BBD

Civil Tech provides BBD testing services which is a non-destructive testing for measurements of the strength evaluation of road surface layers, made of asphalt or pavement under a standard wheel load and tyre pressure. It is a standard process to determine the rebound deflection of pavement under static load on the rear axle of the standard truck. 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. It is a static procedure. The vertical deflection is recorded by a special measuring beam, which is mounted on a support frame that can be rotated at a ratio of 1:2.

Benkelman beam testing is a cost-effective means of testing conformance on new construction or testing short lengths of existing roads to determine areas requiring rehabilitation treatment. Pavement surface deflection measurements are the primary means of evaluating a flexible pavement structure and rigid pavement load transfer. Although other measurements can be made that reflect (to some degree) a pavement's structural condition, surface deflection is an important pavement evaluation method because the magnitude and shape of pavement deflection is a function of traffic (type and volume), pavement structural section, temperature affecting the pavement structure and moisture affecting the pavement structure.

Deflection measurements can be used in back calculation methods to determine pavement structural layer stiffness and the sub grade resilient modulus. Thus, many characteristics of a flexible pavement can be determined by measuring its deflection in response to load. Furthermore, pavement deflection measurements are non-destructive.

• Determine the Rebound deflection of pavement under standard wheel load & tyre pressure.
• Evaluation of the structural capacity of existing pavement.
• Estimation and design of Overlay for strengthening of weak pavement.
• This test is widely used for evaluation as well as for estimation and design of overlays for strengthening of any weak pavement for highways.

Specification

• The equipment is light weight and made of aluminum for easy portability and use at any test location.
• The apparatus is compact, unique and possess a telescopic design for quick set up and storage during transport to the test location.
• The beam is put in contact with the pavement under test between the tires of the vehicles.
• The measurement of the deflection is carried out when the vehicle passes over the test area.