CS253499B1 - Gypsum-free binding agent with stabilized qualities on base of cement clinker - Google Patents

Abstract

The material is used in the construction industry. It has improved rheological properties and higher mechanical strength. The material contains: cement clinker, additives improving grinding, salts or hydroxides of alkaline metals, polyelectrolytes, regulators of the hardening process and silica with suitable amorphous structure.

Description

The invention relates to a binder with stabilized properties based on cement clinker, simply gypsum.

Without gypsum cements (hereinafter referred to as BS cements), a new type of inorganic binder is based on the synergistic effect of the action of a mixture of inorganic electrolyte (especially an alkali carbonate, bicarbonate or hydroxide) and an anionic coater (e.g. ligninsulfonate, sulionated lignin, sulfonated polyphenolate and others / The properties of these cements have been described, for example, in article F, Škvára, N. Rybinová: The gypsum-free portland cement, Cement and Concrete Research, No.6, 1985 and 198,053, 203,212, 225,066.

An important feature of these cements is that they can be treated with a low water coefficient while maintaining good theological properties. Due to the low porosity of hardened cement stone, BS cements are characterized not only by high short- and long-term strengths, but also by high corrosion resistance, low and negative temperature hardening ability and high temperature resistance / see F. Škváry, L. Pekárek, B. Velička: The gypsum-free portland cement hydration and its thermal properies, Proceedings of the 8th Inter. Conf. Thermal Analysis, 566-570 (1985).

For BS cements, high short-term strengths (1 to 24 hours) were achieved only for cements with a specific surface area higher than approx. 500 m / kg. For BS cements with a lower specific surface, strengths higher than those of conventional Portland cement were achieved after 3 to 7 days of hydration. The disadvantage of BS cements ground to specific

253 499 г surface above 500 m / kg is their relative technological unavailability. For its production, a special energy-intensive three-mill grinding machine has to be constructed (see CS). 1940,194,892 /.

In the study of BS cements with a specific surface area of less than 450e · 500 g m / kg, virtually the same quantitative dependence on the specific surface area was found as for BS cements with a higher specific surface area. For GL cements with a specific surface smaller than 450 & 500 m / kg, it was observed perioOické fluctuations in these reakttvitě Cemet, perioOické These changes were manifested in přeOevším perioOikéém / time-dependent / fluctuation of initial setting in zěáVslosti'na Oobe sklaOování _of said variation is induced By glass conditions, e.g. moistening the cemmen. This phenomenon then brought in tests c ^{I HT} cemmnt ^{of type b} will help to, or mixtures of ^I c ^{HT GL} cements ^of its mnnly Oobu zpracooaae emsi v depending on the lot Oobe atlkOovánn.

Research activities in obCassi GL cements were therefore focused on this oOstratětí íčíVOoi ^ (^ í • phenomenon. The invention is based on ^the know U, ^Z e (addition of 0.05 20% by weight ^ i. ^ ^Y Soce JEM it Armo ^ ^ o ^ ° ^г with specific surface of ^5,000 2 ^{00,000 m m} / kg ^for a ^BS cementite is poorly ^p Suji their performance, and Oochází to stabilize these vlkatιΊOsat, particularly early-ЬпиН. by adding highly fine ammorního Si02 Furthermore, one 'considerably improves The composition (eg with an anise / viscosity slurry) and strength is increased, especially for a short time.

Pps / III highly fine Si0 ₂ ammofniho Oo portknoátých ii cement concrete is known from patents and řaOy zOroj As this highly ammofního fine SiO? it serves the opaque from the meeaurgical processes, e.g. from the production of Si, FeSS, FeCr.ri, SiMn, which in high temperature processes produces SiO, which is further oxidized to SiO2. This highly fine and ^e 2 ammofní predominantly Si0 ₂ having a surface reverse to the m ^ oO Oo 5000 30000 / and the amount / m / kg as uváděěí Aïtcin P. P. Pitasníιtčk / t DM Roy article N ^ h ^ s ^ ical anO chemicaL chhar ace eistai on of conOenseO silca fumes / Am. Ceram. BuU. 63, "1487-1491, 19855th Si0 ₂ at these

253499 capture process drift as that previously greatly reduce pollution 'midst Me alur ^{e d ic h} yc veils ^d u. Olet Si ₂ ° is a very convenient source of amorphous SiO ₂ in addition to the so-called. Fumed SiO ₂ produced eg ... in the oxidation of SiCl *. The specific surface area fumed S.iO ₂ is ^{STE sentences,} but also reverse to ^{the P ú} ovrch years: ^-S u ² .and ein ° ^{and 2} to 00,000 m ^{2 / kg}

Veeikost čássic S1O2 as drift is even 100 times smaller than is ikrs ^{t e} částtic BE ^of the Joint cemmetu. 6le ^t is ^H mod ice к velikosSi čássic and physiological condition IcKnimu / ammonium form / high. reactive and acts as a highly effective additive in cement or concrete. Is reacted with tvořieem / or presence / Cca0H / 2 to produce a ^hydro-AT and ^U and the atctivně ziúčastnuje tiydratačť ^ o ^PROCESS. Because of its reactivity, SO 2 drift is often considered the most non-reactive pozzolanic additive. As stated by P. Jahren in Use of sslica fume in concrete / Am. Concr. Inst. Spec. PpbLic. 79-32, 627-642, 1982 /, drift Si02 addition to concrete improves zpracooa l.nos ^ ^{y with} _a Vol šuje its ^C <^ ^h strength and allows to reduce the crowd ^to the cement in concrete.

THE

Ppoužii drift Si02 is known from the patent documents e.g. Burg Hi ^gh ftreng-CEM ^ e ^ IT Co ^ ^m or ^Sj Es ^from - Swiss ⁵⁷⁴ 88 (0 Austria 312 490/19711 which describes a concrete mix of portaandsкého cerium ^ NNU sand and stone, which further contains up to 20% of the drift, SSO2, and the addition of a skid coat. it has a finite particle size distribution of up to 0.5 microns and the remaining particles of 5 nanometers to 0.5 microns are formed by SiO2 drift into the concrete with the addition of plasmidizers. reeiaatdz suloonované AAF ^t Alea ^d and hoiHH Lulea ^ is ^- again ^- Zn ^and Mo ZCL, ^{1-0214137 / S. S} laai ^RC and ^a Be-NSV ^ o ^ u ^to orozn ^d of ^d r ^j nart ^t / ^Ac de is woven or roughly streamed. Men, o ^ J ^ C ^ ahujcí 3 1 * 20% HMO. Amorn ^ he S ^, composed of at least 30% čássic Mees than 3 mkromery and at least 50)% čássic mmaššch than 2P me ^ lim ^ u ^{0, 5} * ¹ % wt. with the advantage of a water-soluble, water-soluble resin or non-calcium or condensation product tyseeiad aaftaleasub.ko253 49S

The novel form of Idehyd, and from 0.001 to 3% by weight of the additives, preferably aerated the additives with lauryl sulphate or sodium abietate.

All known solutions of cements or concretes with the addition of highly fine amorphous SiO 2 are based on Portland or slag-portland cement, which contains gypsum as a solidification regulator. When using high-grade amorphous S10j, the workability of the mix (concrete) was improved by filling the gaps with cementitious particles with a much finer SiO 2, but to achieve good workability at low water coefficient / water / cement ratio / W <0.35 sheathing agents (e.g. Switzerland 574 880, or Europ. Appl. 81 105 310.7, which discloses plasticizer doses of 3 to 7.2 wt. cement. This amount is considerably higher than in conventional concrete coaters. However, a reduction in this high dose of the coating is possible only at the cost of increasing the water coefficient, as shown in CsO 214 214, where only 0.3% to 0.5% by weight, of the jacket or additive (based on the weight of the cement) was used. increase of water coefficient of concrete mixture up to w ^with 0.78.

It is further known from en <200 200 215 cement clinker binder with a specific surface area of 150 ^ 3000 m ^ / kg, in which 2 ^ 95% by weight. % of the particles having a particle size of not more than 5 micrometers, containing 0.01 to 8% by weight of lignin sulphonate-based substances, mixing water and 0.01 * 8% by weight, respectively. carbonate or acid carbonate

V. an alkali metal or alkaline earth metal, and / or 0.1-8 wt. other known binder additives, calculated on the total amount of clinker, and containing 5% to 90% by weight of a substance containing an oxygenated silicon compound such as bentonite, silica meal, ash, slag and a mixture of two or more such substances, calculated on total amount of clinker.

These disadvantages are overcome by the invention which is based on a gypsum-free cement clinker binder containing 99.5-88% by weight, ground cement clinker having a specific surface area of 225-800 m @ 2 / kg and 0.001 <2% by weight. % of known grinding agents, e.g. triethanolamine, ethylene glycol, 0.2 in 4 wt.

% 5 253 499 alkali metal salts or hydroxides, e.g. Na ₂ CO ₃ , NaHCO ₃ , _{2 2 3 3} ^ζ ₃ CO KHCO 3, NagSiO 3, 0.2 3 3 wt. sulfonated polyeltrolytes, e.g., ligninsulfonate, chemically treated ligninsulfonate _from sulfonated lignin, sulfonated polyphenolate, and optionally 0.1% by weight of known gypsum cement solidification regulators, e.g. 0.05 to 20 wt. SiOg _} preferably amorphous SiOg from the production of Si or FeSi having a specific surface area of 5000-4,200,000 m m / kg, containing more than 50% of particles smaller than 5 microns, the percentages by weight being based on the weight of the clinker.

According to the invention, it has been found that when using a synergistic mixture of a sulfonated polyelectrolyte / e.g. ligninsylphonate, sulfonated polyphenolate, etc., and an inorganic electrolyte (e.g. carbonate / it is possible to process a mixture of BS cement and SiO ₂ drift at a water coefficient W <0.30, while maintaining good rheological properties with a significantly lower coating agent than with Portland cement.

When studying the effect of oxygen-containing silicon compounds on cement clinker-based binder properties, it was found that the particle size and physical state of these compounds, in particular SiO ₂ , have a considerable influence on the properties achieved. In order to improve the rheological properties of the binder, it is very important to fill the space between the cement particles with parts such as high-fine SiO _2. This means that the mean particle size of such a binder must be smaller than the smallest cement particles. When overlapping the granulometric curve of the cement and the active ingredient (e.g. SiO ₂ in the form of quartz flour, SiO ₂ in the form of leaches, or so-called pike from kaolite treatment plants / there is a significant deterioration of rheological properties and it is not possible to achieve good workability at low water coefficient. On the other hand, the use of the S10 ₂ according to the invention in a highly fine form, wherein the mean particle size detected by e.g. a scanning electron microscope is about 0.1 micrometer and less / e.g. SiO ₂ drift from metallurgical processes or pyrogenic S10 ₂ /, complements the granplometric curve of the cement and allows the preparation of a highly compact powder. This powder then requires only a minimum of water during processing

253 499 provided that the cement powder does not contain gypsum.

The physical state of SiO ₂ is also very important. For the reactivity of SiO ₂ with Ca / OH / ₂ , which results in pH hydration of the cement, the amorphous state of SiO ₂ is optimal. · By increasing the crystalline fraction in S10 ₂ , it was finely ground, its reactivity is reduced. According to the invention, it is optimal to use SiO ₂ with a high specific surface area, a very small mean particle size, preferably in an amorphous state.

The use of highly fine amorphous SiO ₂ with optimum concentration as an additive to BS cements not only improves their rheological properties, but also allows to overcome the above instability / fluctuation of solidification on BS cements with a specific surface area of less than 450,500 µL / kg. The addition of a high fine amorphous S10 ₂ to BS cement enables rapid development of the strength of the rapid development of the nucleus CSH phases. An increase in the strength of BS cements is manifested at a lower SiO ₂ drift concentration than is known in the art. This increase, especially of short-term strength, is apparent from the limit of about 0.1% by weight. addition of SiO ₂ drift (based on cement weight) and in some cases at a lower concentration.

In the following examples, the present invention is presented without limiting it.

In assessing the rheological properties of the slurry was used

Emp 'empirical scale of visual assessment:

workability

0 ... unprocessed porridge, dry

1 ... the slurry flows only at 50 Hz vibration

2 ... the porridge flows only when you tap the mixing bowl

3 ... the slurry flows out of the mixing bowl due to gravity

4 ... the slurry is free flowing

5 ... the slurry is free flowing with low viscosity

When preparing the test specimens, the prepared specimens were stored in saturated water vapor for 24 hours and then in water at 20 ° C until day 28.

The percentages in the examples are always based on the weight of the ground cementitious cement (unless otherwise stated).

EXAMPLE 1

253 499

Cemented pre-crushed cement The boundary should be cleaned to a specific surface of 300 m / kg with the addition of 0 _x 05% by weight of trieannotamine. Immediately after cement. 200 grams of cemeen was weighed into ground joints. Ground-glass bottles apartments parafíeem you cast so that the ^y goodbyes BC, ^dh ydratacn cement crow humid ^to Ostia. A slurry of 0.4% by weight was prepared from the monolithic ground joints at the given time intervals. % of sulfonated sodium polyphenate and 1% wt. NagCO ^. In the porridge be observed the beginning of ^ ЬпиМ. ^P ro ^d ý after ^the US ^b YLA load applied from only one ^e zálsrusové bottles and others were further stored. At the same time intervals, slurries were prepared from the same cement under the same storage conditions, when SiO2 drift was added to the cement at a quantity of Ц1 wt%, and the onset of slurry solidification with the same additives was also monitored. The results of the determination of the onset of solidification are given in Table 1.

The SiO 2 used in these experiments and hereafter referred to as the drift is a product of crystalline Si production. Its composition is SiO2 min. 95%, ^ 2 ° max max 0.5%, A-20 max max 0.4%, CaO max 0.4%, MgO max 0.4%, C max * 0.6%, H ₂ O 'max. 0.5% (relative to the SO ₂ ). The SiO2 marketed under the commercial name KOMSIL is virtually ammonium based on RT6 analysis. It has been determined by scanning and electron microscopy that the particulate debris contains clusters of particles predominantly 2 to 6 microns, while single particles have a mean size of 0.2 microns.

Table 1

Start _of solidification _of water slurry: cement 0/22 «

253 499 days of storage SiO2 drift content

42

102

1 5hod30mi n 2 5hod20mi n 7 1hod20mi n 10 3hod15mi n 15 Dec 3h 20 May over 7hod 25 3hod30mi n 30 6hod30mi n 31 up to 180 days fluctuates between 7 * 18 hrs

2h30min storage start,

1hr40min 1hr25min

52mi solidification stable throughout the entire dispersion of results + 52 times

Example 2

After 14 days of storage in a ground-glass bottle, a slurry was prepared from the cement prepared according to Example 1 to make 2x2x2 cm test specimens. As in Example 1, 0/42 wt. sulfonated sodium ironphenol polyphenolate and 12 wt% ^and 2 ^CO 3 ^and SiO ₂ drift also added. The results are shown in Tab. 2.

Table 2

253 499

water cement water cement + ^s i ° ₂ drift content sieve ₂ processing 0.22 0.219 1% 3 0.22 0.217 2% 3-4 0.22 0.211 4% 3-4 0.22 0.207 6% 4-5 0.22 0.205 8% 4 0.22 0.200 10% 3-4 0.22 0.192 15% 3 0.22 - 0% 2-3

Compressive strength / МРа /

2 hrs 24 hours 7 days 28 days 10.8 62.5 71.3 79.8 0, 8 65.8 95.3 105.8 12.8 65 _of 5 90.5 97.0 10.5 58.3 87.8 107.0 13,4 ^X 60.0 89.0 102.0 13.0 64.8 88.0 102.3 12.4 60.2 - - 4.0 60.5 90.1 100.7

^x pozn. Strength determined after 3 hours

Example 3

From the clinker from the Lochkov cement plant, cement was admixed with 0.05% by weight of triethanolamine in the absence of gypsum to a specific surface area of 470 m / kg. The cement storage conditions were the same as in Example 1. Of this cement, 0.4% by weight, sulfonated sodium ferric polyphenolate and 1% by weight were added. Water-to-cement slurries of 0.22 were prepared for Na 2 CO 3. As in Example 1, a SiO ₂ flux was also added in an amount of 2 to 10% by weight. The results of the solidification determination are shown in Table 3.

Table 3 253 499 days of glass SiO2 drift content dovaní 0% 2% 8% 10% 1 1hr50min 1hr50min 1hr23min 1hr 55mi n 45min 2 1hr40min 3 2hod30mi n solidification start stable after throughout 4 2h storage with dispersion + 5% 6 35min

1hr20min

90min

3hr50min

2h15min

2h

2h10min

3h30min

4hod30min

100 3hod50min

Example 4

Under the same conditions, a cement slurry was prepared according to Example 3 from the Lochkov cement plant. The difference from Example 3 was in the additives where 1.2 wt% ^Mg > 2 ° ^C and 0.85 wt% oxidized sodium lignin sulphonate were used. When using a 2 wt% SiO 2 additive, the onset of solidification was 55 minutes, with the addition of 6 wt%.

minutes at 8 wt. 45 minutes and 10% by weight · 40 minutes. The onset of solidification was stable for the monitored storage period in the absence of atmospheric humidity for 3 months.

Example 5

A slurry was prepared from the cement prepared according to Example 3 after 14 days of storage under the conditions of Example 3. The results are shown in Table 4.

Table 4

253 499

water water content zpra cova- strength in pressure / MPa / cement cement drift teltust 2h 2čhod 7 days 28 days + Si й2 sio ₂ 0.22 0.217 2% 3 10.0 59.8 72.8 101.5 0.22 0,2 11 4% 4 21.8 55.8 61.0 105.9 0.22 0.205 8% 4 «5 16.0 68.7 60.8 106.7 0.22 0.200 10% 4eí5 18.7 51, 2 76.4 93.7 0.22 - 0% 3 5.0 52.0 75.6 100.2

Comparative experiment

Made of Portland cement PC

2 ........ _

400 · Lochkov with a specific surface area of 380 m‘ / kg was flooded with the addition of 6% by weight. The slurry water coefficient should be selected so that the slurry processability reaches a degree of 3 «4 according to the selected empirical scale. The value of the aqueous salt of the reader was w - 0.40. The PC 400 slurry with the addition of 6 wt.% SiO 2 drift reached virtually unstable 2 hours after hardening, after 24 hours the bag strength was 34.8 MPa and after 7 days 50.3 MPa. Comparison of Example 1 <A5 shows that by eliminating gypsum and replacing it with a combination of shredder and inorganic salt in cement, SiO? to achieve substantially higher effects.

For the preparation of the cement slurry a ground clinker from the Maaomerice Cement Plant was used, which was ground with 0.1% hmoo ingredients. of ethylene glycol to a specific surface of 720 m ² / kg. 1.1% wt. % of oxidized li-g / neu sodium and 1% hmmt. NaHCO3. The ground clinker was mixed with very fine SiO 2 (pellets and kadine treatment plants) in the first case and in the second case with the SSO ₂ drift before slurry preparation. S02 in the form of pike was predominantly crystalline in character (according to X-ray daa), while SS02 drift was practically.

253 499

Bone particles:. sedimentation analysis - below 2 microns 25%, 5 <g 2 microns 17.3%, 10 and 5 microns 22.5%, 15 10 microns 15.5%, 20 ® 15 microns 8.29%, 63 £ 20 micrometers 11%.

The results of the rheological properties of the slurry are shown in Table 5.

Table

Ingredients processability water by empirical cement degree ce 80%. cement + 20% pike SiOg «0« 1 0.30 90% cement + 10% went SiOg . 1rf2 0.30 95% cement + 5% Si0 ₂ 2 0.30 100% cement 5 0.30 85% cement + 15% drift S10 ₂ 3 0.22 90% cement + 10% drift SS0 ₂ 3 «4 0.22 94% cement 6% SiO ₂ drift 4 0.22 96% cement 4% SiO ₂ drift 4ri5 0.22 98% cement 2% drift H0 ₂ 3eí4 0.22 100% 'cement 2 0.22

The boundaries of the clinker has been produced with circular mýnici bezsádrovcový u ^ cement clinker Etim nepřitomnoosi gypsum to specific ^p ovrc ^{h 710} m ^{2 / kg.} MleM communication was prov ^ADE well as jplMsadty if gnnnsuui onan sodnnAo and 0.8% by weight. NagCO ^. was partially modified succulent leachate, which mmonosachaidy and its oxidation products, substances in lignosulfonate were characterized by pilot plant

1% by weight of powdered sodium ligninsuioonate contained an accompanying accompanying organic analysis of reducing substances whose concentration was 6.7% (calculated on the dry matter content of ligninsuioorane). Of this BS cement was. prepared a slurry with a water to cement ratio w = 0/25, which. had a workability according to an empirical scale of 2 rl 3

253 499 of this porridge apartment 4.5 to 6 hours. Next, a slurry of the same cement was prepared to which 6% w / w was added. SiO ₂ drift. This slurry had a water to cement ratio also w = 0.25, the water to total solids ratio (cement + SiC drift) was 0.238. This slurry had an onset of solidification after 1 hour and 10 minutes (which practically coincided with the solidification time). Further, the cement slurry was also prepared at a water to cement ratio of 0.238, and the slurry processability was improved by adding SiO drift to the BS cement at the wall water content (and increasing the total solid phase content). The addition of SiO2 drift also overcame the negative effects of lignosuccinate with a high content of accompanying organic substances and thereby stabilized the properties of this cement.

Example 8

A slurry having a water to cement ratio ws of 0.25 was prepared from the clinker clinker from the Lochkov cement plant ground to a specific surface of 550 m / kg (at a grinding additive of 0.2% by weight, sodium lignin). 0.5% by weight was used as an additive. sodium potassium tartrate and 1.5 wt% KgCO 3. In addition, 4 wt% SiO ₂ drift was added. This slurry had a solidification onset of 45.

Example 9 '

To the cemeritarian sun from a cement plant boundary ground to a specific surface of 590 m / kg with the addition of 0.1% by weight, ethylene glycol was dry added 4% by weight. Si0, / product fimy Baye FRG Murni surface ^£ 152,000 meters / kg /. The slurry was treated at a water to cement ratio w = 0.24 and had an eroppic workability of 3 <

Example 10

A matte with a sand to cement ratio of 1: 3 was pumped from the Lochkov cement plant shade ground to a specific surface of 450 m ² / kg. The following ingredients were used: 5% hmoo. Si ^ drift,

253 499

0.4 wt. % of sulfonated sodium gelatin polyphenolate and 1 wt.

water to cement

w = 0/30, the ratio of water to total solid phase (cement + SiO 2 drift) was 0.283. The mortar reached 6 MPa after 6 hours and 40 MPa after 24 hours. The mortar setting time was 1 hour.

Example 11

A slurry with a water to cement ratio of 0.22 was prepared from the clinker from the Lochkov cement plant _from which it was ground to a specific surface of 590 m ² / kg and 0.1% ethylene glycol additives. Prior to slurry preparation, a 0.2% SiO ₂ drift was added to the cement. Other additives, i.e. 0.4 wt. % sulfonated sodium ferric polyphenolate and 1 wt. At ₂ CO ₃ they were dissolved in the mixing water. The slurry had a setting time of 25 minutes and reached a compressive strength of 14.8 MPa 2 hours after solidification. The slurry treated with the same water to cement ratio and with the same additives (without SiO ₂ drift) reached a compressive strength after 2 hours after solidification of ^7.2 MPa.

Claims (1)

A binder with stabilized properties based on gypsum-free cement clinker) containing 99.5% by weight 88% by weight. ground clinker having a specific surface area of 225 to 800 m / kg or 0.001% by weight; % of grinding agents, e.g. triethanolamine, ethylene glycol, 0.2 x 4 wt. % of an alkali metal salt or hydroxide, e.g. Na ₂ CO 3, NaHCO 3, K ₂ CO 4, KHCO 3, Na ₂ SiO ₂ , 0.2 to 3 wt. % of a sulfonated polyelectrolyte, e.g., lignin sulfonate, chemically modified lignin sulfonate, sulfonated lignin, sulfonated polyphenolate, and optionally 0.1 to 3 wt. solidification regulators of gypsum-free cement, eg salts of organic hydroxides, boric acid, organosilicon esters, phosphates, characterized in that it contains 0.05% by weight 20% of silicon dioxide, preferably a? f surface area 5000 Q from 200 000 m ² / kg, containing more than 50% of particles smaller than 5 microns, the percentages by weight being based on the weight of the clinker.