Performance of sand-emulsion mixes under the effect of field and laboratory environmental conditions

Because of its high availability, sand is one of the most important construction materials in Egypt. The main objective of this paper is to study the performance of sand-emulsion mixes under the effect of field and laboratory environmental conditions. Laboratory simulation of environmental conditions could be achieved by subjecting sand-emulsion specimens to wet-dry cycles through immersing in water or hot-dry cycles at three high temperatures using laboratory ovens. Weight of each specimen is recorded after each cycle, and after five wet-dry/hot-dry cycles, Marshall stability and flow were determined. The effect of field environmental conditions were studied by leaving two large slabs of sand-emulsion mixes in the field for 18 months. The slabs were prepared and compacted in the field. To investigate the ability of sand-emulsion mixes to act as surface layers in low traffic volume roads, slabs were subjected to light traffic loads. Periodic surface friction evaluation was conducted using the British Pendulum Tester. After 18 months, five cores were extracted from each slab and tested for their Marshall stability and flow. The results of laboratory and field investigations supported that sand-emulsion mixes could perform well as base layers of roads under environmental conditions. In addition and based on Marshall design criteria and friction values, sand-emulsion mixes may be used as surface layers in minor/temporary roads of low to medium traffic volumes. Coarse sands could be used successfully in case of water existence and/or in high temperature regions.