Aging is one of the main contributors for asphalt failure. Oxidation aging is the main cause of long-term deterioration in asphalt pavements as a pavement ages, oxidation stiffens a pavement, making it more susceptible to failure from load and thermal stresses. Slowing a pavement’s oxidative aging would maintain its elastic properties and delay aging problems. There is no performance enhancer in widespread use, acting as an antioxidant that slows the oxidative aging of asphalt binder. The main objective of this research is to investigate the feasibility of using biomass powder derived from rice husks as an antioxidant additive to control the asphalt age hardening. The waste of rice husks was dried at 40°C for 9–11 days. The dried materials was grounded, and sieved to get fine powder. To evaluate the performance of the antioxidant, samples have to be aged according to SUPERPAVE standards (RTFOT and PAV) and physical, chemical, and rheological properties have to be analyzed. The preliminary results of penetration test softening point test shows that adding 4% of rice husks’ powder to 80/100 binder didn’t change the grade of the binder.
Abstract.A number of researches have been done worldwide to evaluate the damage caused by water in bituminous pavements. The use of the retained strength ratios obtained from laboratory moisture damage tests is a useful tool in making quantitative predictions of the related damage caused by water. This study involved laboratory work on the effect of water on the performance of bituminous mixtures. Comparisons are made between the performances of Hot-rolled Asphalt (HRA) bituminous mixtures containing base bitumen of 50pen grade to that of a polymer-fibre reinforced HRA mixture. Two types of polymer fibre were studied, namely polypropylene and polyester and these fibre were added in different concentrations in the bituminous mixtures. Changes in both the cohesive properties of the bitumen and the adhesion of the bitumen to the aggregate surface were observed as a result of exposing the bituminous mixtures to moisture. The effect of polymer fibre reinforcement in bituminous mixtures helps reduce the level of moisture damage. This was evident in the lower moisture susceptibility achieved in the polymer fibre reinforced bituminous mixtures as compared to the control mixture. The additional bitumen in the fibre reinforced mixtures also afforded an increased film thickness on the aggregate particles, thus affording additional protection of the mixtures from moisture. The reinforcement of polymer fibres in bituminous mixtures also acts to decrease the moisture sensitivity of the bitumen to aggregate bonding. This may be due to the strengthening of the wetted binder matrix that helps promote both adhesion and cohesion retention.
This paper discusses the effect of window orientation on the quality of daylight in order to obtain optimum visual comfort in a lecture room in Subang-Kuala Lumpur Malaysia. Visual comfort in buildings is a vital factor to be taken into consideration and has become a priority. Research work is required in order to recognize the limitations, prospects, and challenges of orientation based on working times for daylighting strategy. The lecture room is associated with outdoor and indoor parameters including geographical location, outdoor illuminance, type of sky, orientation, room size, window to floor area, the position of window, reflectance from floor, wall and ceiling and glazing transparent. It is estimated that the window to floor area ratio in a typical lecture room is 20 percent. The investigation was carried out via Radiance in IES(Virtual Environment) for estimating the evaluated daylighting. The hourly and monthly daylight hours have simulated four cardinal orientations windows because students spend most of the daytime in the lecture room. The average amount of the outdoor illuminance in various months and selected hours of 10am, 12pm and 3pm are simulated under overcast sky and intermediate sky condition according to the Subang-Kuala Lumpur Malaysia condition. The research found that the amount of daylight reaching strongly depends on the orientation, month and time of the working hours in a lecture room. The findings in the lecture room indicate that under an intermediate sky without sun, the north-facing window can provide the best daylight throughout the year during working hours. Consequently, the paper offers to designers and building engineers as a guideline to use guidelines for determining the best orientation instead of a simulation program based on orientation, month and time.
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