Use of local geomaterials for water harvesting in Jordan

A 5 year project was conducted to develop alkali activated cements form Jordanian local resources. The main use of these materials in this project was for making water ponds for agriculture use. An important issue was developing low energy impact materials that can be produced on site with limited tools that can be locally bought. In the first stage a selection of raw materials has been made. Some Jordanian kaolinitic soils (containing 65% kaolinite) can be activated with strong alkaline solutions (NaOH or KOH based). The composition and cure procedure was optimized.
As the optimal amount of water is close to the plastic limit of the kaolinite a special mixer with horizontal shaft was designed. The best mixing was obtained when first mixing the sand or filler with the liquid and then adding the clay. Tiles were pressed in a press used for cement tiles.
The stones were cured at 45°C in large furnace for 21 days. In the field this furnace could be replace by a green house. A pond was created with these tiles. The mortar used to place the tiles and to fill the joints between the tiles, is a geopolymer consisting of metakaolinite and sodiumsilicate solution. The reason for switching to metakaolinite is that filling the joints with the plastic unheated clay was not possible. The metakaolinite based geopolymer has lost the plasticity and can be poured and used as a mortar.