Advanced Materials Research Vol. 723

Abstract: Circulating Fluidized Bed (CFB) Boiler is a means of energy-generating process by burning petroleum coke. In order to avoid blazed petroleum coke with high sulfur content from emitting overdosed sulfur dioxide, limestone is introduced in the boiler for desulfuration. The residue collected from the boiler is called CFB ash. In accordance with different boiler position, CFB ashes can be classified as fly ash and bed ash, and both have similar chemical compositions, with high contents of gypsum and calcium oxide. In this study, CFB ash (fly ash) is mixed with blast furnace slag (BFS) as a substitute for cement in making concrete. It is intended that CFB ashes can be used in concrete and a method for proportioning CFB ash in concrete can be developed. The results show that CFB ash can react with cement to produce hydration products such as Ca(OH)₂, and bring the activation of blast furnace slag. The paste strength could be low at later ages, if the CFB ash content is too low. Whereas, if the CFB ash content is over 30%, the paste strength will be low at the early age. Therefore, it is concluded that the cement-granulated blast furnace slag system will show best performance at the CFB ash content between 18% and 22%. In autoclave soundness test shows the CFB ash of the high f-CaO content is easy reaction in the water, and also did not negatively affect the quality of the volume stability.

Abstract: This paper reviews modern technologies for the recycling of asphalt, which is a key element for effective use of resources. The major goal of the industry is to create a true recycling, meaning that the reclaimed asphalt is used in the same road layer where it has been used before. This requires the ability to produce high-quality asphalt while incorporating high-ratios of reclaimed asphalt. Depending on the situation of the regional road construction industry different strategies for re-using reclaimed asphalt are appropriate. In this paper, we provide an overview on best practices for recycling on asphalt mixing plants.

Abstract: New technologies enable the manufacturing of asphalt at reduced temperatures. As a result The energy consumption per ton of asphalt and the emissions at the road construction site drop significantly. Whilst conventional asphalt is produced at around 170 ° C, the low - temperature processes of today allow production temperatures of around 100 ° C. Various technologies for this are ready for application by road construction industry. Foam bitumen, waxes and other additives, special bitumen or alternative mixing cycles can be suitable for use, depending on the application. Changing the way of asphalt production in an industry takes several years or even decades. In this paper, we will present low temperature asphalt technologies based on the promising technology of foam bitumen and how they are applied in practice.

Abstract: The purpose of this paper is to study the pavement performance of warm-mix recycled SMA mixture. This paper presents a comparative study on performances of aged mixture and warm-mix recycled SMA adding regenerator and warm-mix agent. The results of air void content show that the best mixing temperature of warm-mix recycled SMA mixture is 140 degree centigrade. The Marshall stability, flow number, Marshall residual stability, indirect tensile strength ratio after freezing and thawing and dynamic stability before and after recycling are obtained from laboratory tests. The performance of recycled mixtures is better than aged mixture in all indicators except dynamic stability. The fatigue life of warm mix-recycled modified SMA mixture is 1.5~2.6 times as the aged ones in various stress levels. All indicators meet specification requirements. The conclusion is that the fatigue properties and long-term performance of warm-mix recycled SMA mixture can be improved after recycling with small sacrifice in rutting resistant. The introduction of warm mix agent extends the construction period in winter of the hot in-place recycling and reduces the secondary aging.

Abstract: On August 9, 2009, Typhoon Morakot struck Taiwan, triggering landslides and debris flows and destroying transportation infrastructure in the southern mountains. Many settlements in this area were isolated due to road closure. Residents were trapped in the settlements and unable to evacuate to safe places. Also, emergency goods were unable to be transported to the settlements. In order to minimize the loss of life and property associated with future typhoon, public administrators should evacuate residents before access routes to settlements are affected.In this study, settlements in Lao-Nong River basin of Southern Taiwan were ranked in accordance to isolation susceptibility. Susceptibility was estimated by overlaying maps of landslides, debris flows, temporary roads and primary mountain road layers. Criteria used to evaluate the isolation susceptibility were developed using an expert-based approach. The isolation susceptibilities of settlements were categorized into 3 levels, namely high, moderate and low.

Abstract: In Japan, drainage asphalt pavement (DAP) is widely used especially on the highway and the express way. However, because of the existing porous asphalt materials consist of DAP use polymer modified bitumen, and the aggregate gradation of DAP is differ from conventional mixture, it is difficult to use those porous asphalt materials as the recycled aggregate for reclaimed asphalt pavement. Therefore, the recycling method for recycled DAP which were consisted of recycled porous asphalt materials and virgin aggregates has not been established yet. This paper describes that the recycling method for recycled DAP was considered, and the workability and five years durability was also verified by trial construction of the recycle DAP and new DAP which were consisted of virgin aggregate on the national highway.

Abstract: This study was to perform the viscosity test of adding different ratios (from 10% to 40%) of three recycling agents (RAs), namely RA25, RA75 and RA250, to the reclaimed asphalt binder (RAB) containing a viscosity of 42800 poises. The purpose of the study was to determine the effects of various RAs on the viscosity of aged asphalt binders. The viscosity values were also estimated based on the recycling model of aged asphalt binder developed by authors and the equations developed by Arrhenius (1887), Grunberg and Nissan (1949) and Epps et al. (1980). The results show that there are significant variations in the viscosity of recycling asphalt binder when being added different ratios of RA. The estimated viscosity values computed by the recycling model of aged asphalt binder are closer to the tested results when compared with the equations developed by Arrhenius (1887), Grunberg and Nissan (1949) and Epps et al. (1980). Furthermore, the Recycling Index (RI) developed by the recycling model of aged asphalt binder can clearly and precisely reveal the recycling performance of different kinds of RAs. The G_mix from the equation developed by Grunberg and Nissan (1949) has an apparent effect on estimating the viscosity when adding RA to the RAB.

Abstract: This study investigate permeable pavement utilization and its impact on air temperature by using site measurement, statistical analysis, and Computational Fluid Dynamics (CFD) simulation. National Central University (NCU) main library is the case study for the simulations. Simulations on five pavement types (dense grade asphalt concrete/DGAC, permeable asphalt concrete/PAC, concrete, permeable interlocking concrete block/PICB, and grass block) shows that grass block and PICB can reduce air temperature, while three others increase air temperature.

Abstract: Colored asphalt concrete refers to asphalt concrete pavement that pigments are added in or colorful stones are mixed with, pigments added de-colored petroleum resin asphalt pavement, or modified asphalt pavement with water permeability sprayed with colorful resin coating. It is indispensable to develop traffic safety and embellish street environment. Taiwan is a tropical island. In summer, black pavement absorbs heat and produces greenhouse effect, which is called the heat island effect. Due to the weather factors or outer forces, it is difficult to refill or repair the pits or holes on colored asphalt pavement. The aim of this study is to develop a repairing material package by using Marchshall Mix Design to solve the problem of colored pavement repairing. Furthermore, the repairing material package is packed in 40 kg package which is convenient for operation by using simple tools. Ultimately, life quality will be improved as well.

Abstract: Ferrous-nickel slag is an industrial waste material which produced from smelting process of ferrous-nickel uses in manufacturing of stainless steel and ferrous alloy industry, in China Guangdong province itself, it was estimated around 6-7million of ferrous-nickel slag has been produces annually, the common method in order to reutilize ferrous-nickel slag material is by using on cement industry (replace cement material) and as land-filling material. One of the main objectives of this study is to investigate the feasibility of reutilization of ferrous-nickel slag combined with soil improvement method to portion replace conventional construction materials such as sand and granular material on sub-grade or sub-base layer of pavement construction. Strength and swelling properties of ferrous-nickel slag and soil (sand) mixture after treatment with soil improvement agent will be use as main consideration the performances of ferrous-slag nickel material on road construction, includes 4-days soaked California Bearing Ratio (CBR), 7-day Unconfined Compressive Strength (UCS) and also swelling behaviour of the mixture.