Analysis of factors affecting costs of pavement in-place recycling

Abstract

All of pavement rehabilitation projects with pavement in-place recycing of DOH & DOR will be operated by employing contractors. The total cost for employing can be calculated from the standard estimaton of road. Since DOH&DOR use a formula that comes from many factors and variables for estimating direct costs of pavement in-lace recycling, it has a problem that what different between total cost estimation of DOH & DOR, and total cost estmation of the contractor is. The objectives of this research are to analyze factors and variables affecting total cost of pavement in-place recycling of DOH & DOR and to analyze factors and variables affecting costs & profit of pavement in-place recycling of the contractor. The study aims to find some guidelines for improving total cost estimation of DOH & DOR. From analysis of total cost structure, we find that total cost of DOH & DOR can be divided into direct costs and operation costs that consist of 22 costs. The total cost of the contractor can be divided into direct costs and indirect costs that consist of 26 costs. By identifying costs in total cost of DOH & DOR, and costs in total cost of the contractor into group of costs that consists of materials costs, labor and machine costs, operation costs, profit, and TAX, it can find that the labor and machine costs of DOH & DOR is higher than the contractor. The cost that are significantly caused of difference are investment cost, maintenance costs and depreciation. The difference in defining factors such as type, number, prices, and salvage value of machines is the major factors affecting these costs. From the analysis of factors affecting costs of pavement in-place recycling, we can find some guidelines for improving total cost estimation of DOH & DOR in 3 ways that comprise of 1) Materials costs estimation improvement by using percentage of cement from field test instead of using from the tables. 2) Labor and machine costs estimation improvement by using update new machine prices from sale agencies for calculating investment cost, maintenance cost and depreciation cost. In addition, the cement truck and water truck may be not included in total cost estimation. 3) Operation costs estimation improvement by using Factor F in case normal rain for project that is operated out of rainy season even though this area is located in rainy area.