Evaluation of Soil, Cement and Construction and Demolition Waste (CDW) Mixtures for Use in Road Pavement Base and Sub-Base Applications

Abstract

Environmental harm caused by construction and demolition waste (CDW) can be minimized by using it as a raw material in other products used in civil construction. In Brazil, there are several studies on the use of CDW as an aggregate in asphalt paving mixtures. However, this application is limited by the excess of fine aggregates present in these waste materials. Therefore, a technical feasibility study was done to evaluate the use of soil, cement and CDW mixtures for road pavement base and sub-base applications by determining the Unconfined Compressive Strength of cylindrical specimens molded with mixtures of soil, cement and CDW, with cement in proportions of 2%, 4% and 6% by dry weight of the mixture of soil and CDW with variations of: 100% soil and 0% CDW; 75% soil and 25% CDW; and 50% soil and 50% CDW. Soils were sourced from the cities of Maringá and Mandaguaçu in the state of Parana with the following granulometric characteristics, respectively: high clay content and high fine sand distribution. The construction debris, derived from the grinding of ceramic bricks and mortar, was composed of the fraction that passed through a #10 sieve (2.0mm). The soils, the debris and their mixtures were classified by determining their physical properties, compaction properties and unconfined compressive strength. Results showed that the addition of CDW to soil and cement mixtures improves compaction characteristics and increases compressive strength.