【正文】 r rutting parameter and better rheological properties than the base asphalt. But the ductility of the modified asphalts decreased with the addition of BT and OBT. They have significantly lower creep stiffness. Therefore, the low temperature cracking resistance was improved by addition of BT and OBT. The OBT modified asphalts has better properties than the BT modified asphalts. E. Nanotechnology in Fire Protection Fire resistance of steel structures is often provided by a coating of spray on cementitious process which is no more popular because they need to be thick, tend to be 14 brittle and polymer additions are needed to improve adhesion. However, research into nanocement (made of nanosized particles) has the potential to create a new paradigm in this area of application. This is achieved by the mixing of carbon nanotubes (CNT‘s) with the cementious material to fabricate fibre posites that can inherit some of the outstanding properties of the nanotubes such as strength. Polypropylene fibres are also being considered as a method of increasing fire resistance and this is a cheaper option than conventional insulation. CNTs can also be used to produce protective clothing materials because of their flame retardant property. of Nanotechnology on Construction A. Merits 1) Compared with conventional TiO2, TiO2 at the nanoscale experiences a 500% increase in surface area and a 400% decrease in opacity. Current nanoTiO2 production levels have reached approximately 4 million metric tons at a price of approximately $45/kg to $50/kg vs. $ 2) The CNT market worldwide is expected to grow from $51 million in 2021 to more than $800 million by 2021 (BCC Research 2021). 3) Nanomodified concrete cuts down construction schedules while reducing labourintensive (and expensive) tasks. Also it can reduce the cost of repair and maintenance. 4) The paint and coatings industry consists of approximately annual sales of $20 billion (Baer et al. 2021). Nanoalumina and titania have a four to sixfold increase in wear resistance, with doubled toughness and bond strength (Gell 2021). 5) The potential global market of nanoposites is estimated at $340 billion for the next two decades (Roco and Bainbridge 2021). 15 6) The market for fire protection systems totalled approximately $45 billion in 2021 and is expected to grow to more than $80 billion by 2021 (Helmut Kaiser Consultancy 2021) 7) Nano sensors embedded in infrastructural materials can provide, at minimum cost, fully integrated and selfpowered failure prediction and forecasting mechanisms for highcapital structures (., reservoirs, nuclear power plants, and bridges). B. Demerits 1) Because of their small particle size, nano particles have the potential to negatively affect the respiratory and digestive tracks and the skin or eye surface [3] thus exposes workers to hazards. 2) Since nanotechnologyrelated industries are relatively new, the type of worker who is employed in construction research and development (or even some field applications) must have an interdisciplinary background. 3) New policies in the context of nanotechnology will require cooperation between various levels of government, Ramp?！睆秃喜牧希?B期33,4號（ 2021）： 263277. 8 外文文獻： Nanotechnology in Civil Engineering [Abstract] The innovation of relevant nanotechnology and its significance in civil engineering practice is illustrated in this paper for broadening vision. It creates materials, devices, and systems with new properties and functions. The role of nanotechnology in the conceiving of innovative infrastructure systems has the potential to revolutionize the civil engineering practice and widen the vision of civil engineering. Following this the analysis were carried out in ductile structural posites along with its enhanced properties, low maintenance coatings, better properties of cementitious materials, reducing the thermal transfer rate of fire retardant and insulation, various nanosensors, smart materials, intelligent structure technology etc. The properties like selfsensing, selfrehabilitation, selfcleaning, selfvibration damping, selfstructural health monitoring and selfhealing are the key features. To execute these, the gap between the nanotechnology and construction materials research needs to be bridged. This paper first presents the background information and current developments in nanotechnology and civil engineering in general followed by the merits and demerits of their interdisciplinary approach. Further the details of application oriented nanotechnologyenabled materials and products that are either on the market or ready to be adopted in the construction industry and also their possible consequences over the time is elucidated. Some of the major instances of current applications of nanotechnology in the field of civil engineering across its different sections around the globe are exemplified. The most challenging economic factors concerned with its practicality are discussed briefly. Finally the future trend, potential and implications of nanotechnology development in civil engineering towards more economical