INNOVATING IMPERMEABLE CONCRETE APPROPRIATE FOR CANAL LINING USING A SPECIFIC MIXING RATIO AND APPLYING IT TO A PILOT REACH

Abstract

This research was initiated with the objective of innovating impermeable concrete appropriate for canal lining (i.e. to improve their function, as they lose water through evaporation, seepage and leakage) using a specific mixing ratio (i.e. adapting additives employed for linings). A new mixture (i.e. consisting of mortar, limestone powder and a chemical engineering admixture "EN-1 RBS", mainly defined as a permeability reducing admixture) was proposed to be investigated. Moreover; it was applied to a pilot reach and its effect was examined. Different concrete and mortar mixes with/without admixture were designed and were experimentally investigated to examine the effect of EN-1 on the characteristics of both concrete and mortar mixes as well as their permeability. The examined water content ratios (w/c) were 0.45 and 0.60. EN-1 with different concentrations was also evaluated. The results proved that the permeability/microstructure of EN-1 mixes, as well as its long-term performance, was satisfactorily improved. The piezometer readings, behind the lining with EN-1, were less than that of ordinary lining which indicated the capability of EN-1 in reducing water losses. The difference in the coefficient of permeability reached 61.50% and 81% for the field and laboratory tested, respectively. For the concrete mix with w/c of 0.60, the reduction obtained in the ISAT results was in the range of 38% to 71%, using different EN-1 concentrations. Furthermore, under certain circumstances, the tensile properties, of the new mix for both concrete and mortar (with EN-1 admixture), were enhanced.