Evaluation of Stabilized Bases, Double Sand Seal, and Slurry Seal Pavement Sections in the Sultanate of Oman

Abstract

Petroleum Development Oman undertook a study in 1996 to evaluate the use of a sulfonated petroleum product (SPP) as a base/subbase stabilizer and the performance of slurry seal and double sand seal in paving applications. Eight different road sections were constructed for a total length of 23.3 km. They constituted part of Marmul-Thumrait road project where the average traffic is about 150 vehicles per day. The objective was to improve the performance of graded roads and provide a low-cost base suitable for application of a thin bituminous surfacing. All eight sections were constructed with the standard subbase and base layers specified for roads in the Sultanate of Oman. However, major exceptions were as follows: Section 1, a slurry seal surface on normal resheeted base; Section 2, a slurry seal surface on SPP-stabilized base and subbase; Section 3A, unstabilized base and subbase (control section); Section 3B, SPP-stabilized base and subbase with a slushed finish carried out during construction; Section 4A, SPP-stabilized base and subbase with a slushed finish carried out a period of time after pavement construction; Section 4B, SPP-stabilized base and subbase; Section 5, a double sand seal surface on SPP-stabilized base and subbase; Section 6, a double sand seal surface on normal resheeted base. Road sections were monitored monthly for 6 months. The evaluation program included visual assessment of the surface, riding quality, dust generation, gravel loss, rutting, and in situ strength with a dynamic cone penetrometer. There were no differences in gravel loss, dust generation, strength values, or signs of distress between the stabilized and unstabilized sections. For the paved roads, the slurry seal section with SPP-stabilized base and subbase displayed the best performance in terms of less rutting and bleeding.