The Automatic Asphalt Mixture Core Drilling Machine is a specialized laboratory and field testing device designed for preparing cylindrical core specimens from asphalt mixtures and pavement structures. With automated control, stable drilling performance, and high-precision operation, it helps improve the efficiency and consistency of specimen preparation for asphalt performance evaluation. This article introduces the machine’s technical parameters and functions, installation and commissioning, preparation before operation, detailed operating procedures, common troubleshooting methods, and essential safety precautions to ensure reliable and safe use.

I.Asphalt Mixture Core Drilling Machines Technical Parameters and Functions

(I) Core Function Parameters

1. Supported Core Sample Sizes

Diameter × Height: 100mm × 180mm, 50mm × 180mm, 38mm × 180mm, 125mm × 100mm (Custom sizes available)

2. Axial Core Taking Fixture Specimen Sizes

Standard Blocks: 300mm × 300mm, 450mm × 150mm × 180mm; Cylindrical: Φ100mm × 180mm, Φ150mm × 180mm

3. Specimen Moving Platform

Dual-Axis Tracks (X/Y Axis):

<br>X-axis: 0-150mm (accuracy ±0.1mm)

<br>Y-axis: 0-250mm (accuracy ±0.1mm)

<br>Supports manual knob fine-tuning and automatic programming (touchscreen preset coordinates)

4. Drill Bit Rotation Speed

Infinitely variable speed (default 650 rpm, adjustable as needed)

5. Core Feed Speed

0-150 mm/min (Adjustable, suitable for asphalt mixtures of different hardness)

6. Core Perpendicularity Error

≤1% (Ensuring accuracy through high-strength alloy guide sleeves and precision bearings)

7. Automation Level

Fully automatic control (integrated process of "drill bit start → platform positioning → feed coring → retraction and shutdown", supports one-button start/emergency stop)

8. Wastewater Filtration Treatment

Integrated circulating filtration system:<br>Filtration accuracy ≤50μm<br>Process: Wastewater diversion channel → primary screen (intercepts large particles) → precision filter element → clean water tank for reuse, environmentally friendly discharge

Reference Standards：

The machine is designed with reference to:

ASTM D5361/D5361M — Standard Practice for Sampling Compacted Asphalt Mixtures for Testing

AASHTO T 24 — Standard Method of Test for Obtaining and Testing Drilled Cores of Asphalt Mixtures

EN 12697-27 — Bituminous mixtures — Test methods — Sampling

EN 12697-29 — Bituminous mixtures — Test methods — Determination of the dimensions of a bituminous specimen

(II) Key Structure and Technical Specifications

1. Multi-Specification Compatible Design

Equipped with dedicated clamps and positioning bases, it is compatible with axial cored block specimens (300×300mm, 450×150×180mm), cylindrical specimens (Φ100×180mm, Φ150×180mm), and radial cored annular components (Φ150×100mm). The clamps ensure the specimens are stable and the cored position is accurate.

2. High-Precision Moving Platform

Drive System: The X-axis (lateral) and Y-axis (vertical) utilize servo motors, ball screw drives, and linear guides, ensuring smooth movement and a repeatability accuracy ≤0.1mm.

Operating Modes: Supports manual fine-tuning (knob control) and automatic programming (target coordinates are input via a 10-inch touchscreen, and the platform automatically moves to the designated position), adapting to the multi-area coring requirements of complex specimens.

3. Intelligent Control System

Automatic Operation Process:

The machine integrates a PLC controller to achieve fully automatic control of the entire drilling process:Drill bit start → Platform positioning → Core drilling feed → Retracting and stopping.It supports one-button start operation and dual-redundant emergency stop functions combining mechanical and electronic protection systems.

Parameter Setting:

The HMI touch screen allows users to adjust key parameters, including drill bit speed (default 650 rpm), feed speed (0–150 mm/min), target drilling depth, and other settings. This enables the machine to meet core drilling requirements for asphalt mixtures with different hardness levels.

Safety Protection:

The system is equipped with multiple safety protection functions, including overload protection (monitoring motor current), drill bit jam detection (torque feedback), and dual-redundant emergency stop buttons to ensure safe and reliable operation.

4. Perpendicularity and Precision Control

Guiding Mechanism: Utilizing a high-strength alloy guide sleeve (coaxially mounted with the drill bit) and precision bearing positioning, the drill bit is always fed perpendicularly along the specimen axis, with a perpendicularity error strictly ≤1%.

Real-time Calibration (Optional): A laser rangefinder sensor monitors the initial distance between the drill bit and the specimen surface, dynamically adjusting the feed starting point to further improve core sampling position accuracy.

5. Wastewater Filtration Treatment Device

Functional Requirements: During the core extraction process, a continuous jet of coolant (water or specialized cutting fluid) is sprayed to cool the wastewater and remove debris. The equipment integrates a circulating filtration system to prevent direct discharge of wastewater.

Technical Implementation:

<br>Filtration Process: Wastewater is collected via a guide channel → primary screen (intercepts large particles) → precision filter element (filtration accuracy 50μm, removes fine dust and asphalt particles) → clean water tank for reuse.

<br>Maintenance Design: The filter element supports quick replacement; the wastewater tank has a level alarm function to remind users to regularly clean the sediment and ensure long-term stable filtration efficiency.

II. Asphalt Mixture Core Drilling Machines Installation and Commissioning (Brief Description)

(I) Installation Environment Requirements

Ambient temperature: 5℃~40℃; Relative humidity: ≤80% (non-condensing);

Ground: Flat and firm (concrete foundation, levelness ≤3mm/m²);

Power supply: AC 380V±10% (three-phase five-wire system), power ≥5kW;

Coolant: Clean tap water or special cutting fluid (flow rate ≥5L/min).

(II) Installation Steps (User Reference)

1. Place the main unit on a flat surface and level it using the vibration-damping base (calibrate with a spirit level);

2. Connect the power cord (ensuring reliable grounding) and coolant lines;

3. Install the wastewater filtration module (connect the guide channel to the core sampling area, and connect the filter housing to the clean water tank);

4. Turn on the power, start the control system, and check if the touchscreen and motor response are normal.

(III) Commissioning (Recommended to be completed by the manufacturer's technical personnel)

Includes no-load testing (spindle rotation, platform movement), platform coordinate calibration (accuracy verification), verticality testing (standard specimen core sampling inspection), and wastewater filtration function verification, etc.

III. Asphalt Mixture Core Drilling Machines Operating Procedures (Detailed Steps)

(I) Power-On and Initialization

1. Connect the power supply and turn on the main switch to start the control system (touchscreen will light up).

2. Check the main interface of the touchscreen to confirm there are no fault alarms (such as "spindle abnormality" or "platform over-limit"); if any are present, troubleshoot and reset as prompted.

3. Manually rotate the spindle (low speed) to confirm the rotation direction is correct (usually clockwise cutting direction).

(II) Parameter Settings (Touchscreen Operation)

1. Enter the "Parameter Settings" interface and adjust the following according to the requirements of the specimen and core sample:

<br>Drill bit speed (default 650 rpm, can be reduced to 500 rpm for soft materials, and increased to 800 rpm for hard materials);

<br>Feed speed (default 30-50 mm/min, can be slightly faster for soft materials, and reduced to 10-20 mm/min for hard materials);

<br>Target core depth (e.g., 180 mm);

<br>Core sampling mode (axial/radial).

2. Set the coordinates of the specimen movement platform (X/Y axis):

<br>Enter the horizontal (X-axis) and vertical (Y-axis) coordinates of the target core sampling position (e.g., X=75 mm, Y=120 mm);

<br>Or select "Manual Mode" and fine-tune the platform position using the knobs.

(III) Specimen Fixing and Positioning

1. Place the specimen in the moving platform fixture and adjust its position so that the target core sampling point is aligned with the drill bit axis (refer to the platform scale).

2. Clamp the specimen (with moderate force to avoid deformation but ensure stability). If necessary, use a level to calibrate the specimen's levelness.

(IV) Automatic Core Retrieval Operation

1. After confirming the parameters are correct, press the "Automatic Start" button on the touchscreen. The equipment will operate according to the following process:

<br>Spindle starts (reaches the set speed) → Platform moves to the preset coordinates → Drill bit feeds for core retrieval → Automatic retraction after reaching the target depth → Drill bit returns to the initial position.

2. Observe the following during core retrieval:

<br>Whether the coolant is continuously sprayed onto the cutting area;

<br>Whether there is any abnormal vibration/noise in the equipment (press emergency stop immediately if abnormal);

<br>Whether the wastewater flows normally into the guide channel.

(V) Shutdown and Core Sample Removal

1. After core sampling is completed, the equipment will automatically stop (or you can manually press the "Stop" button).

2. Loosen the specimen clamp and remove the specimen with the core sample (or remove the core sample directly).

3. Clean the drill bit and platform debris, and check the integrity of the core sample (no severe damage/delamination).

(VI) Power Off

1. Turn off the power to the spindle and feed system (touchscreen "System Shutdown" option).

2. Disconnect the main power supply (if not in use for an extended period).

3. Clean the surface of the equipment of wastewater and debris, and record the core sampling parameters and specimen information.

IV. Asphalt Mixture Core Drilling Machines Maintenance and Care

(I) Daily Maintenance

After each use, clean the equipment surface of wastewater and drill cuttings (wipe with a soft cloth; do not use corrosive solvents); clean the sediment and residue in the wastewater filter tank.

Check drill bit wear (replace when the cutting edge nick is >1mm); confirm there are no leaks in the coolant lines.

(II) Periodic Maintenance (Monthly/Quarterly)

Replace the wastewater filter precision element (generally replace every 50-100 cycles or when the filter element differential pressure alarms, depending on usage frequency).

Lubricate the X/Y axis guides and lead screws (apply an appropriate amount of grease).

Check the spindle bearing clearance (adjust or replace if abnormal vibration occurs); calibrate the positioning accuracy of the moving platform (verify with standard gauge blocks).

(III) Long-Term Storage

Clean the equipment and apply anti-rust oil (to exposed metal parts); remove the drill bit and store it separately; empty and dry the wastewater tank.