CN103033453A - Method for measuring voidage of asphalt concrete pavement core - Google Patents

Abstract

The invention relates to a method for measuring voidage of an asphalt concrete pavement core. The method is characterized by comprising the following steps of: respectively measuring the bulk density of an asphalt concrete pavement core sample and the maximum theoretical density of the asphalt concrete pavement core sample, and calculating the density according to a formula. The method for measuring voidage of the asphalt concrete pavement core is easy, convenient, feasible, real and reliable in data, low in cost and pollution-free and has high innovativeness.

Description

A kind of bituminous concrete pavement core voidage assay method

Technical field

The present invention relates to a kind of concrete road surface core parametric measurement method, relate in particular to bituminous concrete pavement core voidage assay method, be mainly used in the evaluation of road engineering field medium pitch surface layer.

Background technology

Voidage is to characterize the very important index of Asphalt Concrete Pavement Performance, also is simultaneously one of key factor that affects bituminous concrete pavement tenure of use.The mensuration of bituminous concrete pavement core voidage is the very general test of bituminous pavement quality testing, and assay method is different, and the voidage level of reflection is also variant.Science is bituminous concrete pavement core voidage assay method accurately, and for stability, fatigue resistance, rutting resistance and the Durability Status of objective evaluation bituminous concrete pavement, formulating rational asphalt pavement conserving decision-making has very large directive significance.

At present, only provide the theoretical maximum relative density of measuring asphalt with vacuum method or solvent method in " highway engineering pitch and Asphalt Mixture Experiment rules " (JTG E20-2011), thereby calculate the method for mixture gap rate.Yet all there is corresponding deficiency in these two kinds of methods.Solvent method is can further enter in the mineral aggregate clearance gap after by triclene asphalt membrane being dissolved, and it exists the compound actual volume to diminish, and maximum theory density becomes large problem, and trichloroethylene solvent harm operator ' s health, contaminated environment.The very difficult space of remaining silent of processing loose asphalt fully of vacuum method causes the result inaccurate.Prove that generally vacuum method is not suitable for measuring the theoretical maximum relative density of modified asphalt mixture both at home and abroad.

What be worth to propose is, for the on-the-spot concrete core sample that drills through from the road, each independent core reflects pavement behavior in the particular range, so each core is unique, does not have reproducibility.Therefore, bituminous concrete core voidage is measured the feature that will can not weaken and reduce by parallel experiment for single core, error at measurment based on bituminous concrete core voidage determination object, propose scientific and reasonable, realistic bituminous concrete core voidage assay method, instruct and use.How how the bituminous pavement that can not do parallel experiment is carried out the concrete core sample voidage and measure, existing standard does not clearly propose.Therefore, be badly in need of research and development a kind of easy and simple to handle, the scope of application is wide, accuracy is high, cost is low, pollute little bituminous concrete core assay method.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, provide that a kind of step is simple, equipment is simple, result's bituminous concrete pavement core voidage assay method accurately, reaches the purpose of asphalt pavement condition Scientific Assessment.

The present invention solves its technical matters and is achieved through the following technical solutions:

A kind of bituminous concrete pavement core voidage assay method is characterized in that: this assay method comprises the step of measuring respectively bituminous concrete pavement core bulk density and bituminous concrete pavement core maximum theory density, then by formula $\mathrm{VV}=(1-\frac{{\mathrm{\ρ}}_f}{{\mathrm{\ρ}}_t})\×100\%$ Calculate and get.

The step of described mensuration bituminous concrete pavement core maximum theory density is specially:

⑴. prepare a long handle steel spoon and two little basins that the interface is smooth, volume is no more than 1L, and number 1 ﹟ basin, 2 ﹟ basins;

⑵. weighing steel spoon adds the quality η of 1# basin ₁And quality η in the water ₂, weighing is used for measuring the quality η of the 2# basin of asphalt density ₆And quality η in the water ₇

⑶. the bituminous concrete pavement core is packed in the 1# basin of putting the steel spoon, and accurately weighing steel spoon adds the gross mass η that the 1# basin adds the bituminous concrete pavement core ₃, the 1# basin that then steel spoon and bituminous concrete pavement core will be housed is put into the baking oven identical with the asphalt mixture mixing temperature and is toasted, and will put into baking oven with the pitch of bituminous concrete core same type simultaneously;

⑷. after the bituminous concrete pavement core is fully loose, carefully the pitch core is smash loosely with the steel spoon, the pitches that will melt are in a large number simultaneously poured in 1# basin, the 2# basin simultaneously, and 1# basin medium pitch covers fully and exceeds loose core surface 2cm, the 1# basin stirs 3min with the steel spoon, discharges bubble;

Then 1# basin, 2# basin are put into the constant temperature oven that temperature is lower than 15～20 ℃ of asphalt mixture mixing temperature of the same type, the 1# basin stirs 1 time every 20min, stir altogether 2 times, each 3min that stirs, the 2# basin leaves standstill in baking oven puts the 60min observation, without bubble, soon 1# basin, 2# basin take out and at room temperature place 12～24h such as the surface;

⑸. the gross mass η of the 1# basin of steel spoon, pitch and bituminous concrete pavement core is equipped with in weighing ₄And quality η in the water ₅

⑹. the gross mass η of the 2# basin of pitch is equipped with in weighing ₈And quality η in the water ₉

⑺. calculate bituminous concrete core theoretical maximum relative density ρ _t:

${\mathrm{\ρ}}_t=\frac{{\mathrm{\η}}_3-{\mathrm{\η}}_1}{{\mathrm{\η}}_4-{\mathrm{\η}}_5-({\mathrm{\η}}_1-{\mathrm{\η}}_2)-({\mathrm{\η}}_4-{\mathrm{\η}}_3)/{\mathrm{\ρ}}_a}$

${\mathrm{\ρ}}_a=\frac{{\mathrm{\η}}_8-{\mathrm{\η}}_6}{{\mathrm{\η}}_8-{\mathrm{\η}}_9-({\mathrm{\η}}_6-{\mathrm{\η}}_7)}.$

The step of the bulk specific gravity of described mensuration bituminous concrete pavement core is specially:

⑴. remove the floating grain in bituminous concrete pavement core surface, take by weighing the aerial quality η of dry test specimen _a

⑵. place the basket that immerses spill box to be immersed in the water 3-5min the bituminous concrete pavement core, take by weighing quality η in the water of test specimen _w

⑶. from water, take out the bituminous concrete pavement core, wipe gently surface water with the clean soft wet towel of wringing out, must not siphon away the water in the space simultaneously, take by weighing the surface drying quality η of bituminous concrete pavement core _f, take out the water surface from test specimen and finish to be no more than 5s, no longer wiping of the water that flows out in the weighing process to wiping;

⑷. according to formula

Calculate the bulk specific gravity of bituminous concrete pavement core.

Advantage of the present invention and beneficial effect are:

1. bituminous concrete pavement core voidage assay method of the present invention, take with the pitch of bituminous concrete pavement core same type as medium, adopt the mode of high-temperature stirring, the mixture gap rate is approached equals zero, reached the effect of real simulation, thereby the test findings accuracy is high.

2. bituminous concrete pavement core voidage assay method of the present invention, test instrument is simple, and is easy to operate, and all kinds bituminous concrete core all can use the method, and suitable environment and scope are wide.

3. bituminous concrete pavement core voidage assay method of the present invention need not to use special negative-pressure container or triclene class chemical solvent, and experimentation cost is low, and environmental pollution is little, and it is healthy not affect testing crew.

4. bituminous concrete pavement core voidage assay method of the present invention, simple and easy to do, data are true and reliable, and cost is low, and is pollution-free, is a kind of bituminous concrete pavement core voidage assay method with higher innovation.

Embodiment

The invention will be further described below by specific embodiment, and following examples are descriptive, is not determinate, can not limit protection scope of the present invention with this.

A kind of bituminous concrete pavement core voidage assay method, this assay method comprises the step of measuring respectively bituminous concrete pavement core bulk density and bituminous concrete pavement core maximum theory density, then by formula $\mathrm{VV}=(1-\frac{{\mathrm{\ρ}}_f}{{\mathrm{\ρ}}_t})\×100\%$ Calculate and get.

Wherein, measure the step of bituminous concrete pavement core maximum theory density, be specially:

⑴. prepare a long handle steel spoon and two little basins that the interface is smooth, volume is no more than 1L, and number 1 ﹟ basin, 2 ﹟ basins;

⑵. weighing steel spoon adds the quality η of 1# basin ₁And quality η in the water ₂, weighing is used for measuring the quality η of the 2# basin of asphalt density ₆And quality η in the water ₇

⑶. the bituminous concrete pavement core is packed in the 1# basin of putting the steel spoon, and accurately weighing steel spoon adds the gross mass η that the 1# basin adds the bituminous concrete pavement core ₃, the 1# basin that then steel spoon and bituminous concrete pavement core will be housed is put into the baking oven identical with the asphalt mixture mixing temperature and is toasted, and will put into baking oven with the pitch of bituminous concrete core same type simultaneously;

⑷. after the bituminous concrete pavement core is fully loose, carefully the pitch core is smash loosely with the steel spoon, the pitches that will melt are in a large number simultaneously poured in 1# basin, the 2# basin simultaneously, and 1# basin medium pitch covers fully and exceeds loose core surface 2cm, the 1# basin stirs 3min with the steel spoon, discharges bubble;

Then 1# basin, 2# basin are put into the constant temperature oven that temperature is lower than 15～20 ℃ of asphalt mixture mixing temperature of the same type, the 1# basin stirs 1 time every 20min, stir altogether 2 times, each 3min that stirs, the 2# basin leaves standstill in baking oven puts the 60min observation, without bubble, soon 1# basin, 2# basin take out and at room temperature place 12～24h such as the surface;

⑸. the gross mass η of the 1# basin of steel spoon, pitch and bituminous concrete pavement core is equipped with in weighing ₄And quality η in the water ₅

⑹. the gross mass η of the 2# basin of pitch is equipped with in weighing ₈And quality η in the water ₉

⑺. calculate bituminous concrete core theoretical maximum relative density ρ _t:

${\mathrm{\ρ}}_t=\frac{{\mathrm{\η}}_3-{\mathrm{\η}}_1}{{\mathrm{\η}}_4-{\mathrm{\η}}_5-({\mathrm{\η}}_1-{\mathrm{\η}}_2)-({\mathrm{\η}}_4-{\mathrm{\η}}_3)/{\mathrm{\ρ}}_a}$

${\mathrm{\ρ}}_a=\frac{{\mathrm{\η}}_8-{\mathrm{\η}}_6}{{\mathrm{\η}}_8-{\mathrm{\η}}_9-({\mathrm{\η}}_6-{\mathrm{\η}}_7)}.$

Measure the step of the bulk specific gravity of bituminous concrete pavement core, be specially:

⑴. remove the floating grain in bituminous concrete pavement core surface, take by weighing the aerial quality η of dry test specimen _a

⑵. place the basket that immerses spill box to be immersed in the water 3-5min the bituminous concrete pavement core, take by weighing quality η in the water of test specimen _w

⑶. from water, take out the bituminous concrete pavement core, wipe gently surface water with the clean soft wet towel of wringing out, must not siphon away simultaneously the water in the space, take by weighing the surface drying quality η f of bituminous concrete pavement core, take out the water surface from test specimen and finish to be no more than 5s, no longer wiping of the water that flows out in the weighing process to wiping;

⑷. according to formula

Calculate the bulk specific gravity of bituminous concrete pavement core.

Concrete test data is:

Drill through three bituminous concrete pavement cores from different bituminous pavements, called after core-1, core-2, core-3.Core-1 is that rubber powder modified asphalt concrete core sample, core-2 are 70# matrix pitch concrete core sample for SBS modified asphalt concrete core, core-3.

Adopt said method, measure each bituminous concrete pavement core bulk specific gravity:

	Dry mass η a	Quality η in the water w	Surface drying quality η f	Bulk specific gravity η f
					Core-1	425.9	249.6	428.1	2.386
Core-2	544.5	320.2	547.1	2.400
					Core-3	400.8	238.4	402.5	2.442

Adopt said determination bituminous concrete core theoretical maximum relative density:

Calculate this bituminous concrete core-1 voidage $\mathrm{VV}=(1-\frac{{\mathrm{\ρ}}_f}{{\mathrm{\ρ}}_t})\×100\%=(1-\frac{2.386}{2.572})\×100\%=7.23$

Calculate this bituminous concrete core-2 voidage $\mathrm{VV}=(1-\frac{{\mathrm{\ρ}}_f}{{\mathrm{\ρ}}_t})\×100\%=(1-\frac{2.400}{2.535})\×100\%=5.33$

Calculate this bituminous concrete core-3 voidage $\mathrm{VV}=(1-\frac{{\mathrm{\ρ}}_f}{{\mathrm{\ρ}}_t})\×100\%=(1-\frac{2.442}{2.552})\×100\%=4.31$

Although disclosed embodiments of the invention for the purpose of illustration, but it will be appreciated by those skilled in the art that, in the spirit and scope that do not break away from the present invention and claims, various replacements, variation and modification all are possible, and therefore scope of the present invention is not limited to the disclosed content of embodiment.

Claims (3)

1. bituminous concrete pavement core voidage assay method, it is characterized in that: this assay method comprises the step of measuring respectively bituminous concrete pavement core bulk density and bituminous concrete pavement core maximum theory density, then by formula

Calculate and get.

2. bituminous concrete pavement core voidage assay method as claimed in claim 1, it is characterized in that: the step of described mensuration bituminous concrete pavement core maximum theory density is specially:

⑴. prepare a long handle steel spoon and two little basins that the interface is smooth, volume is no more than 1L, and number 1 ﹟ basin, 2 ﹟ basins;

⑵. weighing steel spoon adds the quality η of 1# basin ₁And quality η in the water ₂, weighing is used for measuring the quality η of the 2# basin of asphalt density ₆And quality η in the water ₇

⑶. the bituminous concrete pavement core is packed in the 1# basin of putting the steel spoon, and accurately weighing steel spoon adds the gross mass η that the 1# basin adds the bituminous concrete pavement core ₃, the 1# basin that then steel spoon and bituminous concrete pavement core will be housed is put into the baking oven identical with the asphalt mixture mixing temperature and is toasted, and will put into baking oven with the pitch of bituminous concrete core same type simultaneously;

⑷. after the bituminous concrete pavement core is fully loose, carefully the pitch core is smash loosely with the steel spoon, the pitches that will melt are in a large number simultaneously poured in 1# basin, the 2# basin simultaneously, and 1# basin medium pitch covers fully and exceeds loose core surface 2cm, the 1# basin stirs 3min with the steel spoon, discharges bubble;

Then 1# basin, 2# basin are put into the constant temperature oven that temperature is lower than 15～20 ℃ of asphalt mixture mixing temperature of the same type, the 1# basin stirs 1 time every 20min, stir altogether 2 times, each 3min that stirs, the 2# basin leaves standstill in baking oven puts the 60min observation, without bubble, soon 1# basin, 2# basin take out and at room temperature place 12～24h such as the surface;

⑸. the gross mass η of the 1# basin of steel spoon, pitch and bituminous concrete pavement core is equipped with in weighing ₄And quality η in the water ₅

⑹. the gross mass η of the 2# basin of pitch is equipped with in weighing ₈And quality η in the water ₉

⑺. calculate bituminous concrete core theoretical maximum relative density ρ _t:

3. bituminous concrete pavement core voidage assay method as claimed in claim 1, it is characterized in that: the step of the bulk specific gravity of described mensuration bituminous concrete pavement core is specially:

⑴. remove the floating grain in bituminous concrete pavement core surface, take by weighing the aerial quality η of dry test specimen _a

⑵. place the basket that immerses spill box to be immersed in the water 3-5min the bituminous concrete pavement core, take by weighing quality η in the water of test specimen _w

⑶. from water, take out the bituminous concrete pavement core, wipe gently surface water with the clean soft wet towel of wringing out, must not siphon away simultaneously the water in the space, take by weighing the surface drying quality η f of bituminous concrete pavement core, take out the water surface from test specimen and finish to be no more than 5s, no longer wiping of the water that flows out in the weighing process to wiping;

⑷. according to formula

Calculate the bulk specific gravity of bituminous concrete pavement core.