Long-Term Performance of Diamond Grinding

Diamond grinding (DG) has been used by various districts to improve skid resistance (reduce accidents and fatalities) and improve ride quality [reduce international roughness index (IRI)], with the added benefit of reducing tire/pavement interface noise. The Texas Department of Transportation has used DG on both jointed concrete pavement (JCP) and continuously reinforced concrete pavement (CRCP). This study performed crash accident analysis both before and after DG on a recent project section. After the completion of DG, the occurrences had reduced by approximately 62 and 46% for fatalities and incapacitating injuries, respectively. There was an average IRI reduction of approximately $44\mathrm{in.}$ ($0.70\mathrm{m}/\mathrm{km}$), or 40%, immediately after treatment. This study also analyzed eleven projects to derive a statewide trend on various surface characteristics of pavements due to DG, with the oldest section studied approximately eight years after treatment. Immediately after DG, the average skid number (SN) increased 5.6, or by about 30%. Depending on the existing pavement conditions, the range of the increase in SN varies from 1 to 18. Similarly, there was an average IRI reduction of approximately $0.95\mathrm{m}/\mathrm{km}$ ($\text{60\hspace{0.17em}\hspace{0.17em}}\mathrm{in.}/\mathrm{mi}$) immediately after the DG, or about 40%. Depending on the existing pavement conditions, the range of IRI reduction varies from $0.32–1.94\mathrm{m}/\mathrm{km}$ ($20–122\mathrm{in.}/\mathrm{mi}$), or 17–57%. For deterioration rate under the effect of factors such as time and traffic, each year the SN decreases by approximately 2.0 and IRI increases by approximately $0.03\mathrm{m}/\mathrm{km}$ ($1.7\mathrm{in.}/\mathrm{mi}$).