Optimum Replacement Ratio for Absorbent Paving Concrete for Sidewalks Containing Zeolite Aggregates† - Absorption Performance and Strength Test Result -

This paper is a basic study on replacing ordinary aggregates with zeolite aggregates with high absorption rates in paving concrete for sidewalks. In order to determine the optimal replacement ratio of coarse and fine zeolite aggregates in paving concrete, absorption performance through absorption and drying tests and mechanical properties through compression, bending, and splitting tensile strength tests were investigated. As a result of the absorption tests, the absorption performance, which can be defined as the difference between absorption rate and drying rate, was 6% for coarse aggregates, which was about 4% higher than that of normal aggregates, and 31% for fine aggregates, which was about 11% higher than that of normal aggregates. In addition, in paving concrete mixed with zeolite aggregates, the absorption rate was up to 4.5%, and the drying rate was at least 0.72%, which showed a relatively high absorption performance considering the unit volume weight. The compressive strength of paving concrete mixed with zeolite aggregate decreased at some replacement ratios compared to that of normal aggregate, but all satisfied the design compressive strengths specified in the Korean design standard. The flexural strength also decreased by up to 16% depending on the replacement ratio and was lower than the design flexural strength specified in the mixture design guidelines. However, it was judged that there would be no problem in applying it to concrete pavement for sidewalks with small design loads. The splitting tensile strength, which is important for crack resistance, was the same or decreased at a rate of 6% or less depending on the replacement ratio, so it is considered to be suitable for paving concrete for sidewalks. From the research results on absorption performance and mechanical properties, it was confirmed that zeolite aggregates can be applied to absorbent paving concrete for sidewalks, and the optimal replacement ratio for this was determined to be 20% coarse aggregate and 10% fine aggregate based on a total of 30% replacement.