EXPERIMENTAL EVALUATION OF PERVIOUS CONCRETE DESIGNED BASED ON THE EXCESS PASTE THEORY: STRENGTH AND WATER PERMEABILITY

Urbanization increases impervious areas, requiring sustainable stormwater management like pervious concrete (PC). Standardized PC design methods are limited in Vietnam. This study evaluated the Excess Paste Theory, based on coating aggregates without filling voids to maintain permeability, for designing PC for pedestrian areas targeting ~40% void ratio and 7.5-10 MPa compressive strength. Experimental samples exhibited high interconnected porosity and efficient drainage. Average 7-day compressive strength was 8.5 MPa, meeting the target pedestrian traffic area. Variability was noted (manual mixing, lack of equipemnt for vibration and compaction of 10kPa for concrete), with failure in the cement paste layer. Initial results indicate the method's potential. Future work should enhance paste strength (e.g., via fine aggregate and/or reduced Dmax) for uniformity. PC design requires balancing porosity and strength