混凝土外文翻譯---力學性能和熱性能評價超高纖維鋼筋混凝土的工程應用

1、外文原文二Mechanical and thermal evaluation of Ultra High Performance Fiber Reinforced Concretes for engineering applicationsValeria Corinaldesi ?, Giacomo MoriconiDepartment of Materials and Environment Engineering and Phy

2、sics, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, ItalyAbstract：Ultra High Performance Fiber Reinforced Concrete (UHPFRC) is a cement-based material, which behaves like a low-porosity cera

3、mic material with excellent mechanical performance. This work was aimed to study soft cast (flowable at casting time) UHPFRC s and, in particular, the time development of compressive strength, flexural strength and elast

4、ic modulus was monitored for UHPFRC prepared by varying the water to cement ratio from 0.20 to 0.32. Silica fume, steel fibers and acrylic-based superplasticizer were employed to prepare the UHPFRC mixtures. Optimum work

5、ability and mechanical performance were obtained with a water to cement ratio of 0.24. Thermal conductivity was determined for the same UHPFRC, in the presence and in the absence of steel fibers. The scope was to evaluat

6、e the effect of steel fibers on the thermal conductivity coefficient, in order to predict the UHPFRC capacity for heat loss. This information as well as its drilling characteristics, in order to test its suitability to b

7、e machined, could be essential for possible fields of application such as in mechanical engineering, where UHPFRC materials can be employed as high abrasion-resistant dies in the molding process of metal and polymer prod

8、ucts. Keywords：Machine workability；Mechanical performance；UHPFRC Silica fume；Thermal conductivityrequire very high performance in terms of both mechanical strength and ductility as well as toughness, may be realized wi

9、th UHPFRC materials. As a matter of fact, in Tokyo, owing to a lack of available areas, plans of buildings as high as 1000 m are being reliably studied. In mechanical engineering, high impact-resistant products, against

10、burst or shot, or high abrasion-resistant dies in the molding process of metal products, such as steel sheets, can be successfully developed. Actual dies are characterized by very high unit cost which, for their economic

11、 amortisation, need high volume production lines. This fact, for instance, prevents supply flexibility in relation to coachwork changes in the car industry. The use of UHPFRC materials, depending on the strength level re

12、quirements, can allow the production of cheaper prototypes, and mediumlow volume dies. Remarkable interest is also emerging in the plastics industry for the production of dies, whose requirements could be easily met by a

13、dequately adjusting the mixture composition and proportioning.This work was aimed to study soft cast UHPFRCs, in particular their mechanical performance, their thermal conductivity, in order to predict UHPFRC capacity fo

14、r heat loss, as well as their adaptability to machining processes. In fact, aim of this paper is also to investigate some drilling characteristics of UHPFRC in order to assess the capability of this material to be machin

15、ed by conventional tools.In terms of UHPFRC mixture proportion optimization, the attention was focused on the effect of the type of superplasticizer used and of the water to cement ratio (ranging from 0.20 to 0.32) on UH

16、PFRC performances. In order to reduce the price of producing UHPFRC, local natural sand was used as replacement material for the more expensive silica sand normally used to produce UHPFRC, similarly with the attempt made

17、 by Yang et al. [9]. Generally, due to the limited available resource and the high cost of silica fume, many authors also tried to reduce UHPFRC cost by searching for the substitution of silica fume by other materials wi

18、th similar functions such as ground granulated blast furnace slag (GGBFS) [2–4,10], ultra fine fly ash [2,4,10], rice husk ash [11]. However, in this work the only mineral addition tried was silica fume, besides to cemen