Pavement overlay material and method
View Patent ↗A mix design for a polymer modified cement pavement overlay is disclosed along with a method of making and using the mix on a variety of pavement substrates. The mix includes a specific dry combination of: finely divided Elotex 2311 and 2322 or 2320 polymers; Type 2 or C144 aggregate or equivalent; Type I/II cement; Type F or Type C fly ash; intermediate length polymer microfibers; plasticizer; (optionally) calcium chloride or equivalent; (optionally) quikrete retarder or equivalent; and water. The mixture is combined and applied to the substrate in depths of about ⅛ to about 1 inch in lifts. The mixture is allowed to cure for 3-4 hours before being returned to traffic. The placed mixture exhibits preferred qualities of substrate adhesion, flexibility, tire friction, and wearability.
1. A polymer modified cement pavement overlay mixture, comprising by weight:
a redispersible binder based on a copolymer of vinyl acetate and ethylene formulated to improve workability and void distribution, about 0.5 wt % to about 1.0 wt %;
a redispersible binder based on a copolymer of vinyl acetate and ethylene formulated to improve cured state flexibility and adhesion with a substrate, about 3.0 wt % to about 3.5 wt %;
masonry mortar aggregate (ASTM C144) about 49 wt % to about 59 wt %;
type II hydraulic Portland cement about 15 wt % to about 25 wt %;
class C or class F fly ash about 1 wt % to about 20 wt %;
polycarbonate superplasticizer about 0 wt % to 2 wt %;
polypropylene microfibers, about 0.25 to about 1.5 inches long, about 0.8 wt % to about 1.16 wt %; and
water about 11 wt % to about 21 wt %.
2. A mixture as in claim 1 , further comprising:
calcium chloride about 0.01 wt % to about 10 wt % blended with a retarding admixture (ASTM C494 Type B) about 0 wt % to about 5 wt %.
3. A method of making a pavement overlay mixture, comprising the steps of:
combining
a redispersible binder based on a copolymer of vinyl acetate and ethylene formulated to improve workability and void distribution, about 0.5 wt % to about 1.0 wt %;
a redispersible binder based on a copolymer of vinyl acetate and ethylene formulated to improve cured state flexibility and adhesion with a substrate, about 3.0 wt % to about 3.5 wt %;
masonry mortar aggregate (ASTM C144) about 49 wt % to about 59 wt %;
type II hydraulic Portland cement about 15 wt % to about 25 wt %;
class C or class F fly ash about 1 wt % to about 20 wt %;
polycarbonate superplasticizer about 0 wt % to 2 wt %; and
polypropylene microfibers, about 0.25 to about 1.5 inches long, about 0.8 wt % to about 1.16 wt % in a dry form blend;
adding said dry blend to a mixing machine containing water apportioned as about 11 wt % to about 21 wt %, all said percentages being by weight of said overlay mixture; and
mixing for more than 5 minutes.
4. A method as in claim 3 , further comprising the step of:
testing said mixture following mixing for flowability in a standard ASTM flow meter cone test such that time required for passthrough is consistently between 5 and 60 seconds.
5. A hardened pavement overlay, comprising:
a ⅛ to 1 inch thick, screed placed, and 4 hour cured mixture, including by weight prior to placement:
a redispersible binder based on a copolymer of vinyl acetate and ethylene formulated to improve workability and void distribution, about 0.5 wt % to about 1.0 wt %;
a redispersible binder based on a copolymer of vinyl acetate and ethylene formulated to improve cured state flexibility and adhesion with a substrate, about 3.0 wt % to about 3.5 wt %;
masonry mortar aggregate (ASTM C144) about 49 wt % to about 59 wt %;
type II hydraulic Portland cement about 15 wt % to about 25 wt %;
class C or class F fly ash about 1 wt % to about 20 wt %;
polycarbonate superplasticizer about 0 wt % to 2 wt %;
polypropylene microfibers, about 0.25 to about 1.5 inches long, about 0.8 wt % to about 1.16 wt %; and
water about 11 wt % to about 21 wt %.
6. A hardened pavement overlay as in claim 5 , further comprising by weight prior to placement:
calcium chloride about 0.01 wt % to about 10 wt % blended with a retarding admixture (ASTM C494 Type B) about 0 wt % to about 5 wt %.