Structural lightweight concrete with superior thermal insulation

Patent metadata

Field	Value
Publication number	US-10308553-B2
Application number	US-201615084653-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 30, 2016
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A structural lightweight concrete composition comprising cement, a fine aggregate such as sand, a natural coarse aggregates, such as limestone, scoria or perlite or mixtures thereof, a synthetic coarse aggregate comprising a polymeric material, such as polypropylene beads, an industrial waste byproduct in the form of fine particles, such as silica fume or heavy oil ash, a superplasticizer, such as a polycarboxylate ether and water demonstrating lower thermal conductivity and sufficient compressive strength. Concrete products made therefrom and methods for producing such products are also provided.

First claim

The invention claimed is:

1. A structural lightweight concrete composition, comprising:
cement;
a fine aggregate;
a natural coarse aggregate;
spherical polymeric beads;
an industrial waste byproduct in the form of fine particles;
a superplasticizer; and
water;
wherein the average particle size of the fine aggregate and the industrial waste byproduct is less than or equal to 1 mm and the average particle size of the spherical polymeric beads and the natural coarse aggregate is greater than 1 mm;
wherein the weight ratio of water to cement is in the range of 0.33 to 0.8 and is sufficient to affect hydraulic setting of the cement; and
wherein the spherical polymeric beads have a specific gravity of 0.8-0.95.

2. The structural lightweight concrete composition of claim 1 , wherein the spherical polymeric beads are spherical polypropylene beads with an average particle size of 4-15 mm.

3. The structural lightweight concrete composition of claim 1 , which has a weight percentage of the spherical polymeric beads ranging from 2-15% relative to the total weight of the composition.

4. The structural lightweight concrete composition of claim 1 , wherein the cement is present in the composition at 300-500 kg/m 3 .

5. The structural lightweight concrete composition of claim 1 , which has a weight percentage of cement ranging from 20-30% relative to the total weight of the composition.

6. The structural lightweight concrete composition of claim 1 , wherein the fine aggregate is sand with an average particle size of less than 700 μm.

7. The structural lightweight concrete composition of claim 1 , which has a weight percentage of the fine aggregate ranging from 15-30% relative to the total weight of the composition.

8. The structural lightweight concrete composition of claim 1 , wherein the natural coarse aggregate is at least one selected from the group consisting of limestone, perlite, and scoria.

9. The structural lightweight concrete composition of claim 1 , which has a weight percentage of the natural coarse aggregate ranging from 20-45% relative to the total weight of the composition.

10. The structural lightweight concrete composition of claim 1 , wherein the natural coarse aggregate comprises crushed limestone having an average particle size in the range of 1-20 mm.

11. The structural lightweight concrete composition of claim 1 , wherein the industrial waste byproduct is at least one selected from the group consisting of silica fume and heavy oil ash.

12. The structural lightweight concrete composition of claim 1 , which has a weight percentage of the industrial waste byproduct in the form of fine particles ranging from 0.5-10% relative to the total weight of the composition.

13. The structural lightweight concrete composition of claim 1 , wherein the superplasticizer is a polycarboxylate ether.

14. The structural lightweight concrete composition of claim 1 , which has a weight percentage of the superplasticizer ranging from 0.1-2.0% relative to the total weight of the composition.

15. The structural lightweight concrete composition of claim 1 , which has a weight percentage of water ranging from 10-20% relative to the total weight of the composition.

16. The structural lightweight concrete composition of claim 1 , which has a 28-day unit weight in the range of 1600-1900 kg/m 3 after setting.

17. The structural lightweight concrete composition of claim 1 , which has a compressive strength in the range of 20-26 MPa after setting.

18. The structural lightweight concrete composition of claim 1 , which has a thermal conductivity in the range of 0.3-0.7 W/(m·K) after setting.

19. A method for producing a cast concrete product comprising the structural lightweight concrete composition of claim 1 , the method comprising:
mixing the cement, the fine aggregate, the natural coarse aggregate, the spherical polymeric beads and the industrial waste byproduct in the form of fine particles to form a solid cement mixture;
adding water and a superplasticizer to the cement mixture to affect hydraulic setting while maintaining a slump in the range of 50-100 mm to form a fluid concrete mixture;
casting the concrete mixture in a predetermined shape by placing the fluid concrete mixture in a mold to produce a cast concrete product after setting.

20. A cast concrete product comprising the structural lightweight concrete composition of claim 1 .

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Maslehuddin Mohammed
• Al-Dulaijan Salah U
• Ali Mohammed Rizwan
• Nasr Mahmoud

Classifications

• C04B2201/32

  for the thermal conductivity, e.g. K-factors · CPC title

• C04B28/006

  containing mineral polymers, e.g. geopolymers of the Davidovits type · CPC title

• C04B28/08

  Slag cements · CPC title

• C04B2111/40

  Porous or lightweight materials · CPC title

• C04B28/10

  Lime cements or magnesium oxide cements · CPC title