Experimental investigation of flexural behaviour of U-shaped concrete subgrade panel

In pavement design, subgrade condition is one of the criteria to be looked into. Poor subgrade made up of problematic soils could cause the soils to move upwards, known as heaving condition. The U-shaped subgrade concrete panel (USSP) is introduced in this study to help in reducing soil heave condition for low bearing capacity soils. This paper presents a description of the mechanical properties for the USSP flexural strength through experimental works. Flexural strength of USSP for 6 different sizes are compared with the control panel sizes of 150 × 150 × 50 mm, 300 × 300 × 50 mm and 600 × 600 × 70 mm. Modified supports of square-cross section steel blocks with the size of 45 × 45 mm were used in the 3-point flexural strength test to obtain the flexural strength of the control panel. The USSP sustained more flexural load compared to control panel ranging between 7 % to 88 %. The result of the flexural strength test shows that the introduction of the webs to USSP allows the USSP to sustain higher flexural load and induce lower modulus of rupture (MOR) compared to the control panel.