Improvement of subgrade soil by blending tyre driven aggregate (TDA)

Pavements are largely affected by the inherent variability of soil nature which may be change in type and condition. Subgrade soils are characterized by their resistance to deformation under load, which can be measured in terms of strength and stiffness. The subgrade strength of soil is the key factor to ensure the sustainability of the pavement and is considered as of prime importance for design of pavement. If pavements are constructed on weak subgrade soils, then there are chances of possible settlement and subsequent pavement failure. The aim of study is to improve the bearing pressure of existing subgrade soil using tyre driven aggregates obtained from scrap tyre. The California Bearing Ratio (CBR) tests were performed on existing subgrade soil and the improved soil with 5%, 15%, and 30% replacement of tyre driven aggregates. The maximum dry density of soil was found to be 1636 kg/m3 at optimum moisture content of 21.26%. The CBR of the existing ground was measured as 3.90%. It was revealed that CBR value was improved by 5.1%, 10% and 28.7% of existing value when subgrade grade soil was replaced by 5%, 15% and at 30% demolished aggregates, respectively

A Comparison between the Empirical and Mechanistic-Empirical Pavement Design Methods

In this paper a comparative study has been carried out between the Mechanistic-Empirical Pavement Design Methods and the Empirical Pavement Design Methods. For the purpose of this paper, nine pavement design sections have been prepared using the Mechanistic-Empirical Methods represented by the Asphalt Institute Design Method (SW-1 software of the Asphalt Institute) and the Empirical Design represented by AASHTO 1993 and TRL Road Note No.31, using the same traffic loading and subgrade strength. Three traffic loading scenarios have been considered for this study. (Key words: Mechanistic-Empirical, Empirical, axle loads, Subgrade Strength, pavement design)

Analisis Lalu Lintas pada Ruas Jalan Lingkar Sicincin-Lubuk Alung Kab.Padang Pariaman untuk Disain Perkerasan

Traffic is an important part of road pavement design in addition to subgrade strength. This is because traffic is a burden for the road and is very decisive in the thick planning of each layer of pavement. Thus the calculation of the traffic load should have been carried out before carrying out the design of the pavement. The Sicincin - Lubuk Alung ring road section located in Kab.Padang Pariaman is one of the road sections designed with pavement design. Therefore, a traffic survey was carried out on the road section. Traffic surveys are carried out for three days, two days on weekdays and one day on holidays. Every day the survey time is divided into three times, morning, afternoon and evening at rush hour. The survey in the morning takes place at 07:15 - 08:15 and 08:15 - 09:15 while in the afternoon it takes place at 13:00 - 14:00 and 14:00 - 15:00. Furthermore, for the afternoon survey, it will be held at 16:00 - 17:00 and 17:00 - 18:00. After processing the data, in each survey period the LHR value is obtained for both directions. The LHR value used for pavement design is the largest LHR value of all LHR values obtained.