Correlating Laboratory and Field Compaction Levels to Achieve Optimum In Situ Mechanical Properties for Pervious Concrete Pavements

Mechanical properties of pervious concrete (PC) are highly influenced by the applied compaction; however, the required level of compaction to achieve the desired density and strength in the field is currently unknown. In some cases, compaction is established empirically on costly test panels. In this study, the relationship between the applied compaction force and the hardened porosity ($Ø$) and compressive strength ($f_c$) was investigated. Three PC mix proportions with varying paste contents were compacted in the laboratory using a lightweight deflectometer (LWD) at four different compaction levels. Porosity and 7-day $f_c$ testing were carried out on cylinders cast with each compaction level. In general, the first 15 LWD drops influenced $Ø$ and $f_c$ significantly, while the effect of compaction beyond that level was less significant. The applied compaction force recorded by the LWD was used to obtain the required properties of a rotary roller-screed to apply an equivalent compaction force in the field. Then, regression-based models were developed to estimate the 7-day $Ø$ and $f_c$ of PC based on the applied compaction force and the paste content. The developed models provide a practical solution to compute the required compaction force in the field to achieve the desired PC mechanical properties.