| 主权项 |
1. An accelerated cure method for making a strong, high durometer, reduced brittleness hydrated sprinkler donut, wherein the accelerated cure method comprises:
a. mixing for 2 to 5 minutes 5 weight percent to 8 weight percent water with 92 weight percent to 95 weight percent of a dry mixture forming a first blend, wherein the dry mixture consists of:
(i) 30 weight percent to 53 weight percent sand;(ii) 20 weight percent to 40 weight percent Portland cement;(iii) 1 weight percent to 2 weight percent pigment; and(iv) 1 weight percent to 2 weight percent polypropylene homopolymer fibers cut into strands less than 0.5 of an inch in length; b. blending for 3 to 4 minutes the first blend with 0.5 weight percent to 1 weight percent of an accelerating admixture, forming a donut material, wherein the accelerating admixture consists of:
(i) 30 weight percent to 60 weight percent calcium chloride; and(ii) 40 weight percent to 60 weight percent water, wherein the weight percent of the water is based on the total weight percent of the first blend with the accelerating admixture; c. spraying at least one donut shaped mold with a urethane release agent in a thickness of at least 1 ml; d. placing the donut shaped molds in a controlled environment, wherein the controlled environment is at a temperature from 96 degrees Fahrenheit to 101 degrees Fahrenheit and at a humidity of at least 85 percent; e. depositing the donut material into the sprayed donut shaped mold in the controlled environment; f. spraying an evaporation retardant on the donut material prior to cure, within 8 minutes of placing the donut material in the sprayed donut shaped mold in the controlled environment, wherein the evaporation retardant prevents evaporation of water from the donut material; g. allowing the donut to remain in the mold 8 to 12 hours in the controlled environment; and h. removing the donut from the mold for use around sprinkler heads of irrigation systems. |
