Service Road Construction Using Cement Stabilized MSW at the Karadiyana Open Dumpsite, Sri Lanka

Dumping of municipal solid waste (MSW) on low-land is a waste disposal method used by most of the municipal councils in Sri Lanka. Rapid economic development, population growth, inadequate infrastructure and land scarcity have made it necessary to introduce improvements to MSW dump sites in the country. Setting up of new dumping sites is now being discouraged due to public pressure and steps are underway to optimize the existing dump yards. In this regard, the heights of the fills will have to be increased after the locations have been completely filled up with MSW although owing to poor style of dumping and very low bearing capacity of the fill, most of these locations will not be able to accommodate any further filling up. The situation at the dump site at Karadiyana is also same. Thus, a decision has been taken to have cement stabilized service roads as access roads to this dump site. Several samples were collected along the proposed service road stretch and basic studies on them were undertaken using Proctor compaction and California bearing ratio (CBR) tests to classify and investigate their present capacities. The values obtained are far below the values stipulated by ICTAD. After the MSW samples were stabilized with different cement proportions, it was observed that compared to the CBR of unimproved MSW, the CBR of cement stabilized MSW is significantly higher and that it exceeds the minimum value specified by ICTAD.