Effective Thickness of Bedding Sand Layer for Shell Groove-Underside Shaped Concrete Blocks for Pavement

Underside Shaped Concrete Block (USCB) is a groove shaped block on the underside surface. The USCB concept utilizes groove pattern to grip and produce better resistance to the underside surface of block units onto the bedding sand layer. However, the horizontal movement of block units is the major problem in pavement due to vehicle braking and accelerated action. This paper presents the laboratory evaluation on vertical and horizontal displacement of shell groove-USCB pavement laid onto different bedding sand layer thickness. The bedding sand layer thickness an essential parameter to produce better USCB’s performance. A series of laboratory scale test were conducted to study USCB type of the ShellRectangular 15 mm (Shell-R15) laid on three different loose bedding sand layer thicknesses of 50 mm, 70 mm and 90 mm respectively. Then, push-in loading test and horizontal loading test were performed. The result indicates, the bedding sand layer thickness has significant influence to the vertical and horizontal displacement to USCB Shell-R15 compared to control of 50 mm loose bedding sand layer thickness. The loose bedding sand layer thickness of 70 mm performed better compared to others.