Evaluation of engineering performance, carbon dioxide emission and cost analysis of pervious concrete composed of biochar and lightweight expanded clay aggregate

This work describes the effect of biochar (BC) and lightweight expanded clay aggregate (LECA) on the engineering properties (compressive strength, density, porosity, water permeability and sound absorption), CO 2 emission and cost analysis of pervious concrete. 1-50 wt% of biochar was used as a filler and 25-100 wt% LECA was used as a coarse aggregate. Moreover, the porosity values determined by the traditional method and a method using an air pycnometer were compared. The results indicated that the strength, density and sound absorption coefficient of the pervious concrete increased with increasing biochar contents up to 10 wt%, but decreased with increasing LECA contents. The porous nature of the LECA was responsible for the increased porosity and water permeability. A comparison of the porosity test methods for these materials showed that the air pycnometer method was fast and effective for samples of density