A Study On Mix Proportions Design And Performance Of Porous Concrete

The porous concrete is a kind of environmentally-friendly concretewith continuous porosity mixed with special technology. It has certainintensity and permeability of air and water. In this study, the mixproportions design and performance of porous concrete were investingatedexperimentally. The conclusions can be drawn investigation as follows:1. Volume method is adopted in the design of proportion of mixture andthe method is reasonable, which is identified by experiments.2. The mix proportions, preparation, strength and permeability of porousconcrete were investigated. On this basis an optimal mixture wereobtained to matching with 25 MPa compressive strength, 4 MPaflexural strength and 1 mm/s permeability coefficient. The optimalmixture is with the water to cement ratio of 0.20 or 0.25, goal porosityof 15%, casting only once, vibrating.3. Testing with self-designed permeability apparatus, the relationshipbetween permeability coefficient K and porosity P were obtained andthe fitting equations were K_7d=0.179P^1.427 K_28d=0.138P^1.5154. On the base of experiment, the paper discusses and analyzes the mainfactor in strength and permeability. The fitting equations were 5. The test pavement shows that the excellent permeability of porousconcrete and its well effect of improving "Urban Heat IslandEffects".