Impact of unstructured factors on concrete through fuzzy models

Concrete is influenced by affecting conditions during its production and construction processes. The literature reveals that there is limited understanding about the effect of unstructured factors (i.e., construction site factors) on concrete product. Crew experience, compaction method, mixing time, curing humidity, and curing temperature were selected to quantify their impact on concrete compressive strength, fabrication cost, and production rates. Each response was measured and utilized for fuzzy modeling. A Sugeno-type fuzzy inference system (FIS) was obtained for quantifying each response. Model validation was accomplished by plotting predicted versus experimental data while sensitivity analysis used Monte Carlo simulation and Spearman's correlation coefficients. Curing temperature was identified as the most influential factor for concrete compressive strength while mixing time was identified to have the largest impact on concrete cost and production rates. All FISs can be used as supporting tools to discern desired concrete operating conditions.