CN102230873B - Method for determining actual maximum expansion rate of foamed asphalt - Google Patents

Abstract

The invention discloses a method for determining the actual maximum expansion rate of foamed asphalt. The method comprises the following steps of: 1) acquiring measured value ERm, half-life period tau 1/2 and injection time ts of the maximum expansion rate of the foamed asphalt under any foaming conditions; and 2) determining the actual maximum expansion rate ERa of the foamed asphalt according to the formula in the specification. The method has the advantages of convenience of calculation and accurate results. The ERa can be acquired according to the ERm, the tau 1/2 and the ts which are measured under any foaming conditions.

Description

The method of the actual maximum swelling rate of a kind of definite foamed asphalt

Technical field

The invention belongs to the road engineering field, relate in particular to definite method of the actual maximum swelling rate of foamed asphalt.

Background technology

The foam characteristics of pitch is one of key factor that influences foamed asphalt mixture performance and cold reengineer application success or failure.

At present, expansivity (ER is mainly adopted in the foam characteristics evaluation of pitch _m) and half life period (τ _1/2) index.Expansivity is meant the ratio of the volume under the maximum volume of measuring under the asphalt foaming state and foamed state not; Be actually a kind of measurement mode of pitch viscosity; The viscosity of the big more explanation pitch of expansivity is more little, and the area that contacts with compound is big more, mixes and stirs more easily.Half life period has then been described the stability of foamed asphalt, and the half life period is long more, explains that foamed asphalt is not easy decay more, and is long more with the time of mixing and stirring of gathering materials.

1999, the Jenkins professor of South Africa Stellenbosch university pointed out that in the process of air blown asphalt, foamed asphalt has just declined, and causes the maximum swelling rate ER that measures like this before measurement volumes when research asphalt foaming process _mBe not equal to actual expansivity ER _aThe asphalt foaming time-continuing process is long more, and the foamed asphalt half life period is short more, ER _mWith ER _aDifference big more, adopt ER _mWith the best foaming of appreciable impact pitch Determination of Parameters.

Jenkins provides ER _aExample as shown in Figure 1, frothing test injecting time t _sBe 5s,, carry out iteration then successively times 10 five equilibrium of foaming process.When being t=0s, volume V ₀=0; During t=0.5s, volume V _0.5=V ₁₁During t=1s, by V ₁₁Calculate V ₂₁, volume V ₁=V ₂₂+ V ₂₁Iteration is last successively must V ₅=V _Max, promptly the frothing test foamed asphalt sprays the measured foamed asphalt volume finish time.

Though the method for Jenkins can be obtained ER _aBut, the computation process more complicated.For this reason, Jenkins has provided the ER under the partial foaming condition _mAnd ER _aValue (table 1), defined c=ER _m/ ER _a, and the ER under the partial foaming condition _aAnd ER _mThe nomogram (Fig. 2) of relation.

But the method for Jenkins can only be to the ER under the specified conditions _m, τ _1/2And t _sAsk ER _a, have bigger limitation.Work as ER _m, τ _1/2And t _sNumerical value can only be asked ER through the method for looking into Fig. 1 not in table 1 _a, have certain error.Work as τ _1/2When numerical value was not Fig. 2 horizontal ordinate mark numerical value, error had the trend of increase.Work as t _sWhen numerical value was not given 1,2,5 or the 10s of Fig. 2, this method can't be tried to achieve ER especially _a

Table 1ER _mWith ER _aRelation

To sum up, use the expansivity ER that directly records in the prior art _mAs ER _a, the result is very inaccurate; And the ER of Jenkins _aCalculation of complex under the efficient, also exists out of true as a result, the defective of restricted application simultaneously.

In addition, testing laboratory's test asphalt foaming characteristic is mainly through changing foaming parameter (blowing temperature, water consumption) research expansivity and the Changing Pattern of half life period, in the hope of finding best foaming effect.Generally, expansivity and half life period are a pair of conflicting evaluation indexes, choose bigger expansivity or long half life period separately, all can not reach satisfied effect.All be fit to the numerical value of practical applications in order to obtain both, need to seek both equilibrium points, promptly expansivity and half life period all are in the allowed band of practical applications.Yet the foaming parameter that satisfies the practical applications requirement often is not unique, owing to there is not clear and definite numerical Evaluation standard, is difficult to judge best foaming parameter in some cases.

Asphalt foaming test fundamental purpose is the best blowing temperature and best foaming water consumption that is used for confirming pitch.China's asphalt pavement regeneration standard to the technical requirement of foamed asphalt is: expansivity >=10, half life period >=8 second.In the regeneration standard, as shown in Figure 1, according to the water consumption m that confirms to allow that expansivity is corresponding ₁With the water consumption m that allows that the half life period is corresponding ₂, average as best foaming water consumption m _Opt, m _Opt=(m ₁+ m ₂)/2.This is actually a kind of state of more satisfactoryization, and gained foaming data should satisfy the increase along with water consumption, expansivity monotone increasing, this situation of half life period monotone decreasing.Actual frothing test data maybe be so not desirable.Main phenomenon has:

(1) half life period might not increase and dull the minimizing with water consumption, particularly when water consumption is big.

(2) if all greater than the standard allowable value, having only to delay just through regression curve so, test findings can obtain m outward ₁And m ₂Value, the possibility of result of the best water consumption of gained this moment can exist than large deviation.

When above-mentioned situation occurred, this foaming parameter determination method just lacked operability.And even if test figure is more satisfactory, in the time of can calculating according to the method, the gained water consumption also is not necessarily best.This be because, the method obviously lacks mathematics and physics basis, and is different when allowing desired value when getting for one group of given asphalt foaming test figure, the best of gained water consumption that foams is different, this obviously is not inconsistent convention.Therefore, confirm that at present the asphalt foaming parameter still is judged as the master with experience, general way is to draw expansivity, half life period with the curve map that water consumption changes according to the frothing test result, gets all bigger situation of expansivity and half life period.

Summary of the invention

In order to address the above problem; The object of the present invention is to provide the method for the actual maximum swelling rate of a kind of definite foamed asphalt; Have convenience of calculation, the accurate advantage of result; Thereby can be efficiently, confirm the foam characteristics of pitch rationally, accurately, for the selection of engineering medium pitch provides reliable foundation, preventing influences construction quality because of the error in judgement of asphalt foaming characteristic.Another object of the present invention is the method that has proposed a kind of foaming capacity of definite foamed asphalt, and this method is estimated according to actual maximum swelling rate of the present invention.

To achieve these goals, the method for the actual maximum swelling rate of definite foamed asphalt provided by the present invention comprises:

1) carries out the foamed asphalt frothing test under the foaming condition arbitrarily, obtaining the measured value ER of the maximum swelling rate of foamed asphalt _m, half life period τ _1/2With injecting time t _s

2) according to following formula

${\mathrm{ER}}_a={\mathrm{ER}}_m\&CenterDot;\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s/[1-\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s)]---\left(2\right)$

Confirm the actual maximum swelling rate ER of foamed asphalt _a

The method of the actual maximum swelling rate of definite foamed asphalt of the present invention obtains through following manner:

The foamed asphalt decay equation of selecting Jenkins to propose:

$\mathrm{ER}\left(t\right)={\mathrm{ER}}_m\&CenterDot;\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t)---\left(1\right)$

Referring to Fig. 3, asphalt foaming is a process of spraying while foaming, and supposes that the pitch volume is 1, and recording expansivity is ER _m, the expansivity of spraying the moment foamed asphalt is ER _a, injection rate remains unchanged.With course of injection (time 0 → t _s) be divided into the n five equilibrium, arbitrarily

In time period, the foamed asphalt volume that ejects does

To spraying the t that finishes _sConstantly, the volume decay does

Then spray and finish t _sVolume constantly

${\mathrm{ER}}_m=\frac{{\mathrm{ER}}_a}{n}\&CenterDot;\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{Exp}(-\frac{\mathrm{<figure-callout\; id="2"\; label="Ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">Ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;\frac{n-i}{n}\&CenterDot;t_s),$ Promptly

${\mathrm{ER}}_m=\frac{{\mathrm{ER}}_a}{n}\&CenterDot;[\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;\frac{n-1}{n}{t}_s)+\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;\frac{n-2}{n}{t}_s)+...+\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;\frac{1}{n}{t}_s)+1].$

Following formula the right is a Geometric Sequence,

And q ≠ 1 is by the Geometric Sequence sum formula $S_n=\frac{a_1-a_n\&CenterDot;q}{1-q},$ :

${\mathrm{ER}}_m=\frac{{\mathrm{ER}}_a}{n}\&CenterDot;\frac{\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;\frac{n-1}{n}\&CenterDot;t_s)-\exp (\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;\frac{1}{n}\&CenterDot;t_s)}{1-\exp (\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;\frac{1}{n}\&CenterDot;t_s)}$

When n →+during ∞, have:

uses the limit that L is asked

type, and molecule denominator differentiate respectively gets:

$\underset{n\&RightArrow;\&infin;}{\mathrm{Lim}}\frac{\frac{1}{n}}{1-\mathrm{Exp}(\frac{\mathrm{<figure-callout\; id="2"\; label="Ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">Ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s\&CenterDot;\frac{1}{n})}=\underset{n\&RightArrow;\&infin;}{\mathrm{Lim}}\frac{-\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}}{\mathrm{Exp}(\frac{\mathrm{<figure-callout\; id="2"\; label="Ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">Ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s\&CenterDot;\frac{1}{n})\&CenterDot;\frac{\mathrm{<figure-callout\; id="2"\; label="Ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">Ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s\&CenterDot;\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}}=-\frac{{\mathrm{\&tau;}}_{1/2}}{\mathrm{<figure-callout\; id="2"\; label="Ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">Ln</figure-callout>}2}\&CenterDot;\frac{1}{t_s},$ Thereby

${\mathrm{ER}}_m={\mathrm{ER}}_a\&CenterDot;\frac{{\mathrm{\&tau;}}_{1/2}}{\mathrm{<figure-callout\; id="2"\; label="Ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">Ln</figure-callout>}2}\&CenterDot;\frac{1}{t_s}\&CenterDot;[1-\mathrm{Exp}(-\frac{\mathrm{<figure-callout\; id="2"\; label="Ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">Ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s)],$ Get ER _aGeneral formula be:

${\mathrm{ER}}_a={\mathrm{ER}}_m\&CenterDot;\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s/[1-\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s)]---\left(2\right)$

In the formula, ER _m, τ _1/2And t _sAll can record by frothing test.

The foaming experiment can be carried out according to " asphalt highway regeneration techniques standard " (JTG F41-2008) appendix E foamed asphalt frothing test:

Adopt asphalt foaming testing machine (as tieing up special root WLB-10) to make foamed asphalt, foamed asphalt is ejected in the special-purpose steel measuring tank that is heated to 75 ℃, record injecting time t _sAEI After End of Injection is measured measuring tank inner foam pitch maximum height, and the record foamed asphalt decays to the time of maximum volume one half, draws the expansivity ER of foamed asphalt _mAnd the half life period.

Method of the present invention utilizes foamed asphalt decay equation to accurately calculate the actual maximum swelling rate of foamed asphalt, has the more accurate advantage of convenience of calculation, result with respect to half method of estimation of Jenkins.

To identical frothing test data (ER _m, τ _1/2And t _s), calculate ER with method of the present invention _a, compare with the estimation result of calculation value of the method for Jenkins, see the following form 2.In the table 2, ER _aThe former draws data from Jenkins, and the latter is calculated by formula of the present invention (2).According to table 2, can find out: t _sBig more, τ _1/2More little, the decay of course of injection is just many more, ER _aAnd ER _mDifference is just big more.The resultant error of Jenkins method gained is bigger, and: as injecting time t _sBigger, half life period τ _1/2More hour, the difference of Jenkins method is big more.This just explains that the Jenkins method is along with t _sIncrease τ _1/2Reduce, error is increasing, and this will have a strong impact on the fiduciary level of expansivity index evaluation foamed asphalt performance.

Table 2ER _mWith ER _aRelation

To sum up; Method of the present invention has convenience of calculation, the accurate advantage of result; Thereby can be efficiently, confirm the foam characteristics of pitch rationally, accurately, for the selection of engineering medium pitch provides reliable foundation, preventing influences construction quality because of the error in judgement of asphalt foaming characteristic.And method of the present invention does not receive the restriction of foaming condition, for the ER that records under any foaming condition _m, τ _1/2And t _s, can try to achieve ER _a

As the further application of the method for the actual maximum swelling rate of definite foamed asphalt of the present invention, at the actual maximum swelling rate ER of definite foamed asphalt of the present invention _aThe basis of method on, the invention allows for a kind of method of foaming capacity of particularly advantageous definite foamed asphalt:

Energy is the key factor that influences the foamed asphalt physical property.In the asphalt foaming process, cabin Nei Shui runs into heated bitumen in foaming, and the instantaneous water vapor that changes into, the volume generation pressure that expands rapidly promotes the foamed asphalt ejection.Consider from the energy conversion angle,, make foamed asphalt store the partial heat energy (this part energy is defined as the foaming energy) of original heated bitumen, thereby reduced the merit of mixing and stirring the required work that gathers materials just through foaming process.

The foamed asphalt decay is the volume decay process of " foam ", also is the energy decay process of " foam ".Foaming moment, the foamed asphalt volume is maximum, and the foaming energy of storage is also maximum, and when the time was tending towards infinity, it no longer was the pitch that " foam " arranged that foamed asphalt is tending towards complete attenuation one-tenth, and just the stored foaming energy of foamed asphalt is tending towards whole releases.The foamed asphalt expansivity is big more, and the half life period is long more, and in other words, the foamed asphalt volume is big more, and fall time is long more, and energy stored is just many more, and foam characteristics is good more.Therefore, the present invention proposes the index of weighing the foaming capacity of foamed asphalt with foaming energy FE (Foam Energy) conduct of foamed asphalt, the energy FE that wherein foams can be defined as the foamed asphalt volume and fall time is long-pending, promptly

FE＝A ₁+A ₂ (3)。

Referring to Fig. 4, shown the energy decay in whole foaming and the decay process among Fig. 4, wherein A ₁Be the foaming energy decay process in the course of injection, A ₂It is the foaming energy decay process of AEI After End of Injection.

Calculate A respectively ₁And A ₂Be more complicated, but can calculate the foaming energy from definition, promptly the foamed asphalt of any time ejection all elapsed-time standards 0 →+∞, the expansivity ER of pitch _a→ 0 process, then:

$\mathrm{FE}=A_1+A_2$

$={\&Integral;}_0^{+\&infin;}\mathrm{ER}\left(t\right)\&CenterDot;\mathrm{dt}---\left(4\right)$

Be regarded as two kinds of different materials to foamed asphalt and pitch, in fact the foamed asphalt decay is similar with the radioelement decay: when the time was tending towards infinity, the radioelement decay was two or more new elements, and the quality of radioelement own is tending towards 0; When the time was tending towards infinity, the foamed asphalt decay was pitch and water, and the volume of foamed asphalt is tending towards 0.

Therefore, the standard of foamed asphalt decay equation and radioelement decay are similar, and the actual maximum swelling rate of pitch is ER _a, half life period τ _1/2Be a constant that has nothing to do with original state, promptly frothing test records the half life period that the half life period is exactly a foamed asphalt.Can set up thus suc as formula the decay of the standard shown in 5 equation:

$\mathrm{ER}\left(t\right)={\mathrm{ER}}_a\&CenterDot;\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t)---\left(5\right).$

With obtaining in formula (5) the substitution formula (4):

$\mathrm{FE}=A_1+A_2$

$={\&Integral;}_0^{+\&infin;}\mathrm{ER}\left(t\right)\&CenterDot;\mathrm{dt}$

$={\&Integral;}_0^{+\&infin;}[{\mathrm{ER}}_a\&CenterDot;\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t)]\&CenterDot;\mathrm{dt}$

$=\frac{{\mathrm{ER}}_a\&CenterDot;{\mathrm{\&tau;}}_{1/2}}{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}$

Be following formula (6):

$\mathrm{FE}=\frac{{\mathrm{ER}}_a\&CenterDot;{\mathrm{\&tau;}}_{1/2}}{\ln 2}---\left(6\right)$

In the formula 6, if use the maximum swelling rate ER that directly records in the practice _mAs actual maximum swelling rate ER _aIts result is very inaccurate, points out when the research asphalt foaming process as the Jenkins professor of South Africa Stellenbosch university in 1999, before measurement volumes in the process of air blown asphalt; Foamed asphalt has just declined, and causes the maximum swelling rate ER that measures like this _mBe not equal to actual expansivity ER _a, the asphalt foaming time-continuing process is long more, and the foamed asphalt half life period is short more, ER _mWith ER _aDifference big more, adopt ER _mReplace ER _aWith the best foaming of appreciable impact pitch Determination of Parameters.And if the employing ER that Jenkins proposed _aComputing method, computation process is complicated, and inefficiency also exists out of true as a result, the defective of restricted application simultaneously.But obviously, can very conveniently confirm the FE value accurately, thereby the foaming capacity of definite foamed asphalt that can be qualitative and quantitative based on the method for definite actual maximum swelling rate of the present invention.

Therefore, the present invention also provides a kind of method of foaming capacity of definite foamed asphalt, it is characterized in that comprising following steps:

1) carries out the foamed asphalt frothing test under the foaming condition arbitrarily, obtaining the measured value ER of the maximum swelling rate of foamed asphalt _m, half life period τ _1/2With injecting time t _s

2) according to following formula

${\mathrm{ER}}_a={\mathrm{ER}}_m\&CenterDot;\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s/[1-\exp (-\frac{\mathrm{<figure-callout\; id="2"\; label="ln"\; filenames="HSA00000478834700011.png,HSA00000478834700012.png"\; state="\{\{state\}\}">ln</figure-callout>}2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s)]---\left(2\right)$

Confirm the actual maximum swelling rate ER of foamed asphalt _a

3) confirm the foaming energy FE of foamed asphalt according to formula (6):

$\mathrm{FE}=\frac{{\mathrm{ER}}_a\&CenterDot;{\mathrm{\&tau;}}_{1/2}}{\ln 2}---\left(6\right);$

4) confirm the foaming capacity of foamed asphalt according to foaming energy FE.

Obviously, according to above-mentioned analysis, the value of foaming energy is big more, and the foaming capacity of foamed asphalt is strong more.

Therefore; For with a kind of foamed asphalt; Can obtain the one group foaming energy FE value of said foamed asphalt under one group of foaming condition; Through the one group of foaming energy FE value that relatively obtains, confirm best foaming energy FE value, should be best foaming condition by the pairing foaming condition of the best foaming energy FE value simultaneously.

The foaming energy FE value of foamed asphalt is big more, explains that the foaming capacity of foamed asphalt is strong more, just explains that also this foaming condition is best.

For different foamed asphalts, can confirm the best foaming energy of a plurality of foamed asphalts respectively, the best that relatively obtains foaming energy, the maximum pairing foamed asphalt of the best foaming energy value is the foaming pitch with best foaming capacity.

The present invention has at first proposed accurately to confirm the method for the actual maximum swelling rate of foamed asphalt; According to this actual maximum swelling rate the foaming capacity of the accurate assess foam pitch of a kind of qualitative, quantitative and the method for best foaming condition have been proposed again; Solved by virtue of experience rough definite bigger defective of being brought of error in the prior art; Have simple and convenient, easy to implement and accurate advantage, for engineering construction provides reliable basis.

Description of drawings

Shown in Figure 1 is the ER of Jenkins _aCalculate synoptic diagram;

Nomogram for the c value shown in Figure 2;

Shown in Figure 3 is the foaming process of pitch;

Shown in Figure 4 is the foaming energy diagram of pitch.

Embodiment

Below in conjunction with specific embodiment, the present invention is described further.Should be understood that following examples only are used to the present invention is described but not are used to limit scope of the present invention.

Embodiment 1:

Certain asphalt foaming test obtains test figure and is: ER _m=15, τ _1/2=15s, t _s=5s.

The method of Jenkins: table look-up 1 ER _a=16.98.

Method of the present invention: in EXCEL software,, promptly get 16.80 with test figure substitution formula 2.

Two kinds of methods all can be tried to achieve ER easily _aWith the inventive method gained data is benchmark, and two kinds of method gained results differ

Embodiment 2:

Certain asphalt foaming test obtains test figure and is: ER _m=12, τ _1/2=10s, t _s=5s.

The method of Jenkins: look into Fig. 2 and get c=0.83, by c=ER _m/ ER _a, get ER _a=14.46.

Method of the present invention: in EXCEL software,, promptly get 14.27 with test figure substitution formula 2.

Adopt the method for Jenkins, this group test figure need check in c by Fig. 2, calculates ER again _aLook into figure gained result certain error is arranged; With the inventive method gained data is benchmark, and two kinds of method gained results differ

Embodiment 3:

Certain asphalt foaming test obtains test figure and is: ER _m=12, τ _1/2=15s, t _s=5s.

The method of Jenkins: look into Fig. 2 and get c=0.91, by c=ER _m/ ER _a, get ER _a=13.19.

Method of the present invention: in EXCEL software,, promptly get 13.47 with test figure substitution formula 2.

Adopt the method for Jenkins, this group test figure need check in c by Fig. 2, calculates ER again _aLook into figure gained result certain error is arranged; With the inventive method gained data is benchmark, and two kinds of method gained results differ

Embodiment 4:

Certain asphalt foaming test obtains test figure and is: ER _m=12, τ _1/2=15s, t _s=6s.

The method of Jenkins: all do not have t among table 1 and Fig. 2 _sThe situation of=6s, thereby can't obtain ER _a

Method of the present invention: in EXCEL software,, promptly get 13.78 with test figure substitution formula 2.

Through the comparison of more specific embodiment, can find that the method for Jenkins can only be to the ER under the specified conditions _m, τ _1/2And t _sAsk ER _a, have bigger limitation.Work as ER _m, τ _1/2And t _sNumerical value can only be asked ER through the method for seeing Fig. 1 not in table 1 _a, have certain error.Work as τ _1/2When numerical value was not Fig. 2 horizontal ordinate mark numerical value, error had the trend of increase.Work as t _sWhen numerical value was not given 1,2,5 or the 10s of Fig. 2, this method can't be tried to achieve ER _a

Embodiment 5:

A, B and three kinds of pitches of C are carried out a series of frothing tests, injecting time t _sBe 5s, it is following to record test figure:

Table 3 asphalt foaming test figure

The FE maximal value of A pitch is 1358, corresponding 155 ℃ asphalt temperature and 3.5% water consumption, the best foaming parameter of Here it is A pitch.

The FE maximal value of B pitch is 402, corresponding 165 ℃ asphalt temperature and 3.0% water consumption, the best foaming parameter of Here it is B pitch.

The FE maximal value of C pitch is 624, corresponding 165 ℃ asphalt temperature and 3.0% water consumption, the best foaming parameter of Here it is C pitch.

According to the FE value, the foam performance quality of A, B, three kinds of pitches of C is followed successively by: A＞C＞B.

Though this paper describes out preferred embodiment of the present invention, the many changes that clearly can carry out to those skilled in the art and modification can not exceed the scope from broad aspect of the present invention.

Claims (3)

1. confirm the method for the actual maximum swelling rate of foamed asphalt, comprising:

1) carrying out foamed asphalt foaming experiment under the foaming condition arbitrarily, obtains the measured value ER of the maximum swelling rate of foamed asphalt _m, half life period τ _1/2With injecting time t _s

2) according to following formula

${\mathrm{ER}}_a={\mathrm{ER}}_m\&CenterDot;\frac{\ln 2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s/[1-\exp (-\frac{\ln 2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s)]---\left(2\right)$

Confirm the actual maximum swelling rate ER of foamed asphalt _a

2. the method for the foaming capacity of a definite foamed asphalt is characterized in that comprising following steps:

1) carries out the foamed asphalt frothing test under the foaming condition arbitrarily, obtaining the measured value ER of the maximum swelling rate of foamed asphalt _m, half life period τ _1/2With injecting time t _s

2) according to following formula

${\mathrm{ER}}_a={\mathrm{ER}}_m\&CenterDot;\frac{\ln 2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s/[1-\exp (-\frac{\ln 2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s)]---\left(2\right)$

Confirm the actual maximum swelling rate ER of foamed asphalt _a

3) confirm the foaming energy FE of foamed asphalt according to formula (6):

$\mathrm{FE}=\frac{{\mathrm{ER}}_a\&CenterDot;{\mathrm{\&tau;}}_{1/2}}{\ln 2}---\left(6\right);$

4) confirm the foaming capacity of foamed asphalt according to foaming energy FE.

3. the method for the best foaming condition of a definite foamed asphalt is characterized in that comprising following steps:

1) under one group of foaming condition, carries out the foamed asphalt frothing test, obtain the measured value ER of the one group maximum swelling rate of foamed asphalt under different foaming conditions _m, half life period τ _1/2With injecting time t _s

2) according to following formula

${\mathrm{ER}}_a={\mathrm{ER}}_m\&CenterDot;\frac{\ln 2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s/[1-\exp (-\frac{\ln 2}{{\mathrm{\&tau;}}_{1/2}}\&CenterDot;t_s)]---\left(2\right)$

Confirm the one group actual maximum swelling rate ER of foamed asphalt under different foaming conditions _a

3) confirm the one group foaming energy FE of foamed asphalt under different foaming conditions according to formula (6):

$\mathrm{FE}=\frac{{\mathrm{ER}}_a\&CenterDot;{\mathrm{\&tau;}}_{1/2}}{\ln 2}---\left(6\right);$

4) the one group of foaming energy FE that relatively obtains, the maximum pairing foaming condition of foaming energy is best foaming condition.

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