Ability of rotary compactor in compacting consistent slabs and effect of rotary compaction on engineering properties of stone mastic asphalt mixtures

A new automatic rotary compactor and its abilities in compacting stone mastic asphalt(SMA) are presented. Following an overview of the rotary compactor and the compaction procedure, it is demonstrated that the rotary compactor is able to produce uniform slabs with the desired thickness of 65 mm all over around. Furthermore, 132 cored samples from the rotary compactor had been compacted uniformly with approximately 4% optimum air void content. In addition, performance tests results indicate that the rotary compactor produces asphalt mixtures with the requirements of resilient modulus, Marshall stability and flow. A weight factor was introduced for each fraction of aggregates in the degradation analysis to compensate the crushing effect of aggregates during mixing and compacting.

Effect of Various Additives on the Low Temperature Performance of Petroleum Based Asphalt Binders

Transverse cracking is a prevalent problem that occurs in asphalt pavement binders in cold climates and diminishes the integrity of the road as well as shortens the life span of the road leading to premature failure.Current specification for testing petroleum asphalt binders for transverse and low temperature cracking is not elaborate enough to accurately model the engineering behaviour of the binders.Besides,neat asphalt derived from petroleum crude oil does not seem to perform well at certain low temperatures without some modification to it.Thus,a study was to be undertaken to determine the low temperature behaviour of 60-70 penetration neat binder modified with traditionally used materials such as Crushed Lime Stone Powder(CLP),Hydrated Lime(HL)and Cellulose Oil Palm Fiber(COPF)at temperatures 0°C,-5°C and-10°C.The study was carried using the state of the art Bending Beam Rheometer(BBR)to assess the stiffness value,m-value and deflection level.The tests were performed in accordance with AASHTO T 313-12 specification.The results of the penetration,rotational viscosity and softening point showed that all of the modified binder specimens are within the required range.However,the performance assessments on the modified petroleum binders with additive materials showed a varied nature with CL powder being the best and the COPF the lowest.It was also observed that the crushed lime stone powder had an increase in stiffness,reduction in deflection and m-value.

Performance of Recycled Ceramic Waste as Aggregatesin Asphalt Mixtures

Ceramic waste materials are abundantly available in Malaysia from the production of ceramic tiles.In general,ceramic materials seem to possess low thermal conductivity characteristics that could reduce pavement temperatures when used as aggregates in asphalt mixtures.A study was undertaken to look into the performance of crushed ceramics incorporated in asphalt mixtures to replace the conventional granite aggregates from sizes 5.0 mm down including the 75 micron filler.The replacement was done proportionally with 0%,20%,40%,60%,80%and 100%ceramic aggregates by weight of granite.Several mix designs with various percentages of ceramic aggregates were formulated to determine the marshal properties such as stability,flow,and resilient modulus.In addition,the potential of ceramic aggregates in reducing the asphalt pavement temperatures was also studied.The outcome of the study showed that the ceramic aggregates in the asphalt mixtures were able to improve the performance of the mixture up to 20%which means there is a great potential for the use of it in road construction.Besides that,the rate of heating(RoH)compacted samples subjected to various temperatures dropped significantly as compared with the control granite specimens.The fatigue performance of the compacted and temperature conditioned ceramic asphalt mixtures displayed an interesting trend in terms of strain resistance at elevated temperatures.