Chip sealing macro texture performance evaluation using split-plot repeated measures

Chip seal is a pavement preservation technique that is preferred by agencies to defer future rehabilitation activities. The objective of this paper is to provide a very beneficial yet simple way to examine the effectiveness of chip seal as a pavement preservation technique and understand the effect of factors such as seal type, age of pavement and their interaction effect on performance. The research provides a carefully designed experimental plan to evaluate chip seal macrotexture properties using a split-plot repeated measurement (SPRM) statistical analysis. Selected emulsified and hot applied roadways in Klamath Falls were examined for their mean texture depth (MTD) using sand circle testing procedure at four consequent time points: (pre-seal application, within one week of seal application, 1-year, and 2-year post-seal application). Findings show that using chip seal have led to a statistically improved macrotexture performance of sealed roadways when compared to their pre-seal texture condition. Both emulsified and hot applied roadways have acquired satisfactory performance during the two-years monitoring period. Statistical analysis results further showed that both seal type and the environmental aging of pavements had a significant effect on roadways mean texture depth values. The study further emphasised that the interaction effect of seal type and time of experimentation had a very significant effect on the MTD performance.

Automated summary

The study demonstrates that chip seal can significantly improve the macrotexture performance of sealed roadways, with seal type and pavement aging having a significant impact on mean texture depth values. Additionally, the interaction effect of seal type and experimentation time has a very significant effect on performance.