| 摘要 |
High SRI cementitious systems comprising integral concrete coloring admixtures, toppings, dry-shake hardeners, and other cementitious systems are provided. The high-SRI cementitious systems comprise one or more IR reflective pigments and other components to make-up the cementitious system, depending on the application. The high-SRI cementitious systems of the invention may be in the form of mixtures which increase the total solar reflectivity (TSR or albedo) and the Solar Reflectance Index (SRI) of concrete. The high-SRI cementitious systems may be toppings mixed with water for application to existing concrete surfaces, dry-shake hardeners for application to freshly-placed plastic concrete, or the IR reflective pigments may be mixed into integrally colored concrete in various forms, such as conventional cast-in-place concrete, lightweight concrete, pervious concrete and concrete building panels, pavers or masonry units. |
| 主权项 |
1. A method of preparing colored concrete, the method comprising the step of combining:
(i) components of a cementitious composition, the composition selected from the group consisting of a topping, a dry-shake color hardener, and an integral concrete coloring admixture; and (ii) an infrared reflective pigment composition, thereby forming a high-solar reflectance index (SRI) cementitious system, wherein the infrared reflective pigment composition comprises one or more infrared reflective pigments compliant with ASTM C979 and selected from the group consisting of:
(a) one or more black infrared reflective pigments having a percent reflectance measured in white portland cement at 1000 nanometers of at least 40%, the pigment being selected from the group consisting of manganese-vanadium oxide spinels, chromium green-black hematites, chromium iron oxides, aluminum- and titanium-doped chromium green-black modified hematites, iron chromite brown spinels, manganese ferrite spinels, chromium iron nickel black spinels, perylene blacks, and combinations thereof;(b) one or more red infrared reflective pigments having a percent reflectance measured in white portland cement at 1000 nanometers of at least 60%;(c) one or more orange to yellow infrared reflective pigments having a percent reflectance measured in white portland cement at 1000 nanometers of at least 65%, the pigment being selected from the group consisting of benzimidazolone blends, o-dianisidine coupled with aceto-acetanilides, dinitraniline coupled with beta-naphthols, isoindoline yellows, o-(2-methoxy-4-nitrophenylhydrazono)-α-aceto-2′-methoxyacetanilides, monoarylide yellows, m-nitro-o-anisidine coupled with acetoacet-o-anisidines, potassium cerium sulfides, pyrazolo-quinazolones, quinophthalone yellows, nickel antimony titanate rutile, chromium antimony titanate rutile, and combinations thereof;(d) one or more beige to brown infrared reflective pigments having a percent reflectance measured in white portland cement at 1000 nanometers of at least 60%;(e) one or more green infrared reflective pigments having a percent reflectance measured in white portland cement at 1000 nanometers of at least 60%, the pigment being selected from the group consisting of chromium hematites, chromium green-black modified hematites, cobalt chromite spinels, cobalt titanate spinels, and combinations thereof;(f) one or more blue infrared reflective pigments having a percent reflectance measured in white portland cement at 1000 nanometers of at least 50%; and(g) one or more gray to white infrared reflective pigments having a percent reflectance measured in white portland cement at 1000 nanometers of at least 60%;wherein colored concrete formed from the high-SRI cementitious system has an SRI value of at least 29 SRI units. |
