Falling Weight Deflectometer

FWD PRIMAX — Falling Weight Deflectometer

The FWD PRIMAX is a van-integrated Falling Weight Deflectometer (FWD) used for non-destructive structural evaluation of flexible and rigid pavements, airport runways, and railway subgrades. A calibrated falling weight delivers an impulse load to the pavement surface via a load plate, and a series of geophones measures the resulting deflection bowl. The data is analysed to back-calculate layer moduli and estimate remaining pavement life.

JS Civil Lab Solutions supplies the FWD PRIMAX for NHAI highway concession projects, airport pavement management, and structural overlay design across India.

Key Features

• Load range: 7–250 kN (adjustable drop height and mass)
• Geophone array: 9 sensors at standard spacings (0, 200, 300, 450, 600, 900, 1200, 1500, 1800 mm)
• Load pulse duration: 25–30 ms (replicates heavy truck axle load)
• Integrated temperature sensors: pavement surface and air
• Van-mounted: full test cycle (position, drop, record) in under 2 minutes
• Software: ELMOD / MODULUS for back-calculation; exports to AASHTO design format
• Standards: ASTM D4694, ASTM D4695, EN 12697-29

Applications

Pavement structural condition surveys for overlay design, remaining life prediction, maintenance priority ranking, and construction quality control. Mandatory on NHAI expressway projects and airport pavement maintenance programmes (AAI).

Enquire

Contact JS Civil Lab Solutions at +91 93596 24761 for specifications, demo, and project-based pricing. Rental and survey service options available.