Utilization of Six Sigma in Quality Improvement of Recycled Aggregates Concrete

Table 2

Summary of the two-level preliminary DOE design.

Levels	Impact factor
	Quality of RA aggregates	w/c	% Recycled coarse aggregate	% Recycled fine aggregate	Curing
High	1 (best)	0.5	25%	25%	RH100%
Low	2 (worst)	0.7	75%	75%	Air