C&D Aggregates for Design Controlled Low Strenght Materials (CLSM) as Filling

memoria C 149 e presentazione orale In the past, trenches were filled with an addensed layer on the level of the public service pipe; the above layer’s filling was made with both addensed pozzolan sand and hydrated lime. In order to prevent the pavement road damage, Rome’s Town Council together with University of Rome “La Sapienza” and representatives of the main public service providers, have set up a working group aiming at revising methods of filling and quality standards of materials. By studying the solutions applied in the USA and other countries, it was decided to use low strength materials as filling, which is produced in concrete mixing plant, transported and quickly cast by means of concrete mixer. Being controlled low strength materials (CLSM) the best solution for filling, there is a chance to use C&D waste materials as aggregates, other than river and pozzolans sands (which are widely used in Rome’s road works). The Technical Office of Rome’s Town Council has recently released a code for pipes that holds into account the best practice for these materials’ performance: on one hand, they must guarantee to be enough resistant to support local traffic, but on the other, they must be easily removed in case maintenance service is needed. To evaluate this property, an experimental procedure has been defined in Road Material Laboratory of University of Rome “La Sapienza”; the test has been named Demolition Index. The following article presents the experimental study carried out with the aim of defining the composition of C&D to be applied in filling.