Jointing and surface compound for construction elements, its preparation process and building process of a structure

Abstract

The object of the invention is a drying compound comprising from 50 to 85% of FGD gypsum and/or natural or processed gypsum, in mass percentages based on the total mass of the compound, presenting the following particle size characteristics: (i) a d 50 from 35 to 70 μm and (ii) a span (d 90 -d 10 /d 50 ) lower than 2. The object of the invention is also a preparation process of the compound according to the invention. Finally, the object of the invention is a building process of a structure using this compound.

1 . A building process for a structure, comprising:
 obtaining a composition comprising: (a) a drying compound and (b) water;   eliminating the water from the composition;   juxtaposing gypsum boards presenting a facer; and   covering a joint between the boards using the drying compound,   wherein the drying compound comprises from 50 to 85% of a Fluid Gas Desulfuration (FGD) gypsum, in mass percentages based on the total mass of the compound, having the following particle size characteristics: (i) a d 50  from 36 to 70 μm and (ii) a span (d 90 -d 10 )/d 50  lower than 2, and the drying compound further comprises 0.5 to 20% by weight based on the total mass of the compound, of an organic binder selected from the group consisting of polyvinylic alcohol homopolymers, polyvinyl acetate homopolymers (plasticized or non plasticized), ethylene/vinyl acetate (EVA plasticized or non plasticized) copolymers, ethylene/vinyl versatate copolymers, vinyl acetate/vinyl versatate copolymers, polyacrylics, vinyl acetate/acrylics copolymers, styrenic/acrylic copolymers, styrene/butadiene copolymers, vinyl acetate/vinyl versatate/vinyl maleate terpolymers, viny acetate/vinyl versatate/acrylics terpolymers, acrylic terpolymers and mixtures thereof; and   wherein the drying compound has a density of from 1 to 1.8, a Brookfield viscosity of from 200,000 to 800,000 cps, and a pH of from 8 to 9.5.   
     
     
         2 . The process according to  claim 1 , comprising juxtaposing gypsum boards, filling a space between the boards using a filling compound, applying tape, covering the tape with the filling compound, then covering the filling compound with a finishing compound, wherein the filling and/or finishing compound is the drying compound. 
     
     
         3 . The process according to  claim 2 , wherein the filling and the finishing compound is the drying compound. 
     
     
         4 . The process according to  claim 1 , comprising juxtaposing gypsum boards, applying self-adhesive glass mesh tape, covering the tape with a filling compound, then covering the filling compound with a finishing compound, wherein the filling and/or finishing compound is the drying compound. 
     
     
         5 . The process according to  claim 1 , wherein the facer is paper and the process further comprises applying tape to the gypsum boards. 
     
     
         6 . The process according to  claim 1 , wherein the drying compound comprises from 50 to 75% of the FGD gypsum, in mass percentages based on the total mass of the compound. 
     
     
         7 . The process according to  claim 1 , wherein the drying compound further comprises a spreading agent in an amount of from 0.5 to 10% in mass percentages based on the total mass of the compound. 
     
     
         8 . The process according to  claim 1 , wherein the drying compound further comprises a spreading agent comprising a clay and/or talc and/or mica. 
     
     
         9 . The process according to  claim 1 , wherein the drying compound further comprises a workability agent that is a water-retaining agent and a thickener, in an amount of from 1 to 15% in mass percentages based on the total mass of the compound. 
     
     
         10 . The process according to  claim 1 , wherein the drying compound further comprises a workability agent that is a water-retaining agent and a thickener, the water-retaining agent being a cellulose derivative. 
     
     
         11 . The process according to  claim 1 , wherein the drying compound comprises the organic binder in an amount from 1 to 8 weight% based on the total mass of the compound. 
     
     
         12 . The process according to  claim 1 , wherein the drying compound further comprises a spreading agent in an amount of from 1 to 5% in mass percentages based on the total mass of the compound.