Concrete composition for use in construction and methods of applying the same
A concrete composition for use in construction that is free of cement includes calcium sulfate hemihydrate (CSH), polypropylene (PP) fiber, sand, retarders, and superplasticizers. The retarders include poly condensed amino acid and calcium (Ca) salt. The superplasticizers include specially formulated polycarboxylate powder. Further, a method of using the concrete composition in one or more construction related activities (e.g., architectural applications) includes adding the concrete composition to water in a mixer, the concrete composition including CSH, PP fiber, sand, a retarder, and a superplasticizer; and blending the concrete composition with water in the mixer for a first predetermined amount of time. The method further includes mixing the concrete composition with water at a predetermined sheer in the mixer for a second predetermined amount of time. The method excludes the steps of steam curing, accelerated curing, and water curing that are used in conventional solutions.
1. A concrete composition for use in construction, comprising:
calcium sulfate hemihydrate (CSH), a quantity of the CSH is between 40-60% of the concrete composition by weight;
polypropylene (PP) fiber, a quantity of the PP fiber is between 4-5 lb/yd 3 ;
sand, a quantity of the sand is between 30-50% of the concrete composition by weight;
a retarder comprising poly condensed amino acid and calcium (Ca) salt, a quantity of the retarder is between 0.001-0.01% of the CSH by weight; and
a superplasticizer comprising polycarboxylate powder, a quantity of the superplasticizer is between 0.5-2% of the CSH by weight.
2. The concrete composition of claim 1 , wherein amounts of one or more of: the CSH, the PP fiber, the sand, the retarder, and the superplasticizer correspond to an initial setting time of the concrete composition, and wherein the initial setting time corresponds to a minimum hardness rating of the concrete composition.
3. The concrete composition of claim 1 , wherein amounts of one or more of: the CSH, the PP fiber, the sand, the retarder, and the superplasticizer correspond to a final setting time of the concrete composition, and wherein the final setting time corresponds to a time when the concrete composition loses its plasticity by a first amount.
4. The concrete composition of claim 1 , wherein properties of the concrete composition comprise one or more of:
a compressive strength of at least 50 N/mm 2 ;
a flexural strength of at least 15 N/mm 2 ;
an initial setting time of between 45 to 60 minutes;
a fire rating of Class A1 or better;
a thermal conductivity of 0.25 W/m·K or less;
a range of early strengths;
a range of setting times; and
free from shrinkage cracks.
5. The concrete composition of claim 1 , further comprising water in an amount such that a flowable consistency of the concrete composition is within a workable range.
6. The concrete composition of claim 1 , wherein the concrete composition is cement-free.
7. The concrete composition of claim 1 , wherein the specially formulated polycarboxylate powder is a water-reducing powder additive for use in concrete and mortar.
8. A method of using concrete composition in one or more construction activities, the method comprising:
adding the concrete composition to water in a mixer, wherein the concrete composition comprises from 40 to 60 wt. % of calcium sulfate hemihydrate (CSH), from 4 to 5 lbs/yd 3 of polypropylene (PP) fiber, from 30 to 50 wt. % of sand, a retarder, and a superplasticizer, wherein the retarder comprises poly condensed amino acid and calcium (Ca) salt and a quantity of the retarder is between 0.001-0.01% of the CSH by weight, and wherein the superplasticizer comprises polycarboxylate powder and a quantity of the superplasticizer is between 0.5-2% of the CSH by weight;
blending the concrete composition with water in the mixer for a first amount of time; and
mixing the concrete composition with water in the mixer for a second amount of time to produce a concrete mix having a workable consistency.
9. The method of claim 8 , wherein amounts of one or more of: the CSH, the PP fibers, the sand, the retarder, and the superplasticizer correspond to an initial setting time of the concrete composition, wherein the initial setting time corresponds to a minimum hardness rating of the concrete composition, and wherein during the initial setting time, the concrete composition changes from a plastic state to a solid state.
10. The method of claim 8 , wherein amounts of one or more of: the CSH, the PP fiber, the sand, the retarder, and the superplasticizer correspond to a final setting time of the concrete composition, and wherein the final setting time corresponds to a time when the concrete composition loses its plasticity by a first amount.
11. The method of claim 8 , wherein properties of the concrete composition comprise one or more of:
a compressive strength of at least 50 N/mm 2 ;
a flexural strength of at least 15 N/mm 2 ;
an initial setting time between 45 to 60 minutes;
a fire rating of Class A1 or better;
a thermal conductivity of 0.25 W/m·K or less;
a range of early strengths;
a range of setting times; and
free from shrinkage cracks.
12. The method of claim 8 , wherein water is added to the concrete composition in an amount such that a flowable consistency of the concrete composition is within a workable range.
13. The method of claim 8 , wherein the concrete composition is cement-free.
14. The method of claim 8 , further comprising air curing the mix for a period between approximately 4 to 10 days.
15. The method of claim 8 , further comprising air curing the mix for a period of approximately 7 days.
16. The method of claim 8 , wherein the first amount of time and the second amount of time are based at least in part on a type of the mixer.
17. The method of claim 8 , excludes each of steam curing, accelerated curing, and water curing.