A Study of Water Permeability on Porous Concrete Using Recycled Coarse Aggregates

Abstract

This paper presents the study of the leftover concrete for recycling by being an ingredient in the porous concrete instead of natural mineral aggregate tested in physical and mechanical properties by subdividing the leftover concrete and grading to 3 sizes; the rock which was left on a sieve 1/2 inches, 3/8 inches and number 4. The ingredient which was suitable for compressive strength and the water permeability of the porous concrete was determined by using cement paste 10, 15 and 20 percent capacity and the water cement ratio (W/C Ratio) of 0.30 was used for making an example cylindrical block with a diameter of 10 x 20 centimeter. The results showed that the compressive strength of recycled porous concrete depends on the stone size and the amount of cement paste. The recycled porous concrete will have compressive strength in the range of 23-95 kg/square cm. It is the result of the gaps in the coarse aggregate of rocks of the same size, including the old paste and mortar. Therefore, it has to require a large amount of coated cement paste and increased water absorption but there is a gap between the good cavity ratio in the range of 25 - 37 percent. As a result in a large value of water permeability the recycled coarse aggregate size 1/2 inch, which has the highest value equal to 0.989 cm/s, with the same amount of cement paste.