CN104251799A - Interlayer friction resistance test method for water stabilized gravel layer and asphalt layer - Google Patents

Abstract

The invention relates to a test method, and especially relates to an interlayer friction resistance test method for a water stabilized gravel layer and an asphalt layer. The method comprises the following steps: carrying out mechanical calculation on an interlayer contact structure to obtain a vertical pressure press of an interlayer contact position as a test control index, and carrying out tests to detect the transverse shear stress as an interlayer connection quality control standard. The method simplifies traffic load to transverse constraining force can truly simulate the interlayer shear stress state under the action of the traffic load, standardizes the making rule, the shearing test process and the data processing process of a workpiece, provides control basis for the control of the seal construction quality, and guarantees the prolongation of the service life of a road.

Description

The interlayer friction resistance test method of a kind of water stability detritus layer and brea bed

Technical field

The present invention relates to a kind of test method, particularly the interlayer friction resistance test method of a kind of water stability detritus layer and brea bed.

Background technology

Water stability detritus, namely cement stabilized macadam makes aggregate with graded broken stone, adopts the Binder Materials of some and the space of enough grey volume of slurry filler aggregates, to pave compacting by embedded squeezing principle.Its compactness is close to packing, and intensity mainly by the embedded squeezing lock knot principle between rubble, has enough grey volume of slurry to come the space of filler aggregate simultaneously.Its early strength is high, and intensity length of time and increase and form plate body very soon, thus has higher intensity, impervious degree and frost resistance better.Cement stabilized macadam cement consumption is generally compound 3%-7%, and the unconfined compressive strength of 7 days can reach 5.0Mpa, high compared with other roadbed materials.It is not muddy that cement stabilized macadam survives rear chance rain, and surface is solid, is the desirable base material of high class pavement.

In current urban road and super expressway, the laying method that general employing water stability detritus is combined with pitch, water stability detritus layer is as basic unit, and brea bed is as surface layer, and depend on its interlayer friction resistance and shearing strength at intersection fatigue behaviour the serviceable life on this road surface, lower and not easy to operate by the method precision of its result of test acquisition at present.

In order to determine the shear stress that interlayer exists more accurately, the calculating under finite element software need be utilized to carry out different structure combination.Certainly, there is relation the size of interlaminar shear stress and temperature, thickness, interlayer present position, so want the shear stress knowing interlayer accurately, and must for conditions such as concrete textural association, temperature, materials.

Summary of the invention

In order to solve the problem of prior art, the invention provides the interlayer friction resistance test method of a kind of water stability detritus layer and brea bed, it carries out Mechanics Calculation with regard to the structure that there is interlayer contact, the compressed stress of computation layer Contact position and transverse shearing stress value size, as the control criterion of tired shear test.

The technical solution adopted in the present invention is as follows:

An interlayer friction resistance test method for water stability detritus layer and brea bed, its method specifically comprises the following steps:

A, make column shaped rotating compaction moulding test specimen according to testing regulations, kind of calliper piece lengths L, exact value 0.1mm;

B, described gyratory compaction molding test specimen is put into rotary compactor die trial, together put into baking oven be heated to 130 DEG C for subsequent use;

C, mode according to gyratory compaction molding test specimen, carry out the making of composite samples, cool for subsequent use to room temperature after the demoulding, described gyratory compaction molding test specimen and composite samples make two groups respectively;

D, one group of coupon level is placed on analyzer fixing, and adjust whole test specimen and be the level of state, whole analyzer is added test specimen and puts into temperature-controlled cabinet, be adjusted to test temperature, after temperature stabilization, place two hours;

E, measure maximum friction resistance, with the speed of 0.1mm/s, test specimen is pressurizeed, record power and displacement course in time, maximal destruction power N _maxwith relative displacement d _max;

F, utilize other one group of identical test specimen, pressurize step by step according to the stress of 0.2Nmax, 0.4Nmax, 0.6Nmax, 0.8Nmax, at every turn with after the pressurization of the speed of 0.1mm/s, hold lotus 5 seconds, then unload; Add second level load again by same steps, record each displacement di, calculate the shear stress τ of load at different levels, wherein the computing formula of shear stress τ is:

$\mathrm{\τ}=\frac{F}{S}$ Formula (1)

Wherein: the vertical load (N) that F--applies, S is that interlayer contact area calculates by formula 2

$S=2\×(\frac{\mathrm{arctg}\left(\frac{d}{2R}\right)}{2\mathrm{\π}}\×\mathrm{\π}{R}^2-\frac{\mathrm{dR}}{2}\×\cos \left(\mathrm{arctg}\left(\frac{d}{2R}\right)\right))$ Formula (2)

Wherein:

S--interlayer contact area (m ²)

D--relative floor displacement (m)

R--test specimen radius is 0.075m;

The curve map of G, drafting shear stress τ and displacement di, obtains maximum shear τ _maxwith the shift value of correspondence.

The concrete steps of described making cylinder specimen are: make diameter 6cm, the cylindrical cement stabilized macadam test specimen of high 15cm, surface sprinkling emulsification pitch penetration oil, hot radical matter tar seal oil, spreading premixed macadam immediately, by rotary compactor compacting, mark is supported seven days or three days.

The method of the making of described composite samples is specifically: use bi tumenf orr oad AC-25, dense bitumen stabilization gravel compound or LSPM, according to maximum theory density and voidage, amount used when calculating shaping described test specimen also weighs up, by rotary compactor compacting, put into baking oven and be heated to 170 DEG C.

The beneficial effect that technical scheme provided by the invention is brought is:

Traffic load is reduced to lateral confinement power by the present invention, the shear stress state of interlayer under Driving Loading can be simulated really, and standardization test specimen producton order and shear test process, data handling procedure, thering is provided control foundation for controlling sealing construction quality, providing safeguard for extending Road Service Life.

Accompanying drawing explanation

Accompanying drawing 1 is for interlayer contact areal calculation principle schematic in the interlayer friction resistance test method of a kind of water stability detritus layer of the present invention and brea bed.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly, below embodiment of the present invention is described further in detail.

Embodiment one: the test method of the present embodiment is specific as follows:

1) make the cylindrical cement stabilized macadam test specimen of 6 × 15cm according to testing regulations, permeable layers emulsified asphalt is sprayed according to field control amount in surface, and mark supports seven (or three) sky, kind of calliper piece lengths L, exact value 0.1mm;

2) according to on-the-spot working control amount, emulsification pitch penetration oil, hot radical matter tar seal oil is sprayed, spreading premixed macadam immediately, compacting;

3) cement stabilized macadam test specimen is put into rotary compactor die trial, together put into baking oven to 130 DEG C for subsequent use;

4) bi tumenf orr oad AC-25 is used, dense bitumen stabilization gravel compound or LSPM, according to maximum theory density and voidage, amount used when calculating shaping described test specimen also weighs up, by rotary compactor compacting, put into baking oven and be heated to 170 DEG C;

5) according to the mode of gyratory compaction molding test specimen, the making of composite samples is carried out, cool for subsequent use to room temperature after the demoulding, every composing type two test specimens;

6) place on analyzer by coupon level, one end screw rod is fixed, and the other end utilizes slippage baffle plate to fix, and adjusts whole test specimen and be the level of state, and degree of tightness screw rod is to the horizontal compressive stress required, being adjusted to reading is 0;

7) whole instrument is put into temperature-controlled cabinet (MTS support equipment), be adjusted to test temperature, after stable, place two hours;

8) measure maximum friction resistance, pressurize with the speed of 0.1mm/s, record power and displacement course in time, maximal destruction power Nmax and relative displacement dmax;

9) utilize other one group of identical test specimen, pressurize step by step according to the stress of 0.2Nmax, 0.4Nmax, 0.6Nmax, 0.8Nmax, at every turn with after the pressurization of the speed of 0.1mm/s, hold lotus 5s, then unload; Add second level load again by same steps, record each displacement di (or displacement curve in time), calculate shear stress τ and the shearing strain ε of load at different levels _τ, Calculation Shear formula:

$\mathrm{\τ}=\frac{F}{S}$ Formula (1)

Wherein: the vertical load (N) that F--applies, S is that interlayer contact area calculates by formula 2

$S=2\×(\frac{\mathrm{arctg}\left(\frac{d}{2R}\right)}{2\mathrm{\π}}\×\mathrm{\π}{R}^2-\frac{\mathrm{dR}}{2}\×\cos \left(\mathrm{arctg}\left(\frac{d}{2R}\right)\right))$ Formula (2)

Wherein:

S--interlayer contact area (m ²)

D--relative floor displacement (m)

R--test specimen radius is 0.075m; As shown in Figure 1;

Determine the index that interlayer contact destroys and standard:

Under the condition without lateral confinement power, shearing strength at intersection stress has a peak value, the displacement can thinking now is the index of interlayer continuous damage, and the size of shift value and the asphalt content of sealing, rubble consumption, test temperature are relevant, and specific standards is determined according to test findings.Shearing stress now namely as ultimate shearing strength, for maximum shear Con trolling index during torture test.Displacement during corresponding shear stress peak value is as the standard of fatigure failure.

10) draw the curve map of shear stress τ and displacement di, obtain maximum shear τ _maxwith the shift value of correspondence.

Interlayer the maximum shear stress τ max is according to the difference of test condition, and the value obtained is as following table 1:

Table 1

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (3)

1. an interlayer friction resistance test method for water stability detritus layer and brea bed, its method specifically comprises the following steps:

A, make column shaped rotating compaction moulding test specimen according to testing regulations, kind of calliper piece lengths L, exact value 0.1mm;

B, described gyratory compaction molding test specimen is put into rotary compactor die trial, together put into baking oven be heated to 130 DEG C for subsequent use;

C, mode according to gyratory compaction molding test specimen, carry out the making of composite samples, cool for subsequent use to room temperature after the demoulding, described gyratory compaction molding test specimen and composite samples make two groups respectively;

D, one group of coupon level is placed on analyzer fixing, and adjust whole test specimen and be the level of state, whole analyzer is added test specimen and puts into temperature-controlled cabinet, be adjusted to test temperature, after temperature stabilization, place two hours;

E, measure maximum friction resistance, with the speed of 0.1mm/s, test specimen is pressurizeed, record power and displacement course in time, maximal destruction power N _maxwith relative displacement d _max;

F, utilize other one group of identical test specimen, pressurize step by step according to the stress of 0.2Nmax, 0.4Nmax, 0.6Nmax, 0.8Nmax, at every turn with after the pressurization of the speed of 0.1mm/s, hold lotus 5 seconds, then unload; Add second level load again by same steps, record each displacement di, calculate shear stress τ and the shearing strain ε of load at different levels _τ, wherein the computing formula (1) of shear stress τ is:

$\mathrm{\τ}=\frac{F}{S}$ Formula (1)

Wherein: the vertical load (N) that F--applies, S is interlayer contact area, calculates by formula 2

$S=2\×(\frac{\mathrm{arctg}\left(\frac{d}{2R}\right)}{2\mathrm{\π}}\×\mathrm{\π}{R}^2-\frac{\mathrm{dR}}{2}\×\cos \left(\mathrm{arctg}\left(\frac{d}{2R}\right)\right))$ Formula (2)

Wherein:

S--interlayer contact area (m ²)

D--relative floor displacement (m)

R--test specimen radius is 0.075m;

The curve map of G, drafting shear stress τ and displacement di, obtains maximum shear τ _maxwith the shift value of correspondence.

2. the interlayer friction resistance test method of a kind of water stability detritus layer according to claim 1 and brea bed, it is characterized in that, the concrete steps of described making cylinder specimen are: make diameter 6cm, the cylindrical cement stabilized macadam test specimen of high 15cm, surface sprinkling emulsification pitch penetration oil, hot radical matter tar seal oil, spreading premixed macadam immediately, by rotary compactor compacting, health seven days under standard conditions.

3. the interlayer friction resistance test method of a kind of water stability detritus layer according to claim 1 and brea bed, it is characterized in that, the method of the making of described composite samples is specifically: use bi tumenf orr oad AC-25, dense bitumen stabilization gravel compound or LSPM, according to maximum theory density and voidage, amount used when calculating shaping described test specimen also weighs up, and by rotary compactor compacting, puts into baking oven and is heated to 170 DEG C.