Pervious Concrete (PC) has long been used in surface runoff management. But one of its major drawbacks is its low strength. Several industrial wastes apparently contain properties that could aid the increase in strength of PC such as coal fly ash and fine sawdust. Thus, their utilization is a possible solution that could address the low-strength issues of PC along with industrial waste disposal management. This study was conducted to investigate the laboratory and field performance of PC while incorporating coal fly ash (CFA) as partial cement replacement and fine sawdust (FSD) as internal curing agent and filler admixture. Tests were performed in accordance with American Society for Testing and Materials (ASTM) standards. In general, the test results showed that PC with CFA and FSD as additives in PC gained enough strength to be considered for field application. In-situ infiltration and strength results showed that the pavement conformed to the typical values for a functional PC pavement.

The Curve Number (CN) method has been widely used for estimating runoff from rainfall. However, some uncertainties in the method have been recognized by various researchers all over the world. One of which is the NRCS-assumed initial abstraction ratio (Ia/S) of 0.20. In this study, the Ia/S and the CN for the upper catchment area of the local watershed of the Sawaga river in Bukidnon were determined using rainfall-runoff event analysis of rainfall events with a total precipitation depth ranging from 21.50 mm to 57.90 mm. The event Ia/S values ranged from 0.0019 to 0.4603. The representative values of Ia/S and CN are 0.03 and 62.3, respectively. Evaluating the performance of both the original NRCS and the locally derived values through their direct runoff prediction, the standard error, coefficient of determination, and Nash-Sutcliffe efficiency indicated that both are good and have predicted the direct runoff satisfactorily. However, these indicators showed that the locally derived values gained higher accuracy in general. The percentage of mean bias displayed the most significant difference between the two, classifying the original NRCS-CN values as unsatisfactory while the locally adapted values as very good. These findings suggest that the CN method with certain adjustments on Ia/S and CN values is appropriate for the direct runoff estimation in the upper catchment area of the Sawaga river, Bukidnon.