CN103743605A - Carbomer gel medium for simulating rheological property of cement paste and preparation method thereof - Google Patents

Abstract

The invention provides a carbomer gel medium for simulating rheological property of cement paste and a preparation method thereof. The carbomer gel medium for simulating rheological property of cement paste comprises the following components by weight percent: 99.70-99.75 percent of deionized water, 0.15-0.18 percent of carbomer resin powder and 0.10-0.12 percent of triethanolamine (serving as a neutral regulator), wherein the water cement ratio in the carbomer gel medium for simulating rheological property of cement paste is 0.45-0.5. The preparation method comprises the following steps: adding the carbomer resin powder into the deionized water, dripping the triethanolamine after the powder is completely dissolved, uniformly stirring, standing for 5-10 minutes so as to obtain transparent carbomer gel. The 940 series of carbomer gel serves as a simulation medium of the cement paste, and the carbomer gel medium is low in cost, simple to prepare, high in transparency, low in thixotropy, small in time-dependent behavior of rheological parameters and obvious in pseudoplastic characteristics.

Description

Carbomer gel medium of simulation cement paste rheological property and preparation method thereof

Technical field

The invention belongs to material technology field, be specifically related to carbomer gel medium of simulating cement paste rheological property and preparation method thereof.

Background technology

Concrete mix component is very complicated, and its rheology mechanism it be not immediately clear, does not also form more perfect mechanics parameter system, and reason is the comparatively difficulty of physical experiments that rheology concrete is accurate.Because cement slurry inside cannot be visual, cause the internal composition characteristics of motion to be difficult to obtain.Tradition research method is difficult to intuitively obtain media components kinematic parameter and sets up reliable physical model.Therefore, adopt visual transparent medium place of cement slurry, can more easily obtain the particularly motion morphology parameter of granule medium of slurry component, for physical experiments and checking provide possibility.

Summary of the invention

The object of this invention is to provide Simulated Water gray scale and be carbomer gel medium of 0.45～0.5 cement paste rheological property and preparation method thereof.

The carbomer gel medium of simulation cement paste rheological property, comprises: deionized water 99.70～99.75%, carbomer toner 0.15～0.18%, neutral correctives triethanolamine 0.10～0.12% by weight percentage; The cement paste rheological property that above-described carbomer gel medium Simulated Water gray scale is 0.45～0.5.。

In the carbomer gel medium of above-mentioned simulation cement paste rheological property, described carbomer toner is 940 serial carbomer resins.

The preparation method of the carbomer gel medium of above-mentioned simulation cement paste rheological property, comprise the following steps: carbomer toner is added in deionized water, drip until completely dissolved triethanolamine, standing 5～10min after stirring, obtains transparent carbomer gel.

Slurry flowing performance-changing is the basis of sand-cement slurry and concrete mix rheological property, its rheological curve is power exponent distribution, meets power-law fluid model (Jacek Gol Caszewski, Cement and Concrete Research, 2004,34:235-248).The rheological characteristics of this fluid model shows as apparent viscosity and changes with the increase of shear rate, and cement slurry is generally pseudoplastic fluid, and its apparent viscosity reduces with the increase of shear rate.

Carbomer claims again carboxyl ethylene copolymer, is the conventional high polymer adjuvant of preparing the semisolid preparations such as gel, under very low concentration, can form the high-viscosity gel with bioadhesive.Wherein, 940 serial carbomer resins are multipolymers of acrylic acid and allyl pentaerythrite or allyl sucrose cross-linked polymer, can be used as suspending agent, stabilizing agent, emulsifying agent and water-soluble thickener, than thering is more good endurance of cutting, possess that cost is low, transparency high with other serial carbomer resin-phases such as 934 and 941 simultaneously.Carbomer gel has pseudoplastic characteristic of fluid and rheological property stable (GiuliaBonnacucina, Journal of Pharmaceutics, 2004,282 (115): 130).

The present invention adopts the simulation medium of 940 serial carbomer gels as cement paste, with low cost, preparation is simple, transparency is good, thixotropy is little, rheological parameter rheological parameters' change with time is little and pseudoplasticity feature is obvious.

Accompanying drawing explanation

Fig. 1 be carbomer concentration to gel rheology energy influence curve, wherein 1 is the rheological curve of 0.15% concentration carbomer, 2 is the rheological curve of 0.2% concentration carbomer, 3 be 0.3% concentration carbomer rheological curve;

Fig. 2 is cement paste and the contrast of carbomer gel rheological curve, wherein 1 rheological curve for the water cement ratio cement paste that is 0.5,2 is the rheological curve of 0.13% concentration carbomer, and 3 is the rheological curve of 0.15% concentration carbomer, and 4 is the rheological curve of 0.17% concentration carbomer.

Embodiment

Adopt rotary viscometer to investigate the rheological property of carbomer gel, with the increase of carbomer concentration in system, the viscosity of corresponding gel also constantly increases.The rheological curve that Fig. 1 is 0.15%, 0.2%, the carbomer gel of 0.3% 3 kind of concentration changes with different shear rate at neutrallty condition down cut stress, as seen from the figure, the carbomer gel rheological curve of three kinds of concentration all shows as shear stress and is power exponent rising tendency with shear rate, meets power-law fluid model.

Embodiment 1

The carbomer gel medium of the cement paste rheological property that Simulated Water gray scale is 0.5, cement is P.O42.5, is comprised of the component of following percent by weight: deionized water 99.75%, carbomer toner 0.15%, triethanolamine 0.1%.

Carbomer toner is added in deionized water, drip until completely dissolved triethanolamine, after stirring, obtain clear gel.

1. degree of fitting check

Choose residual sum of square method of inspection, this method of inspection can highlight difference between parameter value in the situation that curvilinear trend is similar, is convenient to improve degree of accuracy, finds out the curve that fitting degree is the highest.According to regretional analysis principle, curvilinear regression effect quality index of correlation R ²weigh.Index of correlation R ²computing formula is:

In formula: S _rrepresent regression sum of square; S _trepresent square sum of total departure; S _surplusrepresent residual sum of squares (RSS); y _irepresent model value; F (x) represents former offset.

In the similar matching of cement paste, the cement paste water cement ratio of former shaped material is 0.5, cement selection P.O42.5 cement.By test, find, select carbomer gel strength scope between 0.13%～0.17%, the grout of rheological curve and water cement ratio 0.5 is very approaching, and rheological curve as shown in Figure 2.

Contrasting two rheological parameter denseness is K and rheological behavior index n, the carbomer gel regression curve equation of concentration 0.15% and cement paste degree of fitting R ²be 0.96, far above the carbomer gel of other two kinds of concentration, show accurately to simulate prototype material flowing deformation parameter by adjusting carbomer concentration.

2. identity property check

The checking of simulation medium material identity property, supposes that starting material have been set up the statistics reference value of the correlativity being obtained by mass data and experience and through confirming, cement slurry meets this supposition as starting material.Therefore the check of identity property method applied statistics is verified simulation medium.Statistical Identifying Method needs test simulation MEDIA FLOW variable element that its mean value is dropped in a tolerance interval, does not have too high expectations or too low mean value.If totally Normal Distribution all of the sample of all rheological parameters, checking simulation medium adopts sided t to check with the Statistical Identifying Method of prototype material flowing deformation performance identity property.Under identical test condition, comparative test result difference.Above-mentioned two media statistical check analysis is as follows:

With X and Y, represent the data sample of prototype and cast material, n ₁and n ₂represent the data amount check of prototype and model sample, S ₁and S ₂represent the standard deviation of prototype and model sample data.If X and Y Normal Distribution and population variance the unknown are unequal, min{n ₁, n ₂<30, the small sample sided t method of inspection can be selected.When bi-material test figure sample is during without significant difference, statistical test amount t ₀be expressed as:

$t_0=\frac{\stackrel{\&OverBar;}{X}-\stackrel{\&OverBar;}{Y}}{\sqrt{\frac{{S_1}^2}{n_1}+\frac{{{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="131217141046.png"\; state="\{\{state\}\}">S</figure-callout>}}_2}^2}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="131217141046.png"\; state="\{\{state\}\}">n</figure-callout>}}_2}}}~t\left(v\right)$

Wherein ν represents the degree of freedom that t distributes, by ν=min{n ₁, n ₂}-1 is chosen.

The carbomer gel degree of fitting assay that is 0.15% according to the cement paste that is 0.5 to water cement ratio and concentration, bi-material rheological parameter is approximate, rheological curve is similar.Test data meets small sample sided t examination requirements, therefore can further analyze judgement by the check of material identity property.

The former shaped material of table 1 and the contrast of simulation medium rheological parameter statistic

Take consistency index K as example, according to sided t check formula, can obtain:

${\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="131217141046.png"\; state="\{\{state\}\}">t</figure-callout>}}_0=\frac{\stackrel{\&OverBar;}{X}-\stackrel{\&OverBar;}{Y}}{\sqrt{\frac{{S_1}^2}{n_1}+\frac{{{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="131217141046.png"\; state="\{\{state\}\}">S</figure-callout>}}_2}^2}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="131217141046.png"\; state="\{\{state\}\}">n</figure-callout>}}_2}}}=\frac{7.487-7.677}{\sqrt{\frac{{0.5566}^2}{10}}+\frac{{0.3771}^2}{10}}=-0.894$

Under the condition of level of significance α=0.05, for sided t check, known t _α/2(ν)=t _0.025(10-1)=2.2622.And 0.894 in ± 2.2622 scopes, illustrate that the test figure of bi-material is without significant difference, consistency index K identity property check is confirmed, and the consistency index of the carbomer gel that concentration is 0.15% meets the rheological parameter simulation requirement that water cement ratio is 0.5 cement paste.

In like manner, the cement paste that can be 0.5 to water cement ratio and concentration are that the rheological behavior index of 0.15% carbomer gel carries out the check of small sample sided t, and assay is as shown in table 2.

Table 2 carbomer gel statistic assay

Result shows: under the condition of level of significance α=0.05, carbomer gel consistency index and rheological behavior index as cement paste simulation medium all obtain good material identity property check, therefore adopt parameter simulation method, it is feasible selecting the accurate Simulated Water slurry body of carbomer gel.

Every statistic such as table 1 contrasts and shows, carbomer is prepared the dispersion degree characterization values such as the standard deviation of gelled specimen data and is all less than starting material, illustrates that simulation medium is more favourable for simulation starting material Instantaneous State rheological property.In addition, the high grade of transparency of simulation medium is enough to meet in the medium of simulation concrete mixture the aggregate visual testing requirements of moving.

Test shows, the thixotropy of simulation medium is much smaller than prototype slurry, during its shear rate first increases and then decreases, the ascent stage of rheological curve and descending branch curve overlap substantially, the rheological property contrast (table 3) constantly changing with shearing with cement paste can draw, better in a certain instantaneous rheological property accuracy and data stability with the carbomer gel simulation starting material of high endurance of cutting.

Table 3 carbomer gel and cement paste rheological curve ascent stage and the contrast of descending branch rheological parameter

Embodiment 2

The carbomer gel medium of the cement paste rheological property that Simulated Water gray scale is 0.48, cement is P.O42.5, is comprised of the component of following percent by weight: deionized water 99.73%, carbomer toner 0.16%, neutral correctives triethanolamine 0.11%.

Carbomer toner is added in deionized water, drip until completely dissolved triethanolamine, after stirring, obtain clear gel.

Contrasting two rheological parameter denseness is K and rheological behavior index n, and the carbomer gel regression curve equation of concentration 0.16% and water cement ratio are 0.48, cement is P.O42.5 cement paste degree of fitting R ²be 0.98.

Under the condition of level of significance α=0.05, as carbomer gel consistency index and the rheological behavior index of the cement paste simulation medium of water cement ratio 0.48, obtain good material identity property check.

Embodiment 3

The carbomer gel medium of the cement paste rheological property that Simulated Water gray scale is 0.45, cement is P.O42.5, is comprised of the component of following percent by weight: ionized water 99.70%, carbomer toner 0.18%, neutral correctives triethanolamine 0.12%.

Carbomer toner is added in deionized water, drip until completely dissolved triethanolamine, after stirring, obtain clear gel.

Contrasting two rheological parameter denseness is K and rheological behavior index n, and the carbomer gel regression curve equation of concentration 0.18% and water cement ratio are 0.45, cement is P.O42.5 cement paste degree of fitting R ²be 0.97.

Under the condition of level of significance α=0.05, as carbomer gel consistency index and the rheological behavior index of the cement paste simulation medium of water cement ratio 0.45, all obtain good material identity property check.

Claims (3)

1. the carbomer gel medium of simulation cement paste rheological property, is characterized in that, comprises by weight percentage: deionized water 99.70～99.75%, carbomer toner 0.15～0.18%, neutral correctives triethanolamine 0.10～0.12%; The cement paste rheological property that above-described carbomer gel medium Simulated Water gray scale is 0.45～0.5.

2. the carbomer gel medium of simulation cement paste rheological property according to claim 1, is characterized in that: described carbomer toner is 940 serial carbomer resins.

3. the preparation method of the carbomer gel medium of the simulation cement paste rheological property described in a claim 1 or 2, it is characterized in that: comprise the following steps: carbomer toner is added in deionized water, drip until completely dissolved triethanolamine, standing 5～10min after stirring, obtains transparent carbomer gel.

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