"ageing index" is a correct and usable phrase in written English.
It is typically used in the field of demographics and statistics to measure the changing age composition of a population over time. Example: The ageing index of our country has been steadily increasing over the past decade, indicating a growing proportion of older adults in the population.
Ageing index values show that the susceptibility to oxidative ageing is significantly reduced with the increase of nano-silica content, particularly in the case of long-term ageing.
Based on a correlation analysis between the demolition waste estimates and indicators such as population density, buildings ageing index, buildings density and land occupation type, relationships are established that can be used to determine demolition waste outputs in a given area.
An ageing index is proposed to show that the rejuvenators are affected differently by ageing.
Amount of oxygen uptake corresponds to ageing index expressed by the viscosity ratios after and before ageing.
In infrared spectra analysis, the structural evolutions of binder under different ageing modes were characterized by using right ageing index and the conclusions of thermal analysis and dynamic viscosity tests were confirmed further by the changes of butadiene and carbonyl indexes.
The Vietnamese ageing index, the number of persons 60 years or older per hundred persons under age 15, increased from 18.2% in 1989 to 37.0% in 2007 [ 6].
The RTFO aging index, absolute drop of complex viscosity and temperature aging indices were used to evaluate the bitumen preparation settings.
According to the rheological test, SBS-90 shows a larger complex modulus aging index and a smaller phase angle aging index than that of SBS-70.
Due to the UV aging, LDHs modified bitumen shows the lower softening point increment, viscosity aging index and complex modulus aging index in comparison with the unmodified bitumens, indicating their good UV aging resistance.
The aging index of asphalt and deterioration of SBS modified asphalt increase dramatically at UV aging temperature condition of 70 °C.
As a result of UV aging, softening point increment and viscosity aging index of bitumen were decreased by inorganic nanoparticles.
