Experimental evaluation of freeze-thaw durability of pervious concrete

The ASTM C666 procedure is the common test method used for evaluating the freeze-thaw durability of conventional concrete, and it has been adapted for evaluating the freeze-thaw resistance of pervious concrete; however, it is argued the test method does not represent the field conditions of neither conventional nor pervious concrete. This study mainly focused on an experimental program to evaluate the freeze-thaw durability of pervious concrete specimens using the JC446-91 test method, which measures the change in compressive strength and mass after exposure to freeze-thaw cycles, as an alternative for ASTM C666. Various parameters affecting the freeze-thaw durability of pervious concrete, namely water to cement ratio (W/C), air entrainment, inclusion of sand, and coarse aggregate size were experimentally examined, and the results were evaluated using statistical analysis. It was observed that replacing 8% of coarse aggregate with sand and using a higher W/C resulted in higher strength and an improvement in the freeze-thaw durability. Although the positive effect of airentraining admixture (AEA) on freeze-thaw durability of pervious concrete has been manifested by previous researchers, it was not clearly observed in this study. Also, change in coarse aggregate size did not significantly affect the strength and freeze-thaw durability of pervious concrete. This study revealed that the conditions and number of cycles used in JC446-91 were inadequate to evaluate the freeze-thaw durability of pervious concrete, especially for strong mixes. Therefore, considering the criticisms against ASTM C666 in representing field conditions of pervious concrete, more compatible and realistic test methods are required to evaluate the freeze-thaw durability of pervious concrete.

Automated summary

This study focused on evaluating the freeze-thaw durability of pervious concrete specimens using the JC446-91 test method, finding that replacing 8% of coarse aggregate with sand and using a higher water to cement ratio resulted in higher strength and improved freeze-thaw durability. While previous research showed a positive effect of air-entraining admixture on freeze-thaw durability, it was not clearly observed in this study. Additionally, changes in coarse aggregate size did not significantly affect the strength and freeze-thaw durability of pervious concrete. The study revealed that the conditions and number of cycles in JC446-91 were inadequate for evaluating freeze-thaw durability, especially for robust mixes, suggesting a need for more compatible and realistic test methods.