The Falling Weight Deflectometer is a device that is used to evaluate pavement and pavement layer stiffness. It is a trailer-mounted device that operates by dropping a weight on to the pavement and measuring the resulting pavement deflections.

What is a traffic speed Deflectometer?

The Traffic Speed Deflectometer (TSD), is an innovative Rolling Wheel Deflectometer measuring pavement response to applied load. ... The Greenwood TSD provides continuous bearing capacity results at project and network level while following the flow of traffic. This makes the Greenwood TSD highly cost-effective.

What is a light weight Deflectometer?

The Light-Weight Deflectometer (LWD) is a light weight portable tool used for measuring the bearing capacity (deflection) of subgrade/subsoils and unbound base layers, granular layers and backfilling materials. The zone of influence for the test typically extends to between 1 and 1.5 times the plate diameter.

What is a heavy weight Deflectometer?

The Dynatest Heavy Weight Deflectometer (HWD) is designed to impart a load pulse to the pavement surface, simulating the load produced by an aircraft. Deflection sensors, mounted around the load plate measure the deformation of the pavement in response to the load.

What does FWD measure?

The Falling Weight Deflectometer (FWD) measures the pavement surface deflection at various distances from the load. The result is a deflection bowl. This deflection bowl has been used by clients to predict the life of the recently constructed or rehabilitated pavement.

Light Weight Deflectometer LWD ASTM E2835-11 for Compaction Control from Zorn Instruments

44 related questions found

What is a Deflectometer used for?

The Falling Weight Deflectometer is a device that is used to evaluate pavement and pavement layer stiffness. It is a trailer-mounted device that operates by dropping a weight on to the pavement and measuring the resulting pavement deflections.

What is the purpose of FWD?

FWD means that the power from the engine is delivered to the front wheels of your vehicle. With FWD, the front wheels are pulling the car and The rear wheels don't receive any power on their own. The pros of a FWD vehicle are that they typically gets better fuel economy and emits less carbon dioxide.

What is the function of falling weight Deflectometer?

A falling weight deflectometer (FWD) is a testing device used by civil engineers to evaluate the physical properties of pavement in highways, local roads, airport pavements, harbor areas, railway tracks and elsewhere.

How does Benkelman beam determine rebound deflection?

Measurement Process

With the Benkelman Beam measurement method, the vertical deflection of the road surface is measured after a defined load of 5 tons has rolled away. ... The dial gauge is set to zero before the measurement begins. The load vehicle moves away and the pavement surface rebound is read from the dial gauge.

Which of the pavement have a high flexural strength?

⇒ Rigid pavements have high flexural rigidity of the concrete slab. These pavements deflect very little under loading. This is because of high modulus of elasticity of their surface course.

How plate load test is conducted?

The plate load test, which is used to determine bearing capacity and settlement, may be carried out by either using a gravity loading or truss loading method. A test pit of the same depth as the foundation and width equal to five times the size of bearing plate is dug in the ground.

What is TSD data?

The ARRB Traffic Speed Deflectometer (TSD) uses seven Doppler lasers to monitor the response of a pavement to the application of a mass at highway speeds. The data collected provides continuous pavement deflection profiles, from which bearing capacity indices can be derived and pavement fatigue can be estimated.

What is Benkelman beam deflection?

Benkelman Beam is a simple lever-arm device that measures the deflection of flexible pavements under the action of moving wheel loads. ... Deflections measured on a dial indicator are doubled to obtain total pavement deflection.

What is rebound deflection?

Rebound Deflection is defined as the amount of vertical rebound deflection of a pavement surface due to the moving load (Bina Marga, 2005).

Which IRC code is referred to while performing the Benkelman beam deflection studies?

Explanation: IRC 81:1997 is used to refer to while conducting the BBD test. It gives the guidelines for the strengthening of flexible road pavements using the BBD studies.

What is back calculation in FWD?

Backcalculation takes a measured surface deflection and attempts to match it (to within some tolerable error) with a calculated surface deflection generated from an identical pavement structure using assumed layer stiffnesses (moduli).

What is BBD test?

BBD test are widely used as a tool for structural evaluation. Benkelman Beam Deflection studies are one of the non-destructive techniques for the structural evaluation of flexible pavements. ... This is the basic principle of the deflection method of pavement evaluation.

What is a Deflectograph survey?

Deflectograph surveys assess the structural condition of pavements by measuring the transient deflection of the road surface under the action of a rolling wheel at standard loading conditions. ... This method of operation gives measurements of deflection in both wheel paths at about 4 metre intervals.

Does FWD work in snow?

FWD is vastly better in the snow than a rear-wheel-drive car. ... The bottom line: FWD is a good choice for the average driver who uses his vehicle to get from “a” to “b” and would like to have decent traction on those few days each winter when there's some snow on the roads.

Is my car AWD or FWD?

Look underneath your vehicle while it is turned off for the axle shaft. The shaft simply looks like a large bar going from the front to rear axle. If you see an axle shaft running from the front to rear axles, you have an all-wheel drive vehicle.

Whats better FWD or RWD?

Most of the time, front-wheel drive cars get better gas mileage because the weight of the drivetrain is less than that of a rear-wheel vehicle. FWD vehicles also get better traction because the weight of the engine and transmission are over the front wheels. ... Front-wheel drive vehicles may also feature all-wheel drive.

What are the factors which affects pavement design?

There are many factors that affect pavement design which can be classified into four categories as traffic and loading, structural models, material characterization, environment.

What is Benkelman beam test and its necessity?

The Benkelman beam was developed at the WASHO Road Test for the purpose of measur- ing the deflection of a flexible pavement under a loaded pneumatic tire. The beam fulfilled a need for a simple instrument that could quickly and conveniently measure the pavement sur- face deflection at any point.

What is beam deflection?

Deflection, in structural engineering terms, means the movement of a beam or node from its original position. It happens due to the forces and loads being applied to the body. Deflection also referred to as displacement, which can occur from externally applied loads or from the weight of the body structure itself.

What is the layer that is not required in cement road?

The layer not required in cement road is

The base course may be required but in cement road it is not mandatory, it is better if it is provided.