Susceptibility Of Mixtures Research Articles

Effects of short-term ageing scenarios on asphalt mixtures’ fracture properties using imaging technique and response surface method

ABSTRACT This paper evaluates the fracture properties of mixtures subjected to different short-term ageing conditions obtained from semi-circular bending test. Response Surface Method (RSM) was used to develop an experimental matrix based on the central composite design. Ageing temperature, ageing duration and duration in humidity and ultraviolet chamber were selected as short-term ageing parameters, while fracture toughness or stress intensity factor (K), broken aggregate (BA) and adhesion failure (AF) were regarded as responses. Image analysis technique was employed for quantification of failures (including adhesion and cohesion failures) on the fractured surface of mixtures. The susceptibility of mixtures’ fracture properties to temperatures was also determined in terms of KTS. The responses were analysed using RSM. The results showed that ageing temperature and ageing duration were the dominating ageing factors affect responses. Ageing increment resulted in higher K and BA while exhibited contradictory effects on AF. Test temperature increment reduced the fracture toughness. The KTS was increased at higher temperatures. Lastly, RSM and image analysis technique exhibited great reliability and capability to study the behaviour of the responses exposed to various ageing conditions.

Laboratory investigation of moisture susceptibility of long-term saturated warm mix asphalt mixtures

Moisture damage in flexible pavements might cause stripping in asphalt pavements and ultimately result in premature failure. Warm mix asphalt (WMA) technology as a means to decrease the energy consumption and emissions associated with conventional hot mix asphalt production is broadly being used recently. However, the utilisation of the hydrated lime and liquid anti-strip additives in WMA mixtures makes these issues more complicated. The objective of this study was to investigate and evaluate the moisture susceptibility of mixtures containing anti-stripping agents (ASAs) and WMA additives after long-term saturated durations. The experimental design for this study included the utilisations of one binder source (PG 64-22), three ASA additives and control, two WMA additives and hot mix, and three aggregate sources. A total of 36 types of mixtures and 540 specimens were fabricated and tested in this study. The performed properties included indirect tensile strength (ITS), tensile strength ratio, flow and toughness. The results indicated that the aggregate source has an effect on dry ITS and flow values but had no effect on wet ITS, wet flow and toughness values. In addition, hot mixture generally had higher dry and wet ITS values, and there were significant differences in flow and toughness values between hot and warm mixtures. Moreover, the hydrated lime exhibited the best moisture resistance in WMA mixtures; the liquid ASA additives could increase the ITS values of mixtures but exhibited a weak moisture resistance in this study. Furthermore, the storage and saturated duration generally had no effect on ITS values, and statistical analysis results did not show any differences among these mixtures.

The Diamagnetism of Some Organic Binary Mixtures at Different Temperatures

Measurements of the magnetic susceptibilities of mixtures consisting of binary combinations of carbon tetrachloride, benzene and nitrobenzene, made with the improved manometric balance of Wills and Boeker over the range of temperatures from 10\ifmmode^\circ\else\textdegree\fi{}C to 50\ifmmode^\circ\else\textdegree\fi{}C, are described. The results for mixtures of benzene and nitrobenzene, each of which shows no variation of mass susceptibility with temperature, show that the principle of additivity of susceptibilities is valid within the limits of precision of measurement. For mixtures of either benzene or nitrobenzene with carbon tetrachloride, a systematic deviation from additivity is found. The deviations for both groups show a definite dependence upon both concentration and temperature.

Magnetic Susceptibility of Mixtures of Solutions

Magnetic Susceptibility of Mixtures of Solutions