CN102809645B - Method for testing high-temperature performance difference of asphalt mixtures after crushing of coarse aggregates - Google Patents

Abstract

The invention discloses a method for testing high-temperature performance differences of asphalt mixtures after crushing of coarse aggregates, and aims to evaluate the performance differences of the asphalt mixtures before and after crushing of the coarse aggregates. The method includes extracting four to six paved and ground cylindrical core samples from a construction field of an asphalt road surface; measuring bulk relative density and Marshall stability of each core sample; extracting asphalt mixtures from a mixing plant to form four to six test pieces; taking cores of the test pieces and cutting the cores into cylindrical indoor test pieces in the sizes the same with those of the core samples from the field; testing Marshall stability of each cylindrical indoor test piece; and computing to obtain a ratio of the Marshall stability of the cylindrical test samples from the field to the Marshall stability of the cylindrical indoor test piece. The batches and the types of the asphalt mixtures extracted from the mixing plant are identical to those of the cylindrical core samples. Compared with the prior art, the method has the advantages that the differences of gradation and high-temperature deformation resistance, water stability and low-temperature crack resistance of the asphalt mixtures before and after the coarse aggregates in the mixtures are crushed in a construction process are tested, and the performance differences of the asphalt mixtures before and after the aggregates are crushed are evaluated.

Description

The method of testing of asphalt mixture after crushing coarse aggregates high-temperature behavior otherness

The application is the divisional application of 200910105919.6, and the applying date of original application is on March 2nd, 2009, and application number 200910105919.6, invention and created name is the method for testing of pitch mixed performance after crushing coarse aggregates.

Technical field

The present invention relates to a kind of method of testing of road construction of highway engineering material property, particularly a kind ofly to select due to starting material or construction technology causes the method for testing of asphalt mixture after crushing coarse aggregates high-temperature behavior otherness.

Background technology

The associated specifications (code) such as existing " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000), " standard specification for construction and acceptance of highway asphalt pavement " (JTGF40-2004), " bituminous pavement design for highway specification " (JTGD50-2006), " Of Road Engineering Quality Checking And Evaluation standard " (JTGF80-2004) does not all relate to the evaluation method of performance of asphalt mixture after crushing coarse aggregates in construction.But after crushing coarse aggregates, the performance of asphalt there occurs great change, has had a strong impact on performance of asphalt mixture and using character, therefore proposes new requirement to the test of asphalt.

Summary of the invention

The object of this invention is to provide a kind of method of testing of asphalt mixture after crushing coarse aggregates high-temperature behavior otherness, the technical matters that solve evaluates the otherness of the forward and backward performance of asphalt mixture of crushing coarse aggregates.

The present invention is by the following technical solutions: a kind of method of testing of performance of asphalt mixture, comprise the following steps: one, extract 4 ~ 6 complete right cylinder cores that pave and roll from asphalt pavement construction scene, measure the bulk specific gravity of core, measure core 60 DEG C of Marshall stability MS; Two, same batch, asphalt of the same type with working-yard is extracted from batching plant, after being heated to on-the-spot paving material in an oven, by the average relative density of on-the-spot sample, shaping 4 ~ 6 test specimens, after ambient temperatare puts 2h, get core and cut into the indoor test specimen with the right cylinder of on-the-spot core equidimension, test specimen 60 DEG C of Marshall stability MS ' in measuring cell; Three, the scene obtained and indoor Marshall stability ratio is calculated

Method of the present invention randomly draws 4 ~ 6 complete right cylinder cores that pave and roll, for extracting from cutting optimal, middle surface layer or upper layer from asphalt pavement construction scene.

When method of the present invention measures the bulk specific gravity of core, measure diameter and height.

A kind of method of testing of performance of asphalt mixture, comprise the following steps: one, extract 8 ~ 12 complete right cylinder cores that pave and roll from asphalt pavement construction scene, sample is divided into 2 groups at random, often organizes 4 ~ 6, first group of sample is placed on platform, at room temperature saves backup; Two, by second group of sample full water 15min under 98.3kPa ~ 98.7kPa vacuum condition, 0.5h is placed in water at atmospheric pressure, take out sample and put into polybag, add the water of 10mL, tighten sack, sample is put into the freezing 15h ~ 17h of constant temperature refrigerator, keep temperature to be-18 DEG C, after being taken out by sample, put into the Water Tank with Temp.-controlled of 60 DEG C ± 0.5 DEG C immediately, remove polybag, insulation 24h; Three, again first group and second group of sample all being immersed temperature is be greater than 2h in the Water Tank with Temp.-controlled of 25 DEG C ± 0.5 DEG C; Four, take out sample and carry out diametral compression test by the loading speed of 50mm/min immediately, obtain the peak load P tested, obtain the cleavage strength of 2 groups of each samples respectively: five, freeze-thaw split strength ratio is obtained

Method of the present invention randomly draws 8 ~ 12 complete right cylinder cores that pave and roll, for extracting from cutting optimal, middle surface layer or upper layer from asphalt pavement construction scene.

During the right cylinder core that method of the present invention paves and roll complete from asphalt pavement construction scene extraction 8 ~ 12, measure diameter and height.

A kind of method of testing of performance of asphalt mixture, comprise the following steps: one, extract 4 ~ 6 cores from asphalt pavement construction scene, measure core bulk specific gravity, temperature is-10 DEG C ± 0.5 DEG C, carry out diametral compression test by the loading speed of 1mm/min, obtain the cleavage strength R of each sample _t1; Two, same batch, compound of the same type with working-yard is extracted from batching plant, after being heated to on-the-spot paving material in an oven, by the average of on-the-spot sample relative density, shaping 4 ~ 6 test specimens, after ambient temperatare puts 2h, get core and cut into the indoor test specimen with the right cylinder of on-the-spot core equidimension, temperature is-10 DEG C ± 0.5 DEG C, carry out diametral compression test by the loading speed of 1mm/min, obtain the cleavage strength R of sample _t2; Three, on-the-spot and indoor Ratio of split strength is obtained $K=\frac{R_{T1}}{R_{T2}}\·100.$

Method of the present invention randomly draws 4 ~ 6 complete right cylinder cores that pave and roll, for extracting from cutting optimal, middle surface layer or upper layer from asphalt pavement construction scene.

When method of the present invention measures the bulk specific gravity of core, measure diameter and height.

A kind of method of testing of performance of asphalt mixture, comprise the following steps: one, on-the-spot at asphalt pavement construction, from paver screw distributing device, randomly draw 1.5kg ~ 2kg asphalt, from compound, isolate pitch, obtain the mixing mineral aggregate after isolating pitch; Two, sieving isolating the mixing mineral aggregate after pitch, measuring nominal maximum particle diameter sieve aperture percent of pass P _max, %, 4.75mm sieve aperture percent of pass P _4.75, %, 2.36mm sieve aperture percent of pass P _2.36, %, 0.075mm sieve aperture percent of pass P _0.075, %; Three, same position at the construction field (site), asphalt after the decking and rolling of cutting 50cm × 50cm area, places in micro-wave oven and heats 10min ~ 15min, extract 1.5kg ~ 2kg compound from middle part, isolate pitch, obtain the scene mixing mineral aggregate after isolating pitch; Four, isolate the scene mixing mineral aggregate after pitch to sieve, measure nominal maximum particle diameter sieve aperture percent of pass P ' _max, %, 4.75mm sieve aperture percent of pass P ' _4.75, %, 2.36mm sieve aperture percent of pass P ' _2.36, %, sieve aperture percent of pass P ' _0.075, %; Five, calculate respectively coarse aggregate in compound crushed after, the aberration rate (%) of nominal maximum particle diameter, 4.75mm, 2.36mm, 0.075mm key sieve percent of pass in mixing mineral aggregate: $K_{\max }=\frac{P_{\max }^{\′}}{P_{\max }}\·100;$ $K_{4.75}=\frac{P_{4.75}^{\′}}{P_{4.75}}\·100,$ $K_{2.36}=\frac{P_{2.36}^{\′}}{P_{2.36}}\·100,$ $K_{0.075}=\frac{P_{0.075}^{\′}}{P_{0.075}}\·100.$

The present invention compared with prior art, test in work progress, the otherness of the crushed forward and backward asphalt mixture gradation of the coarse aggregate in compound, anti-deforming performance, water stability and crack resistance at low-temperature, solves the difference appraisal problem of the forward and backward performance of asphalt mixture of crushing coarse aggregates.

Embodiment

Below in conjunction with embodiment, the present invention is described in further detail.The evaluation method of performance of asphalt mixture of the present invention, comprises and testing asphalt mixture after crushing coarse aggregates grating variability, anti-deforming performance, water stability, cryogenic property.The variability of grating is represented with the ratio of crushing coarse aggregates forward and backward compound key sieve percent of pass; The otherness of the forward and backward compound high-temperature behavior of crushing coarse aggregates is represented with on-the-spot and indoor Marshall stability ratio; The otherness that crushing coarse aggregates forward and backward compound water is stable is represented by the freeze-thaw split strength ratio of on-the-spot core; The otherness of the forward and backward compound cryogenic property of crushing coarse aggregates is represented with on-the-spot and indoor Ratio of split strength.

The method of testing of asphalt mixture after crushing coarse aggregates grating variability, comprises the following steps:

One, on-the-spot at asphalt pavement construction, 1.5kg ~ 2kg asphalt is randomly drawed from paver screw distributing device, from compound, isolate pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0722-1993 test method, obtain the mixing mineral aggregate after isolating pitch;

Two, sieving isolating the mixing mineral aggregate after pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0725-2000 test method, measuring nominal maximum particle diameter sieve aperture percent of pass P _max, %, 4.75mm sieve aperture percent of pass P _4.75, %, 2.36mm sieve aperture percent of pass P _2.36, %, 0.075mm sieve aperture percent of pass P _0.075, %;

Three, same position at the construction field (site), asphalt after the decking and rolling of cutting 50cm × 50cm area, place in micro-wave oven and heat 10min ~ 15min, after loose to compound, 1.5kg ~ 2kg compound is extracted from middle part, from compound, isolate pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0722-1993 test method, obtain the scene mixing mineral aggregate after isolating pitch;

Four, sieving isolating the scene mixing mineral aggregate after pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0725-2000 test method, measuring nominal maximum particle diameter sieve aperture percent of pass P ' _max, %, 4.75mm sieve aperture percent of pass P ' _4.75, %, 2.36mm sieve aperture percent of pass P ' _2.36, %, sieve aperture percent of pass P ' _0.075, %;

Five, calculate respectively as follows coarse aggregate in compound crushed after, the aberration rate (%) of nominal maximum particle diameter, 4.75mm, 2.36mm, 0.075mm key sieve percent of pass in mixing mineral aggregate: $K_{\max }=\frac{P_{\max }^{\′}}{P_{\max }}\·100;$ $K_{4.75}=\frac{P_{4.75}^{\′}}{P_{4.75}}\·100,$ $K_{2.36}=\frac{P_{2.36}^{\′}}{P_{2.36}}\·100,$ $K_{0.075}=\frac{P_{0.075}^{\′}}{P_{0.075}}\·100.$

The method of testing of asphalt mixture after crushing coarse aggregates anti-deforming performance, comprises the following steps:

One, the right cylinder core of 4 ~ 6 the complete cutting optimal that pave and roll, middle surface layer or upper layers is randomly drawed from asphalt pavement construction scene, press the diameter of " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0705-2000 determination of test method core, height and bulk specific gravity, by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0709-2000 determination of test method core 60 DEG C of Marshall stability MS, kN;

Two, same batch, asphalt of the same type with working-yard is extracted from batching plant, after being heated to on-the-spot paving material in an oven, by the average relative density of on-the-spot sample, shaping 4 ~ 6 test specimens of 4140-B type rotary compactor are produced with the U.S., after ambient temperatare puts 2h, get core and cut into the indoor test specimen with the right cylinder of on-the-spot core equidimension, by the indoor test specimen core of " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0709-2000 determination of test method 60 DEG C of Marshall stability MS ', kN;

Three, the scene obtained and indoor Marshall stability ratio is calculated with the size of K value, asphalt mixture after crushing coarse aggregates anti-deforming performance is described, large on the impact of compound high-temperature behavior after K value little explanation crushing coarse aggregates, K value is little on the impact of compound high-temperature behavior after crushing coarse aggregates is described greatly, thus after crushing gathering materials, asphalt anti-deforming performance has a quantitative description; Because core height, diameter are different from " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0709-2000 test method, therefore, core height, diameter must be indicated in test findings.

The method of testing of asphalt mixture after crushing coarse aggregates water stability, comprises the following steps:

One, the right cylinder core of 8 ~ 12 the complete cutting optimal that pave and roll, middle surface layer or upper layers is randomly drawed from asphalt pavement construction scene, measure the diameter D of sample, height h, sample is divided into 2 groups at random, often organize 4 ~ 6, first group of sample is placed on platform, at room temperature saves backup;

Two, second group of sample is pressed " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0717-1993 test method, full water 15min under 98.3kPa ~ 98.7kPa vacuum condition, open valve, recover normal pressure, sample places 0.5h in water, take out sample and put into polybag, add the water of 10mL, tighten sack, sample is put into the freezing 15h ~ 17h of constant temperature refrigerator, keep temperature to be-18 DEG C, after sample is taken out, put into the Water Tank with Temp.-controlled of 60 DEG C ± 0.5 DEG C immediately, remove polybag, insulation 24h;

Three, first group and second group of sample all being immersed temperature is be greater than 2h in the Water Tank with Temp.-controlled of 25 DEG C ± 0.5 DEG C;

Four, sample is taken out immediately by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0716-1993 test method, diametral compression test is carried out by the loading speed of 50mm/min, obtain the peak load P tested, obtain the cleavage strength of 2 groups of each samples by following formula respectively:

${\mathrm{\σ}}_1=\frac{2P_1}{\mathrm{\π}{h}_1{D}_1}$

${\mathrm{\σ}}_2=\frac{2P_2}{\mathrm{\π}{h}_2{D}_2}$

In formula, σ ₁for not carrying out the cleavage strength of first group of sample of Frozen-thawed cycled, MPa; P ₁be the maximal value of the trial load of first group of sample, MPa; h ₁be the height of first group of sample, mm; D ₁be the diameter of first group of sample, mm.σ ₂for standing the cleavage strength of second group of sample of Frozen-thawed cycled, MPa; P ₂be the maximal value of the trial load of second group of sample, MPa; h ₂be the height of second group of sample, mm; D ₂be the diameter of second group of sample, mm;

Five, freeze-thaw split strength ratio is obtained with the size of TSR value, asphalt mixture after crushing coarse aggregates water stability is described, TSR value is little on the impact of compound water stability after crushing coarse aggregates is described greatly, TSR value novel is large on the impact of compound water stability after speaking frankly bright crushing coarse aggregates, thus the description to asphalt mixture after crushing coarse aggregates water stability quantitative.

The method of testing of asphalt mixture after crushing coarse aggregates cryogenic property, comprises the following steps:

One, the core of 4 ~ 6 cutting optimal, middle surface layer or upper layer is randomly drawed from asphalt pavement construction scene, press the diameter of " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0705-2000 determination of test method core, height and bulk specific gravity, again by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0716-1993 test method, test temperature is-10 DEG C ± 0.5 DEG C, carry out diametral compression test by the loading speed of 1mm/min, obtain the cleavage strength R of each sample _t1;

Two, extract and same batch of working-yard from batching plant, compound of the same type, after being heated to on-the-spot paving material in an oven, by the average of on-the-spot sample relative density, shaping 4 ~ 6 test specimens of 4140-B type rotary compactor are produced with the U.S., after ambient temperatare puts 2h, get core and cut into the indoor test specimen with the right cylinder of on-the-spot core equidimension, by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0716-1993 test method, test temperature is-10 DEG C ± 0.5 DEG C, diametral compression test is carried out by the loading speed of 1mm/min, obtain the cleavage strength R of sample _t2,

Three, on-the-spot and indoor Ratio of split strength is obtained with the size of K value, asphalt mixture after crushing coarse aggregates cryogenic property is described, K value is little on the impact of low temperature performance of asphalt after crushing coarse aggregates is described greatly, large on the impact of low temperature performance of asphalt after the little explanation crushing coarse aggregates of K value, thus have a quantitative description to asphalt mixture after crushing coarse aggregates cryogenic property; Because core height, diameter are different from " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0716-1993 test method, therefore, core height, diameter must be indicated in test findings.

Embodiment 1, the test of asphalt mixture after crushing coarse aggregates grating variability

One, in certain highway, surface layer have employed AC-20C type asphalt, the crush values of ls coarse aggregate is 24%, the content of flat-elongated particles is 16%, all meet " standard specification for construction and acceptance of highway asphalt pavement " (JTGF40-2004) and show 4.8.2 to coarse aggregate quality technology used for asphalt mixture requirement, close to the upper limit of allowed band;

Two, at the construction field (site), from paver screw distributing device, randomly draw 2kg compound, from compound, isolate pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0722-1993 test method;

Three, sieving isolating the mixing mineral aggregate after pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0725-2000 test method, measuring nominal maximum particle diameter sieve aperture percent of pass P _max, %, 4.75mm sieve aperture percent of pass P _4.75, %, 2.36mm sieve aperture percent of pass P _2.36, %; 0.075mm sieve aperture percent of pass P _0.075, %, test findings is in table 1;

Four, same position at the construction field (site), cut the asphalt after the decking and rolling of 50cm × 50cm area, place in micro-wave oven and heated 10min, after loose to asphalt, extract 2kg compound from middle part, from asphalt, isolate pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0722-1993 test method;

Five, sieving isolating the scene mixing mineral aggregate after pitch by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0725-2000 test method, measuring nominal maximum particle diameter sieve aperture percent of pass P ' _max, %, 4.75mm sieve aperture percent of pass P ' _4.75, %, 2.36mm sieve aperture percent of pass P ' _2.36, %, sieve aperture percent of pass P ' _0.075, %, test findings is in table 1;

Six, calculate respectively as follows coarse aggregate in compound crushed after, the aberration rate (%) of the key sieve percent of pass such as nominal maximum particle diameter, 4.75mm, 2.36mm, 0.075mm in mixing mineral aggregate: $K_{\max }=\frac{P_{\max }^{\′}}{P_{\max }}\·100,$ $K_{4.75}=\frac{P_{4.75}^{\′}}{P_{4.75}}\·100,$ $K_{2.36}=\frac{P_{2.36}^{\′}}{P_{2.36}}\·100,$ $K_{0.075}=\frac{P_{0.075}^{\′}}{P_{0.075}}\·100,$ Result of calculation is in table 1.From table 1, asphalt is after paving, rolling, the percent of pass of each key sieve of mixing mineral aggregate increases all to some extent, changing maximum is 4.75mm sieve aperture, this sieve aperture percent of pass adds 6.7%, illustrates that coarse aggregate particle mass ratio after paving, rolling that former particle diameter is greater than 4.75mm decreases 6.7%.In other words, although the ls coarse aggregate that this project uses can meet the quality technology requirement of specification, still have account for mixing mineral aggregate gross mass 6.7% coarse aggregate crushed in work progress.

Embodiment 2, the performance test of asphalt mixture after crushing coarse aggregates anti-deforming

One, in certain identical with example 1 highway, surface layer have employed AC-20C type asphalt, the crush values of ls coarse aggregate is 24%, the content of flat-elongated particles is 16%, all meet " standard specification for construction and acceptance of highway asphalt pavement " (JTGF40-2004) and show 4.8.2 to coarse aggregate quality technology used for asphalt mixture requirement, close to the upper limit of allowed band;

Two, at the construction field (site), randomly draw 6 cores, first, press " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0705-2000 determination of test method diameter of core, height and bulk specific gravity, test findings is in table 1, then, by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0709-2000 determination of test method core 60 DEG C of Marshall stability MS, test findings is in table 3;

Three, same batch, compound of the same type with working-yard is extracted from batching plant, after being heated to on-the-spot paving material in an oven, by the average of on-the-spot sample relative density, with shaping 6 test specimens of rotary compactor, after ambient temperatare puts 2h, get core and cut into the right cylinder test specimen with on-the-spot core equidimension, press " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0709-2000 determination of test method core 60 DEG C of Marshall stability MS ', test findings is in table 2;

Four, the scene asked and indoor Marshall stability ratio the results are shown in Table 2.Test findings shows, in construction coarse aggregate crushed after, compound Marshall stability reduces 32.4%, makes a significant impact after crushing coarse aggregates is described on compound anti-deforming performance;

Embodiment 3, asphalt mixture after crushing coarse aggregates water stability is tested

One, in certain identical with example 1 highway, surface layer have employed AC-20C type asphalt, the crush values of ls coarse aggregate is 24%, the content of flat-elongated particles is 16%, all meet " standard specification for construction and acceptance of highway asphalt pavement " (JTGF40-2004) and show 4.8.2 to coarse aggregate quality technology used for asphalt mixture requirement, close to the upper limit of allowed band;

Two, at the construction field (site), randomly drawed 12 middle surface layer cores, determine the diameter D of sample, height h, sample, in table 3, is divided into 2 groups by test findings at random, often organizes 6, is placed on platform, at room temperature saves backup first group of sample;

Three, second group of sample is pressed " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0717-1993 test method, full water 15min under 98.3kPa ~ 98.7kPa vacuum condition, open valve, recover normal pressure, sample places 0.5h in water.Take out sample and put into polybag, add the water of 10mL, tighten sack, sample is put into constant temperature refrigerator freezing, keep temperature to be-18 DEG C, 15h ~ 17h.After sample is taken out, put into the Water Tank with Temp.-controlled of 60 DEG C ± 0.5 DEG C immediately, remove polybag, insulation 24h;

Four, first group and second group of sample all being immersed temperature is 2h in the Water Tank with Temp.-controlled of 25 DEG C ± 0.5 DEG C;

Five, take out sample immediately by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0716-1993 test method, carry out diametral compression test by the loading speed of 50mm/min, obtain the peak load P tested;

Six, the cleavage strength of 2 groups of samples is obtained respectively by following formula:

${\mathrm{\σ}}_1=\frac{2P_1}{\mathrm{\π}{h}_1{D}_1}$

${\mathrm{\σ}}_2=\frac{2P_2}{\mathrm{\π}{h}_2{D}_2}$

In formula, σ ₁for not carrying out the cleavage strength of first group of sample of Frozen-thawed cycled, MPa; P ₁be the maximal value of the trial load of first group of sample, MPa; h ₁be the height of first group of sample, mm; D ₁be the diameter of first group of sample, mm.σ ₂for standing the cleavage strength of second group of sample of Frozen-thawed cycled, MPa; P ₂be the maximal value of the trial load of second group of sample, MPa; h ₂be the height of second group of sample, mm; D ₂be the diameter of second group of sample, mm;

Seven, freeze-thaw split strength ratio is obtained test findings is in table 3, and test findings shows, in construction coarse aggregate crushed after, after compound stands Frozen-thawed cycled, cleavage strength reduces 25.5%, larger on the impact that the water of compound is stable after crushing coarse aggregates is described.

Embodiment 4, asphalt mixture after crushing coarse aggregates cryogenic property is tested

One, in certain identical with example 1 highway, surface layer have employed AC-20C type asphalt, the crush values of ls coarse aggregate is 24%, the content of flat-elongated particles is 16%, all meet " standard specification for construction and acceptance of highway asphalt pavement " (JTGF40-2004) and show 4.8.2 to coarse aggregate quality technology used for asphalt mixture requirement, close to the upper limit of allowed band;

Two, at the construction field (site), 6 cores are randomly drawed, press the diameter of " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0705-2000 determination of test method core, height and bulk specific gravity, test findings is in table 3, then, by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0716-1993 test method, test temperature is-10 DEG C ± 0.5 DEG C, carry out diametral compression test by the loading speed of 1mm/min, obtain the cleavage strength R of sample _t1, test findings is in table 4;

Three, same batch, compound of the same type with working-yard is extracted from batching plant, after being heated to on-the-spot paving material in an oven, by the average of on-the-spot core relative density, with shaping 6 test specimens of rotary compactor, after ambient temperatare puts 2h, get core and cut into the right cylinder test specimen with on-the-spot core equidimension, by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ052-2000) T0716-1993 test method, test temperature is-10 DEG C ± 0.5 DEG C, carry out diametral compression test by the loading speed of 1mm/min, obtain the cleavage strength R of sample _t2;

Four, on-the-spot and indoor Ratio of split strength is tried to achieve test findings is in table 4, and test findings shows, in construction coarse aggregate crushed after, the cleavage strength of compound-10 DEG C reduces 22.8%, illustrates and produces obviously impact to compound crack resistance at low-temperature after crushing coarse aggregates.

Table 1 crushing coarse aggregates forward and backward mixing mineral aggregate key sieve percent of pass testing result (%)

P max	97.6	P 4.75	31.5	P 2.36	26.1	P 0.075	5.1
								P′ max	99.8	P′ 4.75	38.2	P′ 2.36	30.2	P′ 0.075	5.2
K max	102.3	K 4.75	121.3	K 2.36	115.7	K 0.075	102.0

The Marshall stability test result of table 2 scene and indoor core 60 DEG C

Table 3 on-the-spot core indirect tensile test on frozen-thaw result

The diametral compression test result of table 4 scene and indoor core-10 DEG C

Claims (1)

1. the method for testing of an asphalt mixture after crushing coarse aggregates high-temperature behavior otherness, comprise the following steps: one, 6 complete right cylinder cores that pave and roll are randomly drawed from asphalt pavement construction scene, first, press " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0705-2000 determination of test method diameter of core, height and bulk specific gravity, then, by " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0709-2000 determination of test method core 60 DEG C of Marshall stability MS, two, extract and same batch of working-yard from batching plant, compound of the same type, after being heated to on-the-spot paving material in an oven, by the average of on-the-spot sample relative density, with shaping 6 test specimens of rotary compactor, after ambient temperatare puts 2h, get core and cut into the right cylinder test specimen with on-the-spot core equidimension, press " highway engineering pitch and Asphalt Mixture Experiment code " (JTJ 052-2000) T0709-2000 determination of test method core 60 DEG C of Marshall stability MS ', three, on-the-spot and indoor Marshall stability ratio is tried to achieve

Described from asphalt pavement construction scene randomly draw 6 complete right cylinder cores that pave and roll, for extracting from cutting optimal, middle surface layer or upper layer.