Patent ID: 8277705
Filing Date: 2012-10-02
Classification: E01B,Y10T

Abstract:
1. A method for restoring a damaged rail seat located on a concrete rail tie, which comprises providing said concrete rail tie, said damaged rail seat being located on the upper surface of said concrete rail tie; applying an uncured polymeric material comprising a substantially sag resistant poly (urethane-urea) material, having excellent pseudoplasticity, to the damaged rail seat located on the upper surface of said concrete rail tie, said uncured, sag resistant poly(urethane-urea) material being maintained in a fixed position on the damaged rail seat without substantial runoff therefrom during restoring of the damaged rail seat, said sag resistant uncured poly (urethane-urea) material comprising, without the addition of water to the uncured poly(urethane-urea) material, (a) at least one polyol compound, (b) at least one amine compound, (c) an isocyanate compound, and (d) a chain extender which reacts with said isocyanate compound to form said substantially sag resistant poly(urethane-urea) material, said chain extender comprising (i) at least one amine chain extender and/or (ii) at least one hydroxyl chain extender; prior to forming said restored cured rail seat, contouring the sag resistant uncured polymeric material applied to said damaged rail seat on the upper surface of the concrete rail tie in situ to form a sag resistant contoured damaged rail seat having substantially the original dimensions of an undamaged rail seat, the sag resistant contoured damaged rail seat being substantially contourable and maintaining its shape without substantial runoff from the concrete rail tie during said contouring of the uncured polymeric material; and curing the contoured damaged rail seat under ambient temperature and pressure conditions to form a restored cured rail seat, the uncured polymeric material of said sag resistant contoured damaged rail seat being substantially contourable and maintaining its shape without substantial runoff from the concrete rail tie during said restoration operation, wherein when the damaged rail seat located on the concrete rail ties is restored, the restored rail seat is properly bondable to an abrasion plate and maintains the gauge of a rail assembly under dynamic operating conditions.