Aggregate-Exposing Operation Parameters, Laboratory and Road Performances of Exposed-Aggregate Concrete Pavement Applied in Long Tunnel

In this paper, exposed-aggregate concrete (EAC) samples, including EAC1 samples with a small aggregate size and EAC2 samples with a large aggregate size, were prepared. The effects of ambient temperature on the waiting time for the spraying of the aggregate-exposing agent (AEG) and the waiting time for the brushing of surface mortar were studied. Furthermore, the optimate spraying dosage of the AEG was determined, and a comparison was undertaken between the antiwearing properties of EAC1, EAC2, and grooved concrete samples. The correlation between the proposed aggregate-exposing depth (AED) indicator and the mean texture depth (MTD) indicator was examined in this study. Stone Mastic Asphalt-13 (SMA-13), EAC1, EAC2, and grooved concrete pavements were paved in a long tunnel, and their macrotexture, skid resistance, noise reduction, and antiglaring performance were compared. As per the results, a good, linear correlation was established between the AED and MTD indicators. With the increase in ambient temperature, the disappearance time of water film on the surface of cement concrete continues to shorten. The earliest, optimum, and latest waiting times for the brushing of EAC are significantly advanced, and the brushing window period continues to shorten. The recommended spraying dosage of 6 % AEG solution is 250-300 g/m2. Under the same spraying dosage of AEG solution, increasing the aggregate size improves the macrotexture of the EAC surface. Note that the skid resistance performance of EAC is not necessarily proportional to its macrotexture. Significantly large aggregate size is disadvantageous to the skid resistance performance of the pavement. The anti-attenuation performance of macrotexture, skid resistance performance, noise reduction performance, and antiglaring performance of EAC pavements are similar to that of the Stone Mastic Asphalt-13 (SMA-13) pavement and significantly better than those of grooved pave-ment. Moreover, the aforementioned performances of EAC1 pavement with small particle size are found to be better.