CS272637B1 - Aluminothermic dose for run-in of reinforcement's sleeve joint - Google Patents

Abstract

The solution concerns aluminothermic content for grouting of socket joint of concrete armature. The principle of the solution consists in the fact that it consists of 15 to 25 percent by weight of atomized aluminium powder, of 50 to 60 percent by weight of iron trioxide in the form of round pellets or annealed scales in lamellas containing at most 8 percent by weight of iron oxide, of 20 to 30 percent by weight of metal scrap containing low carbon steel, of 1 to 4 percent by weight of carbonic ferromanganese, of 0.5 to 1.5 percent by weight of ferrotitanium, of 0.5 to 1.5 percent by weight of ferromolybdenum, and of 0.5 to 1.5 percent by weight of calcium.

Description

The invention relates to the composition of an aluminothermal dose for grout metal of the clamp joint of a concrete reinforcement.

The batches for casting the clamp joints of the concrete reinforcement are known abroad. Their composition is most often based on aluminum grits and oxide media or with the addition of iron oxide, preferably based on pure iron oxide 8 with aluminum powder. the alloys are not usually given. The doses are intended for casting of the clamp joints of reinforcing steel reinforcement, the yield strength of which does not exceed 420 MPa. Nowadays, concrete reinforcements of steel with a yield strength above 490 MEa are being used, for which the existing batches no longer satisfy due to low mechanical properties.

Said drawbacks of aluminothermal doses for grouting the sleeve joints of high-strength steel reinforcements eliminate to a large extent the composition of the dose according to the invention, which consists of 15 to 25% by weight. from 50 to 60% by weight of iron oxide in the form of round shot or annealed scale in slats containing not more than 8% by weight % of iron oxide, and 20 to 30 wt. % of low-carbon steel scrap, from 1 to 4 wt. % of carbon ferro-manganese, from 0.5 to 1.5 wt. % ferro molybdenum, from 0.5 to 1.5 wt. % of ferrotitanium and from 0.5 to 1.5 wt. Calc,

The aluminothermal dose according to the invention comprises iron oxide in the form of spherical shot pellets, which are the product in the recovery of hydrofluoric acid as waste. Equivalent is the iron oxide obtained by annealing the crude scale from the rolling plates in an electric or gas furnace at a temperature of 900 ° C.

The aluminothermal dose for the grout metal of the high-strength steel reinforcement sleeve joint in one case contained 16.5 wt.%, Aluminum grits, 51.8 wt.%. iron oxide, 27.1 wt.%, low-carbon steel scrap (11370), 2.5 wt.%, carbon ferro-manganese, 0.7 wt. % ferro molybdenum, 0.7 wt. ferrotitanium, 0.7 55 mass, calcia,

In a more specific case, the following aluminothermal dose for dressing was produced according to the invention, which contained 18.3 wt. aluminum grits, 55 wt. % ferric oxide, 22 wt. % of low-carbon steel scrap (11370), 2.3 wt. % of ferro-manganese, 0.8 wt. % ferrotitanium, 0.8 wt. % ferro molybdenum, 0.8 wt. Calc,

Both aluminothermal batch compositions were made by grout joints of concrete reinforcement, tested in series with a larger number of samples, showing that the mechanical properties have the same as the unreinforced concrete reinforcement material and can be used for structures with tensile strength factor Hs »1.

Claims (1)

SUBJECT MATTER An aluminothermal dose for grouting the joint joint of a concrete reinforcement, characterized in that it consists of 15 to 25 wt. from 50 to 60 wt. iron oxide in the form of round shot or annealed scale in lamellas containing not more than 8% by weight % ferrous oxide, from 20 to 30 wt. scrap of low-carbon steel, from 1 to 4% by weight, carbon ferro-manganese, from 0.5 to 1.5% by weight, ferro-titanium, from 0.5 to 1.5% by weight, ferro molybdenum, from 0.5 to 1.5% % by weight, calcia.