Method of placing concrete

1. A method of placing a light weighted concrete compositions comprising:

a) combining ingredients comprising 3-40 volume percent cement, 5-50 volume percent fine aggregate, 1.5-50 volume percent coarse aggregate, and 10-22 volume percent water to form a concrete mixture;

b) during or after (a), adding 5-40 volume percent of prepuff particles to the concrete mixture to form a light weighted concrete composition; and

c) pumping the light weighted concrete composition to a point higher in elevation than the delivery point of the concrete to place the concrete;

wherein the light weighted concrete composition contains less than 30 volume percent of other light weighting aggregates;

wherein the prepuff particles have an average particle diameter of from 0.2 mm to 8 mm, a bulk density of from 0.02 g/cc to 0.64 g/cc, an aspect ratio of from 1 to 3;

wherein the slump value of the placed light weighted concrete composition measured according to ASTM C 143 is greater than 1 inch; and

wherein the light weighted concrete composition has a density of from about 40 to about 135 lb./ft 3 .

2. The method according to claim 1 , wherein the prepuff particles have a substantially continuous outer layer.

3. The method according to claim 1 , wherein the prepuff particles comprise expanded polymer particles comprising one or more polymers selected from the group consisting of homopolymers of vinyl aromatic monomers; copolymers of at least one vinyl aromatic monomer with one or more of divinylbenzene, conjugated dienes, alkyl methacrylates, alkyl acrylates, acrylonitrile, and/or maleic anhydride; polyolefins; polycarbonates; polyesters; polyamides; natural rubbers; synthetic rubbers; and combinations thereof.

4. The method according to claim 1 , wherein the cement comprises one or more materials selected from the group consisting of Portland cements, pozzolana cements, gypsum cements, gypsum compositions, aluminous cements, magnesia cements, silica cements, slag cements, Type I cement, Type IA cement, Type II cement, Type IIA cement, Type III cement, Type IIIA cement, Type IV cement and Type V cement.

5. The method according to claim 1 , wherein the coarse aggregate is selected from the group consisting of stone, gravel, glass, expanded slate, clay; pumice, perlite, vermiculite, scoria, diatomite, expanded shale, expanded clay, expanded slag, pelletized aggregate, extruded fly ash, tuff, macrolite, slate, expanded blast furnace slag, sintered fly ash, coal cinders, and combinations thereof.

6. The method according to claim 1 , wherein the concrete mixture comprises one or more supplementary cementitious materials.

7. The method according to claim 1 , wherein the concrete mixture contains one or more materials selected from the group consisting of plasticizers, fibers, supplementary cementitious materials and pozzalans.

8. The method according to claim 7 , wherein the fibers are selected from the group consisting of glass fibers, silicon carbide, aramid fibers, polyester, carbon fibers, composite fibers, fiberglass, combinations thereof, fabric containing said fibers, and fabric containing combinations of said fibers.

9. The method according to claim 1 , wherein the fine aggregate is selected from the group consisting of sand, glass, pumice, perlite, vermiculite, coal cinders, and combinations thereof.

10. The method according to claim 1 , wherein the concrete mixture has a slump value measured according to ASTM C 143 of from 2 to 16 inches.

11. The method according to claim 1 , wherein after the concrete mixture is set for 28 days, has a compressive strength of at least 1400 psi as tested according to ASTM C39.

12. The method according to claim 1 , wherein the prepuff particles are aged prior to being added to the aqueous cement slurry.