HYDRAULIC CEMENT AND COMPOSITION EMPLOYING THE SAME

Abstract: A hydraulic cement is formed from a Class C fly ash and an alkali metal activator. Mortar and concrete compositions can be prepared with this hydraulic cement. The cement is particularly useful in producing mortar and concrete compositions that achieve high strengths in a short time.

Description: HYDRAULIC CEMENT AND COMPOSITION EMPLOYING THE SAME BACKGROUND OF THE INVENTION Hydraulic cements, such as portland cement and blen hydraulic cements, consisting of portland cement pozzolans, have, for many years, been used as an essent ingredient of the mortar and concrete used for construct of structures, highways, etc. In many instances, fly has been used as the pozzolanic component in blen hydraulic cements, and as a mineral admixture to repl part of the more expensive portland cement used in mortar concrete. The use of fly ash, in place of part of Portland cement or as a constituent in blended ceme reduces the large amount of energy required to produce hydraulic cements required for mortar and concre However, the prior art has taught that no more than 35 to per cent of the portland cement can be replaced with ash. According to the teachings of the prior art, when m fly ash than that is employed, the resulting mortars a concretes do not have sufficient strength. It now has been found, however, according to t present invention, that a hydraulic cement where all of t Portland cement or blended hydraulic cement is replaced wi fly ash can be formed by activating a Class C fly ash wi an alkali metal containing material. There is, cons quently, a further reduction of cost and energy requir ments. -2- BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, a hydraul cement composition is provided consisting essentially Class C. fly ash and an alkali metal activator. The ac ivator consists of one or more materials selected from t class consisting of potassium hydroxide, potassium carbo ate, sodium hydroxide, sodium carbonate and portla cementkiln dust. The amount of alkaline metal activat employed, per 100 parts of the total composition, can va from about 1/2 to 10 parts, by weight. In general, when o of the listed materials other than portland cement kiln du is employed, no more than 4 parts by weight are use preferably, between 1/2 and 3 parts, by weight. Included in the formulation are appropriate set contr materials such as citric acid, borax, Cormi-x, WRDA, Darac 100, or other admixtures commonly used in concrete formul tions. The admixture should comprise from about 1/2 to parts, by weight, of at least one of the referenc ' materials per 100 total parts of cement composition. This hydraulic cement achieves both high ear strengths and high ultimate strengths. It can be utiliz for rapid concrete repair or construction. This cement ca be utilized in the production of precast and prestresse concrete, with or without heat curing. The cement composition of the present inventio includes the following components, by weight: From 90 to 97 parts Class C fly ash From 1/2 to 10 parts alkali metal activator From 1/2 to 3 parts admixture In addition to the materials in the above formulation, othe materials can be added to the composition, as, for example retarders and water reducers commonly used in concret formulations. Various substitutions are also possible for -3- the required materials. While potassium hydroxide is preferred alkaline metal activator, sodium hydroxide, sod carbonate, potassium carbonate, and portland cement k stack dust can replace all or part of the potass hydroxide. As indicated, when any of the referen materials other than portland cement kiln stack dust employed, the amount of material is generally from 1/2 to parts, by weight, for each 100 part of the cement compos tion, preferably from about 1/2 to 3 parts, by weight. When the hydraulic cement of the present invention used in concrete or mortar, the resulting hardened materi has sufficient strength that it can be put into service few hours after being placed. This strength can be obtain with or without heat curing. DESCRIPTION OF PREFERRED EMBODIMENTS The hydraulic cement of the present invention has, previously indicated, the following components by weight: 90 to 97 parts Class C fly ash 1/2 to 10 parts alkali metal activator 1/2 to 3 parts admixture The fly ash is a Class C fly ash as classified in ASTM 618. When potassium hydroxide is used as the alkali met activator, it can be in the form of flakes, pellets, o water solution. Sodium hydroxide, potassium carbonate sodium carbonate, and high alkali kiln stack dusts, such a those collected during the production of portland cement can also be utilized as a source of alkali metal ions. A preferred admixture is citric acid which can be i any available grade, such as fine crystal, powder, o liquid. Salts of citric acid can be used. -4- Borax, a mineral with the compositi a 2 0.2B2θ3.10H2θ. , can be used in any available grade a can be replaced, all or in part, by other available a mixtures that control the set of concrete mixtures. T major distinction between the cement of the present inve tion and prior art is the use of fly ash with an alka metal activator to produce a hydraulic cement with ve early strengths, and without portland cement. All of the - components can be interground or inte blended and used as a complete cement without addition admixtures. In an alternative, the sources of the alka metal ion, citric acid, and borax, or other admixtures, m be added at the concrete mixer, in a dry or liquid form, an admixture or as a second component. When all of .t materials are blended together, so that only water a aggregate are required to obtain a mortar or concrete, t control problems that can occur when materials are mixed the field are eliminated or minimized. On the other han when the various materials are blended in the field, the is an economy of storage and shipping. In addition, the t component procedure does allow for greater control working time. The following are given as examples of formulations the hydraulic cement of the present invention. They shou be considered only as illustrative and not as limiting, any way, the full scope of the invention as covered in t appended claims. All parts are by weigh The Class C fly ash used in the following examples had t properties set forth below: -5- CLASS C FLY ASH CHEMICAL ANALYSIS (AS RECEIVED %) Si0 2 37.60 A1 2 0 3 20.47 Fe 2 03 5.44 CaO 21.54 MgO 4.61 S0 3 (by LECO Furnace 2.12%) 1.71 Na 2 0 2.78 K 2 0 0.52 Ti0 2 1.05 SrO 0.65 Loss , 0.41 FINENESS SIEVE No. 325 = 82.3% passing BLAINE = 4270 cm 2 /g X-RAY DIFFRACTION - CRYSTAL STRUCTURES PRESENT: 1) Si0 2 (silicon oxide) 2) Fe 2 03 (iron oxide) 3) MgO (magnesium oxide) 4) CaO (calcium oxide) 5) Ti0 2 (titanium oxide) EXAMPLE 1 A cement mixture was formed consisting of: 96.29 parts Class C fly ash 1.41 parts potassium hydroxide 1.28 parts citric acid 1.02 parts borax -6- EXAMPLE 2 A concrete was prepared employing the cement of Exampl 1 and other necessary materials as indicated below: 825 parts of cement as Example 1 1213 parts sand 1820 parts gravel 142 parts water The various materials were mixed in a concrete mixer. Th concrete had an open or working time of 25 minutes. Part o the concrete was cast in molds and cured at ambient tempera ture (73°F). This concrete had compressive strengths a follows: Age Strength 3 hours 1,800 psi 4 hours 2,000 psi 1 day .. 4,000 psi 3 days t 6,600 psi 7 days 8,800 psi 28 days 10,400 psi The remaining concrete was cast in molds and stored a ambient temperature (73 β F) for one hour, then cured in stea at 195°F for one and one-half hours. Specimens were the cured in ambient (73 β F) air until tested. This concrete ha compressive strengths as follows: Age Strength " 3 hours 3,600 psi 4 hours 4,800 psi 1 day 5,700 psi 3 days 6,600 psi 7 days 7,600 psi 28 days 9,400 psi -7- EXAMPLE 3 A cement mixture was formed consisting of: 95.98 parts Class C fly ash 1.40 parts potassium hydroxide 1.28 parts citric acid 1.02 parts borax 0.05 part Cormix SP-IP Cormix 2000 SP-IP is a sodium salt of a copolymer of unsaturated carboxylic acid and the hydroxyaklyl ester such an acid. Cormix meets the requirements of ASTM C-4 as a Type G admixture (water-reducing, high range, a retarding admixture) . EXAMPLE 4 A concrete was prepared employing the cement of Examp 3 and other necessary materials as indicated below: 827 parts of cement of Example 3 1362 parts sand 1669 parts gravel 142 parts water The various materials were mixed in a concrete mixer. T concrete had an open or working time of 20 minutes. Part the concrete was cast in molds and cured at ambient temper ture (73 β F). This concrete had compressive strengths 2,000 psi at 4 hours, 4,200 psi at 1 day, and 7,600 psi at days. The remaining concrete was cast in molds and stored a ambient temperatures (73°F) for one hour, then cured a 195°F for one and one-half hours. Specimens were then cure in ambient (73°F) air until tested. This concrete ha compressive strengths of 5,000 psi at 4 hours, 6,500 psi a 1 day, and 7,600 psi at 7 days. EXAMPLE 5 A cement mixture was formed consisting of: 95.98 parts of Class C fly ash 1.40 parts potassium hydroxide 1.28 parts citric acid 1.02 parts borax 0.05 part Cormix 2000 cp The Cormix 2000 is the sodium salt of a copolymer of unsaturated carboxylic acid and the hydroxyalkyl ester that acid. The material meets the requirements of ASTM 494-86, as a type G admixture, one which is water-reducin high range, and retarding. EXAMPLE 6 A concrete was prepared employing the cement of Examp 5 and other necessary materials as indicated below: 827 parts of cement of Example 5 1362 parts sand 1669 parts gravel 142 parts water The various materials were mixed in a concrete mixer. Th concrete had an open or working time of 32 minutes. Part o the concrete was cast in molds and cured at ambient tempera ture (73°F). This concrete had compressive strengths o 1,300 psi at 4 hours, 2,800 psi at 1 day, and 5,5000 psi a 7 days. The remaining concrete was cast in molds and stored a ambient temperature (73 β F) for one hour, then cured at 195° for one and one-half hours. Specimens were then cured i ambient (73°F) air until tested. This concrete had compres sive strengths of 2,200 psi at 4 hours, 3,200 psi at 1 day and 4,500 psi at 7 days. -9- EXAMPLE 7 A cement mixture was made consisting of: 95.98 parts Class C fly ash 1.40 parts potassium hydroxide 1.28 parts citric acid 1.02 parts borax 0.05 part WRDA-79P WRDA 79-P is a modified lignosulfonate, with catalyst. meets the requirements of ASTM C-494 as a Type A admi (water-reducing admixture) and Type D admixture (wa reducing and retarding admixture) . EXAMPLE 8 A concrete was prepared employing the cement of Exa 7 and other necessary materials as indicated below: 827 parts of cement of Example 7 1362 parts sand 1669 parts gravel 142 parts water The various materials were mixed in a concrete mixer. concrete had an open or working time of 28 minutes. Par the concrete was cast in molds and cured at ambient tempe ture (73 β F). This concrete had. compressive strengths 1,900 psi at 4 hours, 3,600 psi at l day, and 7,600 psi a days. The remaining concrete was cast in molds and stored ambient temperatures (73 β F) for one hour, then cured 195°F for one and one-half hours. Specimens were then cu in ambient (73°F) air until tested. This concrete compressive strengths of 2,900 psi at 4 hours, 4,200 psi 1 day, and 5,800 psi at 7 days. EXAMPLE 9 A cement mixture was made consisting of: 95.98 parts Class C fly ash 1.40 parts potassium hydroxide 1.28 parts citric acid 1.02 parts borax 0.05 part Daracem 100P Daracem 100P is a dispersion of sulfonated napthalen formaldehyde condensate, a gluconate, and a lignosulfonate Daracem 100P meets the requirements of ASTM C-494 as a Typ G admixture (water-reducing high . range, and retardin admixture) . EXAMPLE 10 A concrete was prepared employing the cement of Exampl 9 and other necessary materials as indicated below: 827 parts of cement of Example 9 1362 parts sand 1669 parts gravel 142 parts water The various materials were mixed in a concrete mixer. Th concrete had an open or working time of 30 minutes. Part o the concrete was cast in molds and cured at ambient tempera ture (73°F). This concrete had compressive strengths o 1,900 psi at 4 hours, 3,800 psi at 1 day, and__7,700 psi at days. The remaining concrete was cast in molds and stored a ambient temperature (73°F) for one hour, then cured at 195 β for one and one-half hours. Specimens were then cured i ambient (73 β F) air until tested. This concrete had compres sive strengths of 3,800 psi at 4 hours, 4,900 psi at 1 day, and 6,200 psi at 7 days. -11- EXAMPLE 11 A cement mixture was made consisting of: 95.98 parts Class C fly ash 1.40 parts potassium hydroxide 1.28 parts citric acid 1.02 parts borax 0.025 part Cormix 2000 cp 0.025 part Cormix SP-IP EXAMPLE 12 A concrete was prepared employing the cement of Exam 11 and other necessary materials as indicated below: 827 parts of cement of Example 11 1362 parts sand 1669 parts gravel 142 parts watet The various materials were mixed in a concrete mixer. concrete had an open or working time of 25 minutes. Part the concrete was cast in molds and cured at ambient tempe ture (73°F). This concrete had compressive strengths 2,400 psi at 4 hours and 5,000 psi at 1 day. The remaining concrete was cast in molds and stored ambient temperature (73 β F) for onejhour, then cured at 195 for one and one-half hours. Specimens were then cured ambient (73°F) air until tested. This concrete had compre sive strengths of 5,100 psi at 4 hours and 7,300 psi at day. ~ EXAMPLE 13 A mortar was prepared employing the cement of Example and other necessary materials as indicated below: 1480 parts of the cement of Example 1 2274 parts sand 246 parts water -12- The various materials were mixed in a mortar mixer. T mortar had an open or working time of 30 minutes. Part the mortar was cast in molds and cured at ambient temper ortar had compressive strengths Strength 2,000 psi 2,300 psi 2,700 psi 5,400 psi 8,400 psi 10,000 psi 13,200 psi The remaining mortar was cast in molds and stored at ambie temperature (73°F) for one hour, then cured at 195 β F for o and one-half hours. Specimens were then cured in ambie (73°F) air until tested. This mortar had compressi strengths as follows: Age Strength 4 hours 4,400 psi 1 day 5,800 psi 28 days 12,800 psi EXAMPLE 14 A cement mixture was made consisting of: 96.41 parts Class C fly ash 1.28 parts potassium hydroxide 1.28 parts citric acid 1.03 parts borax EXAMPLE 15 A mortar was prepared employing the cement of Exampl 4 and other necessary materials as indicated below: 1479 parts of the cement of Example 14 2275 parts sand 246 parts water -13- The various materials were mixed in a mortar mixer. mortar had an open or working time of 37 minutes. Part the mortar was cast in molds and cured at ambient tempe tures (73°F). This mortar had compressive strengths follows: Age Strength 2 hours 1,800 psi 3 hours 2,200 psi 4 hours 2,400 psi 1 day 4,700 psi 3 days 7,400 psi 7 days 8,500 psi 28 days 12,000 psi The remaining mortar was cast in molds and stored at ambi temperature (73 β F) for one hour, then cured at 195 β F for o and one-half hours. Specimens were then cured in ambie (73°F) air until tested. This mortar had compressi strengths as follows: Age Strength 4 hours 3,400 psi 1 day 5,000 psi 28 days ' 12,000 psi EXAMPLE 16 A cement mixture was made consisting of: 96.53 parts Class C fly ash 1.16 parts potassium hydroxide 1.28 parts citric acid 1.03 parts borax -14- EXAMPLE 17 A mortar was prepared employing the cement of Example 16 and other necessary materials as indicated below: 1477 parts of the cement of Example 16 2276 parts sand 247 parts water The various materials were mixed in a mortar mixer. The mortar had an open or working time of 45 minutes. Part of the mortar was cast in molds and cured at ambient tempera- mortar had compressive strengths as Strength 1,500 psi 2,000 psi 2,200 psi 4,200 psi 6,600 psi 8,300 psi 11,700 psi The remaining mortar was cast in molds and stored at ambient temperature (73 β F) for one hour, then cured at 195 β F for one and one-half hours. Specimens were then cured in ambient ( 73 β F) air until tested. This mortar had compressive strengths as follows: Age Strength 4 hours 3,100 psi 1 day 5,200 psi 28 days 11,100 psi -15- EXAMPLE 18 A cement mixture was prepared consisting of: 96.66 parts Class C fly ash 1.03 parts potassium hydroxide 1.28 parts citric acid 1.03 parts borax EXAMPLE 19 A mortar was prepared employing the cement of Exam 18 and other necessary materials as indicated below: 1476 parts of the cement of Example 18 2277 parts sand 247 parts water The various materials were mixed in a mortar mixer. mortar had an open or working time of 60 minutes. Part the mortar was cast in molds and cured at ambient tempe ture (73 β F). This mortar had compressive strengths follows: Age Strength 2 hours 1,300 psi 3 hours 1,800 psi 4 hours 2,200 psi 1 day 4,000 psi 3 days 6,300 psi 7 days 8,200 psi 28 days 11,700 psi The remaining mortar was cast in molds and stored at ambie temperature (73 β F) for one hour, then cured at 195 β F for o and one-half hours. Specimens were then cured in ambie (73 Q F) air until tested. This mortar had compressi strengths as follows: -16- A cement mixture was prepared consisting of: 96.79 parts Class C fly ash 0.90 part potassium hydroxide 1.28 parts citric acid 1.03 parts borax EXAMPLE 21 A mortar was prepared employing the cement of Examp 20 and other necessary materials as indicated below: 1475 parts of the cement of Example 20 2278 parts sand 247 parts water The various materials were mixed in a mortar mixer. T mortar had an open or working time of 110 minutes. Part the mortar was cast in molds and cured at ambient temper mortar had compressive strengths Strength 160 psi 1,200 psi 1,600 psi 3,600 psi 5,400 psi 6,900 psi 9,700 psi -17- The remaining mortar was cast in molds and stored at ambi temperature (73°F) for one hour, then cured at 195°F for and one-half hours. Specimens were then cured in ambi (73°F) air until tested. This mortar had compress strengths as follows: Age Strength 4 hours 2,000 psi 1 day 5,000 psi 28 days 9,900 psi EXAMPLE 22 A cement mixture was prepared. consisting of: 96.91 parts Class C fly ash 0.77 part potassium hydroxide 1.28 parts citric acid 1.03 parts borax EXAMPLE 23 A mortar was prepared employing the cement of Examp 22 and other necessary materials as indicated below: 1474 parts of the cement of Example 22 2279 parts sand 247 parts water The various materials were mixed in a mortar mixer. T mortar had an open or working time of 135 minutes. Part o the mortar was cast in molds and cured at ambient tempera ture (73°F). This mortar had compressive strengths a follows: Age Strength 2 hours not set 3 hours 640 psi 4 hours 1,400 psi 1 day 3,100 psi 3 days 4,900 psi 7 days 5,500 psi -18- The remaining mortar was cast in molds and stored at ambie temperature (73°F) for one hour, then cured at 195°F for o and one-half hours. Specimens were then cured in ambie (73 β F) air until tested. The mortar had compressi strengths as follows: Age Strength 4 hours 1,000 psi 1 day 3,100 psi 28 days 7,900 psi EXAMPLE 24 A mortar was prepared as in Example 19 and cast i molds at ambient temperature (73 β F). The specimens wer cooled at 5 β F " and maintained- at that temperature unti shortly before testing. At that time the specimens wer warmed to 73 β F and tested for compressive strength. Th mortar had strengths of 700 psi at 4 hours, 1,200 psi at day, 1,500 psi at 7 days, and 3,400 psi at 28 days. EXAMPLE 25 A. cement mixture was prepared consisting of: 96.91 parts Class C fly ash 0.77 part sodium hydroxide 1.29 parts citric acid 1.03 parts borax EXAMPLE 26 A mortar was prepared employing the cement of Exampl 25 and other necessary materials as indicated below: 1467 parts of the cement of Example 25 2268 parts sand 265 parts water -19- The various materials were mixed in a mortar mixer. mortar had an open or working time of 40 minutes. mortar was cast in molds and cured at ambient temperatu (73°F). This mortar had compressive strengths of 1,700 at 2 hours, 2,000 psi at 3 hours, 2,200 psi at 4 hours, 4,100 psi at 1 day. EXAMPLE 27 A cement mixture was prepared consisting of: 94.95 parts Class C fly ash 3.79 parts potassium carbonate 1.26 parts citric acid EXAMPLE 28 A mortar was prepared employing the cement of Examp 27 and other necessary materials as indicated below: 1482 parts cement of Example 27 2246 parts sand 272 parts water The various materials were mixed in a mortar mixer. T mortar had an open or working ime of 30 minutes. T mortar was mixed_, cast in molds and cured at ambie temperature (73°F). The mortar had compressive strengths follows: Age Strength 2 hours 1,100 psi 3 hours 1,500 psi 4 hours 1,700 psi 1 day 4,100 psi 3 days 5,800 psi 7 days 8,400 psi -20- EXAMPLE 29 A cement mixture was prepared consisting of: 90.69 parts Class C fly ash 7.98 parts kiln stack dust 1.33 parts citric acid The kiln stack dust had the following properties: Specific Gravity = 2.63 CHEMICAL Leco S0 3 = 11.70% Atomic Absorption Na 2 0 = 2.25% Atomic Absorption K 2 0 = 25.2% Loss =• 12.25% Moisture Content = 0.57% Water Soluble Alkali: Na 2 0 = 2.1% Water Soluble Alkali: K 2 0 = 20.4% FINENESS Sieves: No. 200 = 90.5% No. 325 = 86.3% Blaine: 18,619 cm 2 /g X-RAY DIFFRACTION; CRYSTAL STRUCTURES PRESENT: 1) Calcium Carbonate-^ 2) Potassium Sulfate 3) Potassium Sodium Sulfate EXAMPLE 30 A mortar was prepared employing the cement of Exampl 9 and other necessary materials as indicated below: 1424 parts cement of Example 29 2273 parts sand 303 parts water -21- The various materials were mixed in a mortar mixer. mortar had an open or working time of 30 minutes. mortar was mixed, cast in molds and cured at ambi temperature (73°F). The mortar had compressive strengths 1,300 psi at 2 hours, 1,500 psi at 3 hours, and 1,600 psi 4 hours. EXAMPLE 31 A cement mixture was prepared consisting of: 92.02 parts Class C fly ash 6.65 parts kiln stack dust 1.33 parts citric acid EXAMPLE 32 A mortar was prepared employing the cement of Exam 31 and other necessary materials as indicated below: 1431 parts cement of Example 31 2284 parts sand 285 parts water The various materials were mixed in a mortar mixer. T mortar had an open or working time of 30 minutes. T mortar was mixed, cast in molds and cured at ambie temperature (73°F). The mortar had compressive strengths 1,200^31 at 2 hours, 1,500 psi at 3 hours, 1,800 psi at hours, and 4,000 psi at 1 day. While specific examples of the present invention ha been shown and described, they should be considered merely illustrative, and not " as limiting, in any way, t full scope of the invention as set forth in the append claims.

Claims: -22- WHAT IS CLAIMED AS NEW IS: 1. A hydraulic cement comprising, by weight: From about 90 to 97 parts Class C fly ash From about 1/2 to 10 parts alkali metal activator From about 1/2 to 3 parts admixture 2. The hydraulic cement of Claim 1 wherein the alkal metal activator is portland cement kiln dust. 3. The hydraulic cement of Claim 1 wherein the alkal metal activator is from 1/2 to 4 parts of at least on material selected from the group consisting of potassiu hydroxide,, potassium carbonate, sodium hydroxide, and sodiu carbonate. r 4. The hydraulic cement of Claim 3 wherein the amoun is from about 1/2 to 3 parts. 5. The hydraulic cement of Claim 3 wherein the alkali metal activator is potassium hydroxide. 6. The hydraulic cement of Claim 1 wherein the admixture is selected from the class consisting of citric acid, borax, Cormix, WRDA, and Daracem 100. 7. The hydraulic cement of Claim 6 wherein the admixture is from about 1/2 to 1 1/2 parts citric acid and from about 1/2 to 1 1/2 parts borax. 8. A two part composition for hydraulic ceme • wherein said two parts are blended prior to preparation the cement, comprising: a. a first part comprising from 90 to 97 parts, weight. Class C fly ash; and b. a second part comprising: (1) from about 1/2 to 10 parts alkali metal activator; and (2) from about 1/2 to 3 parts admixture. 9. The composition of Claim 8 wherein the alkali met activator is portland cement kiln dust. 10. The composition of Claim 8 wherein the alka metal activator is from 1/2 to 4 parts of at least o material selected from the group consisting of potassi hydroxide, potassium carbonate, sodium hydroxide, and sodi carbonate. 11. The composition of Claim 8 wherein the amount from about 1/2 to 3 parts. 12. The composition of Claim 8 wherein the alkal metal activator is potassium hydroxide. 13. The composition of Claim 8 wherein the admixtur is selected from the class consisting of citric acid, borax Cormix, WRDA, and Daracem 100. 14. The composition of Claim 8 wherein the admixtur is from about 1/2 to 1 1/2 parts citric acid and from abou 1/2 to 1 1/2 parts borax.

Inventors: GRAVITT BILLY B, HEITZMANN RICHARD F, SAWYER JAMES L, GRAVITT, BILLY, B., HEITZMANN, RICHARD, F., SAWYER, JAMES, L.
Applicants: LONE STAR IND INC, LONE STAR INDUSTRIES, INC.
Application year: 1988
Main classification: C04B7
IPC codes: C04B7, C04B24, C04B28