The fracture behaviour of three fiber reinforced and regular HPC （high performance concretes） is presented in this paper. Two mixes are based on optimization of HPC whereas the third mix was a commercial mix develop...The fracture behaviour of three fiber reinforced and regular HPC （high performance concretes） is presented in this paper. Two mixes are based on optimization of HPC whereas the third mix was a commercial mix developed by CONTEC ApS （Denmark）. The wedge splitting test setup with 48 cubical specimens was used experimentally and the cracked non-linear hinge model based on the fictitious crack model was applied for the interpretation of the results. The stress-crack opening relationships were extracted by using inverse analysis algorithm for various multi-linear softening curves. This showed that the refinement of the softening curves reflects in improved accuracy of the WST （wedge splitting test） simulation in comparison with bi-linear softening curves with acceptable increase of computational time. Furthermore, the fracture mechanics parameters such as COD （crack opening displacement）, fracture energy and characteristic length were experimentally determined. Experiments were performed at 1, 3, 7 and 28 days. Fracture energy, Gf, was found to increase with age, while the characteristic length, Lch, was found to decrease.展开更多
In this paper,based on the material flux analysis model（MFA） and its corresponding theories and algorithms of ＂virtual land＂ virtual land contents of five primary agricultural products are calculated and＂Virtual ...In this paper,based on the material flux analysis model（MFA） and its corresponding theories and algorithms of ＂virtual land＂ virtual land contents of five primary agricultural products are calculated and＂Virtual land trade＂hidden in those imported and exported products are also obtained through analyzing the primary agricultural product trade between China and ASEAN. In the process of calculationl following the thought of Changing agricultural products to ＂Virtual land trade＂land content, trade condition and spatiai distribution of agricultural products Were integratedly considered. indicate that China exported 73;057 km^2 of virtual land area to ASEAN by tea, vegetables; maize and grain, ASEAN exported： 57.332 km^2 to China by natural rubber from 2002 to 2005. It obvious; that china has lost 15,725 km^2 arable land through agricultural product trade, Additionally, in order to process： of calculation Virtual land trade, Thailand taker as an example to analyze its international trade of rice and Wheat from 1991 to 2005 and Calculate their ＂Virtual land trade＂ 2001 through 2005. According to and calculation, it is not difficult to conclude that ＂Virtual land trade＂ very important and could be used for China to guide agricultural export or import Structure and maintain Sustainable use of land resources.展开更多
文摘The fracture behaviour of three fiber reinforced and regular HPC （high performance concretes） is presented in this paper. Two mixes are based on optimization of HPC whereas the third mix was a commercial mix developed by CONTEC ApS （Denmark）. The wedge splitting test setup with 48 cubical specimens was used experimentally and the cracked non-linear hinge model based on the fictitious crack model was applied for the interpretation of the results. The stress-crack opening relationships were extracted by using inverse analysis algorithm for various multi-linear softening curves. This showed that the refinement of the softening curves reflects in improved accuracy of the WST （wedge splitting test） simulation in comparison with bi-linear softening curves with acceptable increase of computational time. Furthermore, the fracture mechanics parameters such as COD （crack opening displacement）, fracture energy and characteristic length were experimentally determined. Experiments were performed at 1, 3, 7 and 28 days. Fracture energy, Gf, was found to increase with age, while the characteristic length, Lch, was found to decrease.
文摘In this paper,based on the material flux analysis model（MFA） and its corresponding theories and algorithms of ＂virtual land＂ virtual land contents of five primary agricultural products are calculated and＂Virtual land trade＂hidden in those imported and exported products are also obtained through analyzing the primary agricultural product trade between China and ASEAN. In the process of calculationl following the thought of Changing agricultural products to ＂Virtual land trade＂land content, trade condition and spatiai distribution of agricultural products Were integratedly considered. indicate that China exported 73;057 km^2 of virtual land area to ASEAN by tea, vegetables; maize and grain, ASEAN exported： 57.332 km^2 to China by natural rubber from 2002 to 2005. It obvious; that china has lost 15,725 km^2 arable land through agricultural product trade, Additionally, in order to process： of calculation Virtual land trade, Thailand taker as an example to analyze its international trade of rice and Wheat from 1991 to 2005 and Calculate their ＂Virtual land trade＂ 2001 through 2005. According to and calculation, it is not difficult to conclude that ＂Virtual land trade＂ very important and could be used for China to guide agricultural export or import Structure and maintain Sustainable use of land resources.
