WP4C Test

The official name of the equipment is “WP4C Dewpoint PotentiaMeter” which is used to measure water potential (osmotic + matric) using the chilled-mirror dew point technique. WP4C computes water potential from the vapor pressure of air in equilibrium with the sample in the sealed sample chamber. The sample is equilibrated with the headspace of a sealed chamber that contains a mirror and a means of detecting condensation on the mirror. At equilibrium, the water potential of the air in the chamber is the same as the water potential of the sample.

• Measurement Range: 0 – 300 MPa
• Accuracy:
  • ±0.05 MPa: 0 – 5 MPa
  • 1%: 5 – 300 MPa
• Suction Range: 0.5 – 200 MPa
• Temperature Range: 59  – 104 ^oF (15 – 40 ^oC)
• Readings:
  • Rapid: <5 minutes
  • Precise: 10 – 15 minutes

Air-entry value, unsaturated strength parameters, dew point.

Design of geotechnical structures such as earth dam, slopes, earth-retaining structures.

• Banerjee, Aritra, Anand J. Puppala, and Laureano R. Hoyos. “Suction-controlled multistage triaxial testing on clayey silty soil.” Engineering Geology 265 (2020): 105409.
• Banerjee, Aritra, Anand J. Puppala, Prince Kumar, and Laureano R. Hoyos. “Stress-Dilatancy of Unsaturated Soil.” In Geo-Congress 2020: Geo-Systems, Sustainability, Geoenvironmental Engineering, and Unsaturated Soil Mechanics, pp. 420-429. Reston, VA: American Society of Civil Engineers, 2020.
• Banerjee, Aritra, Anand J. Puppala, Laureano R. Hoyos, William J. Likos, and Ujwalkumar D. Patil. “Resilient modulus of expansive soils at high suction using vapor pressure control.” Geotechnical Testing Journal 43, no. 3 (2020).
• Banerjee, Aritra, Ujwalkumar D. Patil, Anand J. Puppala, and Laureano R. Hoyos. “Suction-controlled repeated load triaxial test of subgrade soil at high suction states.” In Unsaturated Soils, Proceeding of Seventh International Conference on Unsaturated Soils. Hong Kong, China: HKUST, pp. 667-672. 2018.
• Banerjee, Aritra. “Response of unsaturated soils under monotonic and dynamic loading over moderate suction states.” PhD diss., 2017.