# US 10,768,084 B2 · Accelerated pavement testing

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- Number: US 10,768,084 B2
- Document ID: US10768084B2
- Status: Granted
- Kind: B2
- Application number: 16/662,927
- Filed: 2019-10-24
- Published: 2020-02-20
- Granted: 2020-09-08
- Earliest claimed: 2016-02-26
- Assignees: Csir
- Applicants: Csir
- Inventors: Frederick Christoffel Rust; Morris De Beer
- Web page: https://patentgrep.com/patent/US10768084B2

## CPC

- G01N 3/36: generated by pneumatic or hydraulic means
- G01N 3/08: by applying steady tensile or compressive forces (G01N3/28 takes precedence)
- G01N 3/32: by applying repeated or pulsating forces
- G01N 33/42: Road-making materials (G01N33/38 takes precedence)
- E01C 19/34: Power-driven rammers or tampers {, e.g. air-hammer impacted shoes for ramming stone-sett paving; Hand-actuated ramming or tamping machines, e.g. tampers with manually hoisted dropping weight}
- G01N 2203/0048: Hydraulic means
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- E01C: CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR (forming roads or like surfaces by compacting or grading snow or ice E01H)

## Abstract

A method of testing pavement includes repeatedly simulating wheel loading on the pavement by repeatedly applying a plurality of discrete forces with a downwards component, in series and one after the other, to an upper surface of a test strip of the pavement thereby to simulate a load exerted by a travelling wheel and hence subjecting the pavement to accelerated testing. The discrete forces are provided by repeatedly actuating a series of actuators, one after the other, each to exert a force with a downwards component to the upper surface of the test strip of pavement, or to a portion thereof.

## Claims

### Claim 1

An accelerated pavement testing device which comprises
a carrier; and
an array of at least five actuators carried by the carrier, wherein each actuator is configured to repeatedly apply a discrete force with a downwards component to an upper surface of a test strip of pavement, each actuator being associated with at least one force transfer element or sole configured in use to transfer said discrete force from the actuator to pavement being tested, and the actuators in the array being configured repeatedly to be actuated one actuator after the other actuator in series thereby to simulate a load exerted by a travelling wheel to said test strip of pavement and hence over time to subject the pavement to accelerated testing.

### Claim 2 (depends on 1)

The accelerated pavement testing device of claim 1, in which the array of actuators is a linear array of at least fifteen actuators.

### Claim 3 (depends on 1)

The accelerated pavement testing device of claim 1, in which the actuators are arranged, when the carrier is horizontal, to apply vertically downward forces.

### Claim 4 (depends on 1)

The accelerated pavement testing device of claim 1, which comprises a force transfer member between an actuator and its associated force transfer element or sole, the force transfer member being configured to transfer force from the actuator to its associated at least one force transfer element, and the force transfer member being at an angle to an axis of movement of its associated actuator.

### Claim 5 (depends on 1)

The accelerated pavement testing device of claim 1, which comprises a frame or chassis supporting or carrying the carrier, the carrier being vertically adjustable relative to the frame or chassis.

### Claim 6 (depends on 1)

The accelerated pavement testing device of claim 1, which comprises a programmable controller to control the application of the discreet forces by the actuators, the processor being programmable to adjust one or more of:
the magnitudes of the discrete forces applied to the upper surface of the pavement to simulate and test the effect of different wheel loads;
the frequency at which the discrete forces are applied to the upper surface of the pavement to simulate and test the effect of different wheel speeds;
the magnitude of the discrete forces applied to the upper surface of the pavement by one or more actuators compared to other actuators, so that the force(s) applied by said one or more actuators differs from the force(s) applied by other actuators to simulate and test the effect of dynamic loading on the pavement;
the magnitude of the discreet forces applied to the upper surface of the pavement during a test period compared to the magnitude of the discrete forces applied to the upper surface of the pavement during another test period to simulate and test the effect of dynamic loading on the pavement;
the sequence in which the discrete forces are applied to the upper surface of the pavement to simulate and test the effect of wheels carried on multiple axles on the pavement;
and a period between the application of said discrete forces simulating wheel loading, whether wheel loading from a single axis or from or multiple axis is simulated, to simulate and test the effect of rest periods between wheel travel on the pavement.

### Claim 7 (depends on 1)

The accelerated pavement testing device of claim 1, in which each actuator is configured to apply a discrete force with a downwards component that has a magnitude of between 5 kN and 100 kN and at a frequency of between 0.5 Hz and 30 Hz.

### Claim 8 (depends on 1)

The accelerated pavement testing device of claim 1, which comprises a frame or chassis supporting or carrying the carrier, the carrier being adjustable in a plane parallel to a plane in which the frame or chassis is positioned.

### Claim 9 (depends on 1)

The accelerated pavement testing device of claim 1, in which a spacing between a majority of adjacent force transfer elements or soles in the array of actuators is between 1 mm and 10 mm.

### Claim 10 (depends on 1)

The accelerated pavement testing device of claim 1, in which the force transfer elements or soles are rectangular in outline to simulate a vehicle tyre footprint.

### Claim 11 (depends on 10)

The accelerated pavement testing device of claim 10, in which the force transfer elements or soles have a length between 150 mm and 400 mm and/or a width between 100 mm and 300 mm.