An investment powder which is safer than conventional powders comprising tricalcium phosphate, and being substantially or entirely free of free silica in the respiratory portion yet providing an overall expansion at 750° C. of 1% or higher sufficient to prevent mould cracking during casting. A method of making a casting comprising forming a slurry by mixing a gypsum bonded investment powder with water, pouring the slurry into a stainless steel flask around a low melting point material model, allowing the slurry to set to define a mould, heating the mould to burn out the model and casting material into the mould wherein the stainless steel flask consists of a 400 series martensitic stainless steel.

A method of sealing propagating cracks in a sensor-laden cement sheath comprising the steps of monitoring an electrical resistivity of the sensor-laden cement sheath to produce a measured value, wherein the sensor-laden cement sheath comprises a conductive sensor, an on-demand expanding agent, and a cement, activating a heat source when the measured value of the electrical resistivity is greater than an activation threshold, increasing a temperature of the sensor-laden cement sheath with the heat source to an activation temperature, wherein the activation temperature is operable to initiate a reaction between the on-demand expanding agent and water, wherein the activation temperature is greater than a formation temperature, reacting the on-demand expanding agent with water to produce a swelled agent, wherein the swelled agent occupies a greater volume than the on-demand expanding agent, and sealing the propagating cracks in the sensor-laden cement sheath with the swelled agent.

A method of sealing propagating cracks in a sensor-laden cement sheath comprising the steps of monitoring an electrical resistivity of the sensor-laden cement sheath to produce a measured value, wherein the sensor-laden cement sheath comprises a conductive sensor, an on-demand expanding agent, and a cement, activating a heat source when the measured value of the electrical resistivity is greater than an activation threshold, increasing a temperature of the sensor-laden cement sheath with the heat source to an activation temperature, wherein the activation temperature is operable to initiate a reaction between the on-demand expanding agent and water, wherein the activation temperature is greater than a formation temperature, reacting the on-demand expanding agent with water to produce a swelled agent, wherein the swelled agent occupies a greater volume than the on-demand expanding agent, and sealing the propagating cracks in the sensor-laden cement sheath with the swelled agent.

The present invention discloses a preparation method for a surface molding film of a PVC-based stone plastic composite board, including: surface activation treatment of the PVC-based stone plastic composite board: preparation of an activated putty, coarse roughening of a substrate surface, application and solidification of the activated putty, and fine roughening of the substrate surface; preparation of a PMMA slurry; and surface film forming of the PVC-based stone plastic composite board. The PVC-based stone plastic composite board coated with a PMMA film is obtained by cold pressing and shaping in a mold, tightening up a clamp, solidifying at low temperature, treating at high temperature, cooling and demolding. The PVC-based stone plastic composite board coated with the PMMA film prepared by the present invention can avoid the problems of large investment in production lines and equipment and high production costs involved in the production of floorboards by the conventional surface printing and surface laminating technologies, to partially replace composite floorboards, stone, acrylic panels, and curtain wall panels, etc. currently popular in the market, and provide a new path for the high additional utilization of waste.

The present invention discloses a preparation method for a surface molding film of a PVC-based stone plastic composite board, including: surface activation treatment of the PVC-based stone plastic composite board: preparation of an activated putty, coarse roughening of a substrate surface, application and solidification of the activated putty, and fine roughening of the substrate surface; preparation of a PMMA slurry; and surface film forming of the PVC-based stone plastic composite board. The PVC-based stone plastic composite board coated with a PMMA film is obtained by cold pressing and shaping in a mold, tightening up a clamp, solidifying at low temperature, treating at high temperature, cooling and demolding. The PVC-based stone plastic composite board coated with the PMMA film prepared by the present invention can avoid the problems of large investment in production lines and equipment and high production costs involved in the production of floorboards by the conventional surface printing and surface laminating technologies, to partially replace composite floorboards, stone, acrylic panels, and curtain wall panels, etc. currently popular in the market, and provide a new path for the high additional utilization of waste.

A high performance concrete composition comprising: (i) at least one Class C fly ash, (ii) at least one calcium aluminate cement, (iii) at least one aggregate, and (iv) water.

An admixture for making a high-strength concrete with any type of water, including potable water, freshwater, saltwater, brackish water, reclaimed water or any other non-potable water. The admixture consists of basalt fibers, graphene nanoplatelets, calcium sulfide, calcium chloride, magnesium oxide and nanoclays. The admixture can be added to the cement to supplement it to increase the overall compressive strength, or the amount of cement used can be reduced by the amount of admixture added to shorten cure times. A concrete mix can also be prepared by replacing the calcium chloride with silica fume, reducing the amount of cement used, and introducing locally sourced aggregates, coarse and fine, to yield Ultra High Performance Concrete. Products made from the concrete incorporating the admixture have increased compression strength, improved cure times, reduced water consumption and corrosion, increased durability and workability, drastically reduced freeze-thaw effects, and superior crack control.

An admixture for making a high-strength concrete with any type of water, including potable water, freshwater, saltwater, brackish water, reclaimed water or any other non-potable water. The admixture consists of basalt fibers, graphene nanoplatelets, calcium sulfide, calcium chloride, magnesium oxide and nanoclays. The admixture can be added to the cement to supplement it to increase the overall compressive strength, or the amount of cement used can be reduced by the amount of admixture added to shorten cure times. A concrete mix can also be prepared by replacing the calcium chloride with silica fume, reducing the amount of cement used, and introducing locally sourced aggregates, coarse and fine, to yield Ultra High Performance Concrete. Products made from the concrete incorporating the admixture have increased compression strength, improved cure times, reduced water consumption and corrosion, increased durability and workability, drastically reduced freeze-thaw effects, and superior crack control.

A method of producing a carbonated composite material includes: providing a carbonatable cementitious material in particulate form; mixing the carbonatable cementitious material with water to produce a mix; forming a predetermined shape with the mix, wherein the predetermined shape has an initial pore structure containing an initial pore solution having a first pH; pre-conditioning the predetermined shape to remove a predetermined amount of the water from the predetermined shape to produce a pre-conditioned shape; carbonating the pre-conditioned shape in an environment comprising carbon dioxide to produce a modified pore structure containing a modified pore solution having and a second pH, wherein the difference between the first pH and the second pH is represented by a ΔpH, and the ΔpH is 1.0 or less.

A method of producing a carbonated composite material includes: providing a carbonatable cementitious material in particulate form; mixing the carbonatable cementitious material with water to produce a mix; forming a predetermined shape with the mix, wherein the predetermined shape has an initial pore structure containing an initial pore solution having a first pH; pre-conditioning the predetermined shape to remove a predetermined amount of the water from the predetermined shape to produce a pre-conditioned shape; carbonating the pre-conditioned shape in an environment comprising carbon dioxide to produce a modified pore structure containing a modified pore solution having and a second pH, wherein the difference between the first pH and the second pH is represented by a ΔpH, and the ΔpH is 1.0 or less.