The paper presents the comparison of friction coefficient results obtained from two types of dynamic devices: SRT-3 (Skid Resistance Tester) and TWO (Traction Watcher One), which are used to evaluate the skid resistance of national road pavements in Poland. The SRT-3 device operates with the locked wheel, equivalent to 100% slip ratio. The TWO is one of the devices which measures longitudinal force with low slip ratio, which for this particular device is 17.8%. The comparative measurements were carried out on 11 test sections. In order to obtain information about the texture of their surface, stationary devices were used. Macrotexture was characterised by the MPD (Mean Profile Depth) parameter obtained through CTM (Circular Tester Meter) measurements. Microtexture was estimated using the coefficient of friction DFT20 at a slip speed of 20 kph using a DFT (Dynamic Friction Tester) device. This has been proved by the functional relationship between the friction coefficient obtained from the individual dynamic device and the parameter describing the macrotexture and microtexture. A very good linear relationship between friction coefficient obtained from measurements using SRT-3 and DFT at all tested speeds was observed. The SRT-3 is sensitive to microtexture changes in the pavement but not to macrotexture. Friction coefficients obtained from TWO measurements at the test speed 30 kph is more sensitive to microtexture than macrotexture, but at the test speed of 60 and 90 kph it depends both on macrotexture and microtexture. It is caused by type of measured tyre. The SRT-3 is equipped with a ribbed tyre while the TWO has a smooth tyre. In addition, the need to implement stationary devices CTM and DFT as reference devices determining parameters related to texture, for comparative tests of dynamic devices.

Evaluation of skid resistance could be based on both microtexture and macrotexture. It is possible to measure this parameter using CTM (Circular Track Meter) and DFT (Dynamic Friction Tester) devices. Macrotexture is characterized by the MTD (Mean Texture Depth) parameter obtained by CTM measurements. Microtexture can be estimated by the coefficient of friction DFT20 at a slip speed 20 kph using low speed friction measurement devices such as DFT. In this paper the possibility of using CTM and DFT for assessment of wearing course made from SMA (Stone Mastic Asphalt), AC (Asphalt Concrete), Slurry Seal and exposed aggregate PCC (Pavement Cement Concrete) is presented. Eleven test sections were considered. In addition, coefficient of friction μ was measured by SRT-3 device with locked wheel at test speed 30, 60 and 90 kph. Good correlation between DFT20 and μ at tested speeds was observed. It found out that SRT-3 device is more sensitive to microtexture changes in the pavement but not to macrotexture. The influence of asphalt mixture composite, texturing method, polishing resistance of coarse aggregates on skid resistance were analyzed. The measured values of the DFT and CTM devices were used to calculate the IFI numbers for each test section according to the ASTM E1960-07(2011) standard. In addition based on IFI, the coefficient of friction F(S) was calculated at various slip speeds S. Consequently, different pavements surfaces were compared in regard to slip speed S. As the result of the analysis it was found that at low speed pavements made of AC had better skid resistance than SMA and exposed aggregate PCC, while at high speeds SMA and exposed aggregate PCC had better skid resistance than AC pavements. This information is valuable for proper maintenance of existing pavements and on the stage of designing.

The paper presents a comparison of the skid resistance of concrete pavements textured with different techniques in the process of simulating phenomena occurring in actual road conditions. Tests were carried out on five different texturing methods for concrete pavements: burlap drag (BuD), brush drag (BrD), transverse tining (TT), longitudinal tining (LT) and exposed aggregate concrete (EAC). Changes in the skid resistance were recorded by measurements with a British pendulum tester and a circular texture meter before and during the simulation of the abrasion (1st phase of test) and polishing (2nd phase of test) of specimens using a slab polisher. The results of BPN (British pendulum number) and MPD (mean profile depth) allowed us to determine the influence of microtexture and macrotexture on skid resistance. Analysis of variance showed that the method of texturing concrete pavements has a significant influence on the mean BPN values as well as the MPD parameter at each stage of the test. In order to distinguish homogeneous groups in terms of BPN and MPD levels at the particular stages of the process, the Tukey’s HSD (honest significant difference) post-hoc test was performed. It was found that EAC obtained the most favorable results of all the tested pavement types. Due to the high value of the MPD coefficient after the test and the appropriate values of the friction coefficient, it was confirmed that the EAC pavement will be a durable solution due to the guarantee of skid resistance on high-speed roads during its service life.

This article presents the development process of designing and testing poroelastic pavement based on highly polymer-modified bitumen. Poroelastic wearing course was composed of mineral and rubber aggregate mixed with highly polymer-modified bitumen, in contrast to previous trials, during which polyurethane resins were mainly used as binder, which led to several serious technological problems concerning difficult production, insufficient bonding to the base layer, and unsatisfactory durability. The laboratory testing phase was aimed at finding the proper composition of the poroelastic mixture that would ensure required internal shear strength and proper bonding of the poroelastic layer with the base layer. After selecting several promising poroelastic mixture compositions, field test sections were constructed and tested in terms of noise reduction, rolling resistance and interlayer bonding. Despite the very good acoustic properties of the constructed poroelastic wearing course, it was not possible to solve the problem of its insufficient durability. Still, the second major issue of poroelastic pavements that concerns premature debonding of the poroelastic layer from the base layer was completely solved. Experience gained during the implementation of the described research will be the basis for further attempts to develop a successive poroelastic mixture in the future.

The paper presents the evaluation of skid resistance of pavements in their early life on the basis of macrotexture and microtexture changes determined with the Circular Texture Meter (CTM) and the Dynamic Friction Tester (DFT). Tests were performed on two test pavement sections made from exposed aggregate concrete on S8 expressway located in Poland. The relevant parameters, namely the Mean Profile Depth MPD and the friction coefficient DFT20 were measured after two and six weeks from pavement construction and then after three and sixteen months of traffic loads. No changes to the macrotexture were observed in these periods. However, significant changes were observed in the microtexture. The lowest values of DFT20 were determined two weeks from paving, indicating the effect of increased slipperiness just after placement. This lower initial friction coefficient DFT20 can be attributed to the presence of curing agent residue. Such residues are gradually removed from the pavement surface by weathering and trafficking and then the value of DFT20 stabilizes and stays constant at a certain level. The coefficient of friction decreased by ca. 20% in the period between the third and the sixteenth month of trafficking. Finally, the results of evaluation were compared with the classification system developed in the U.S., based on the International Friction Index IFI.