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The skid resistance performance of surface aggregates can be assessed in the laboratory with a polishing device that is designed to simulate traffic polishing actions, coupled with a skid resistance measuring device. The standard laboratory test has historically been the polished stone value (PSV) test, as specified in British Standard EN 1097-8:2009. However, as the technology has advanced and traffic volume and composition on the roads have changed, other devices and methodologies have been developed in an attempt to provide better assessment of the skid resistance performance of surface aggregates. This study compared two alternative laboratory tests, the Auckland pavement polishing device (APPD) and the Wehner–Schulze (WS) devices, in assessing the skid resistance performance of three New Zealand greywacke aggregates. This paper discusses the variations in APPD and its corresponding skid resistance measuring device, the dynamic friction tester (DFT) and the effect of macrotexture in the APPD-DFT test. The results demonstrate a good relationship between the APPD-DFT and PSV tests and no relationship between the WS and PSV tests. However, the APPD and WS tests correlate well. The study used only three greywacke aggregates; therefore, no conclusive results can be drawn on the relationship between these laboratory tests as yet.

To improve the moisture susceptibility of concrete structure that will be exposed to water, an admixture should be added. One of the additives that can be added is Xypex C-1000 NF, which a crystalline material. A number of past studies have shown that this additive is effective in improving the moisture resistance of concrete structure. However, the application of this additive in Indonesia was found to be challenging as the performance of the concrete mixture was not as good as expected. This research aims to evaluate the effect of adding various percentages of this additive, various amount of water to be added to the concrete mixture, and the methods of mixing the materials, which are wet and dry methods, by looking at both the slump value and the compressive strength of the concrete specimens. From the research results, it was found that the methods used to mix the additive matter to produce a desirable concrete quality. The wet mix method is the preferable method as it produces less variations in compressive strength test results regardless of the additional water amount. It was also found that, by using both dry and wet mix methods, the usage of Xypex C-1000 NF can improve the compressive strength value.

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