The microcomputer-controlled asphalt mixture reflective crack testing system(hereinafter referred to as the reflective crack testing system)is an instrument for studying the entire development process of reflective cracks in asphalt mixtures from cracking to failure at low temperatures.It can realistically simulate the occurrence and development law of asphalt pavement and reflective cracks under the condition of periodic changes in weather temperature.

Asphalt Mixture Reflective Crack Testing System

Model:TDYZ-J

I.Product Introduction

In recent years,many new asphalt mixture design methods have resulted in mixtures with greater stiffness,thinner thickness,and stronger resistance to vehicle traffic.However,these materials are more susceptible to fatigue and reflective cracking.This instrument is designed to simulate the expansion and contraction movements at slab joints or near cracks.In actual engineering,these movements lead to reflective cracking in paved surfaces.Increasing the asphalt content significantly improves the mixture's resistance to reflective cracking;materials with poor resistance will fail within minutes.

This instrument not only makes it possible to describe the generation and development of cracks in asphalt mixtures,but also provides rapid and highly repeatable test results.The test results show strong correlation with beam bending fatigue test results and the in-situ low-temperature performance of the material.The reflective crack testing system uses standard-sized specimens(typically 150mm long,75mm wide,and 12-50mm high)as required by specifications.Specimens can be obtained directly from road cores or cut from specimens using a rotary compactor in the laboratory.The specimen is precisely bonded to two test plates using an adhesive bracket and special adhesive,and then mounted on a loading frame.During testing,the loading mechanism uses a triangular wave for continuous loading,alternating between tensile and compressive stresses on the specimen(unipolar or bipolar loading is optional)to simulate the movement of the road wear layer along with the movement of the underlying broken rigid material.The instrument automatically stops operating when the test reaches the termination condition.

II.Product Features:

1.Designed according to American ASTM standards

2.Basic control and operation are completed via touch screen,while test operations and data processing are completed via PC.。

3.Comprehensive test control functions,featuring unipolar and bipolar loading modes,and multiple flexible shutdown control settings.

4.High-efficiency low-temperature chamber design with an externally mounted centrifugal fan,ensuring rapid and uniform cooling.

5.Horizontal loading system with precision linear bearings and slides.

6.High-precision servo actuators and high-microstepping stepper motors.

7.The enclosure contains a video capture unit with a wide-angle lens,allowing you to observe cracks on a computer.

III.Technical Parameters

1.Maximum Load:20kN Resolution:0.001kN Accuracy:0.25%

2.Maximum Stroke:15mm(Non-test condition)

3.Displacement Measurement Range:0-10mm Resolution:1µm

4.Displacement sensor type:Digital dial indicator

5.Loading method:Displacement closed loop,load closed loop

6.Loading waveform:Triangular wave(unipolar/bipolar)

7.Temperature control range:-5~40℃(customization available for special requirements)

8.Temperature control accuracy:0.5℃

9.Test shutdown conditions:Displacement change under constant load;Load change under constant strain;Number of loading cycles