Characterization of pervious concrete with blended natural aggregate and recycled concrete aggregates

The utilization of recycled coarse aggregates (RCA) from construction and demolition wastes to produce green concrete serves as a sustainable solution with manifold environmental benefits. This study aims to widen the potential uses of RCA to fabricate pervious concrete for non-structural applications. The mechanical and surface properties, permeability, and greenhouse gases assessment of pervious concrete made with blended normal granite aggregates and RCA were investigated in this work. RCA replacement levels of 20%, 40%, 60%, 80% and 100% were used. Experimental results show that the RCA mixes have lower mechanical properties. Microscopic analyses show that the lower strength of RCA mixes was attributed to the failure path of RCA specimens which occurred at the weaker adhered mortar on RCA. Despite the drop in strength, all RCA-mixes attained the minimum BS EN 1338 requirements in terms of skid and abrasion resistance. In the mix with 100% RCA, the waste content in the pervious concrete mix was 87% by weight and 73% by volume. The greenhouse gases assessment also shows that the CO2 emission of this 100% RCA mix is 24% lower than the control mix

Hydraulic and strength characteristics of pervious concrete containing a high volume of construction and demolition waste as aggregates

Recently, construction and demolition waste generated in Malaysia has dramatically increased. For long-term sustainable development, demolition wastes can be recycled in concrete production. Recycled concrete aggregate (RCA) was successfully used in our previous study as coarse aggregate replacement. This research aims to explore the production of a greener RCA-based pervious concrete by using recycled fine aggregates (RFA). The percentage of waste in the concrete will be 72% by volume of the total concrete mixture constituents. The mixture design is based on a targeted porosity of 15% at the water to cement (w/c) ratios of 0.30, 0.35, and 0.40. Furthermore, the effects of 10% (weight of coarse aggregate) river sand and RFA on the mechanical properties and hydraulic conductivity were compared. The experimental results revealed that 0.35 w/c produced the best mechanical properties. However, the w/c ratio had no effect on the hydraulic properties of the concrete. In addition, incorporating RFA into the concrete improved its mechanical properties, where the compressive and splitting tensile strength of the concrete improved by 7% and 37% respectively. Comparing between RFA and river sand, microscopic analyses showed that the adhered mortar on RFA reduced its crack diversion ability in enhancing the pervious concrete’s strength.No sponso