Over the recent years the amount of fast destruction defects of cement paste matrix has increased markedly for exposed concrete structures of highway and airport pavements. The accelerated destruction of silicate structure is unusual due to its irregular occurrence. It only occurs at 30 to 50% of newly built pavements (in continuous segments). The issue is applicable to loaded as well as unloaded pavements. Detailed diagnostics found that the probable cause is based on concurrently occurring expansive reactions in capillaries, cracks and pores in the cement paste matrix. In defect spots the presence of several expansive substances was proven, wherein the biggest question poses the unexpectedly high potassium concentration. Potassium is only contained at best in trace amounts in road concrete input components in the Czech Republic. Neither existing regulations nor standards sufficiently deal with this type of defects of cement concretes. If they mention the existence of this issue at all, they are just limited to recommendations. Since the modification of the existing commercially produced cements to pavements is still improbable, the solutions to this issue seem problematic.

Monolithic as well as precast Portland Cement Concrete pavement have shown a gradual increase in quantity and severity of defects and failures in recent years. Especially, the radical increase in the auto-destructive deterioration of the concrete structure, which is most often described as the expansion reaction, is alarming. The consequences may lead to extreme reduction of the lifetime of concrete on loaded or unloaded surface courses. The main causes are due to the combined effect of environmental effects (climate, chemical pollution), drainage of roads and the behaviour of the existing cement binders, provided that we do not reflect the modification of pavement structure layers. Only the impact of climate effects can be effectively reduced on the existing roads. The paper presents a summary of results obtained from the current portfolio of secondary concrete protection products. The testing was performed in terms of resistance to water infiltration and durability against the common effects of freeze/thaw and salt. The results show a dependence or independence according to the material basis when exposed to secondary protection products. Oils, silicate emulsions and a group with other material bases, so called other products, behave quite differently.

The evaluation of the bearing capacity of asphalt pavements is usually performed by analysing the deflections measured by a Falling Weight Deflectometer (FWD). The deflection changes with the pavement temperature. In evaluation is necessary to consider the thermal gradient of pavement and perform the temperature correction. The article contains an analysis of effects of the pavement temperature on FWD results on the long-term monitored sections. The temperature correction was performed on measured deflections or back-calculated elasticity moduli. The moduli recalculated to the temperature of 20 °C according to both procedures were similar. Comparison of moduli determined by recalculation to moduli backcalculated from the deflection bowls measured at the temperature of 20 °C, has proven smaller differences for the moduli determined from the deflection bowl corrected to the temperature of 20 °C.

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