silica fume in the range of greater than 0 to 100 kg/m 3 ;
sand in the range of 350-550 kg/m 3 ;
water in the range of 300-400 kg/m 3 ;
polymer fiber in the range of 1-3% by volume;
superplasticizer in the range of 5-30 kg/m 3 ; and
viscosity modifying admixture in the range of greater than 0 to 30 kg/m 3 , 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.

2. The railway tie according to claim 1 , further comprising: fly ash cenospheres in the range of 0-300 kg/m 3 .

3. The railway tie according to claim 1 , further comprising: tire rubber in the range of 0-200 kg/m 3 .

4. The railway tie according to claim 1 wherein the cement is a Type I or Type III.

5. The railway tie according to claim 1 wherein the fly ash is a Class F or Class C.

6. The railway tie according to claim 1 , further comprising fly ash cenospheres that reduce the density of the railway tie.

7. The railway tie according to claim 1 wherein the elongated body is absent of internal reinforcement members.

8. The railway tie according to claim 1 having a life span of at least 100 years.

9. 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/m 3 ,
fly ash in the range of 600-800 kg/m 3 ;
silica fume in the range of greater than 0 to 100 kg/m 3 ;
sand in the range of 350-550 kg/m 3 ;
water in the range of 300-400 kg/m 3 ;
polymer fiber in the range of 1-3% by volume;
superplasticizer in the range of 5-30 kg/m 3 ; and
viscosity modifying admixture in the range of greater than 0 to 30 kg/m 3 , 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.

Assignees

• Univ Michigan Regents

Inventors

• Li Victor C
• Herbert Emily

Classifications

• E01B3/28 Primary

  made from concrete or from natural or artificial stone (manufacture B28) · CPC title

• C04B2201/52

  High compression strength concretes, i.e. with a compression strength higher than about 55 N/mm2, e.g. reactive powder concrete [RPC] · CPC title

• C04B2103/32

  Superplasticisers · CPC title

• C04B16/06

  fibrous · CPC title

• Y02A30/30

  in transportation, e.g. on roads, waterways or railways · CPC title