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Guangzhou, China

Luo X.,PLA Air Force Aviation University | Xu J.,PLA Air Force Aviation University | Xu J.,Northwest University, China | Su H.,PLA Air Force Aviation University | And 2 more authors.
Jianzhu Cailiao Xuebao/Journal of Building Materials | Year: 2014

C30 highly fluidized geopolymer concrete(HFGC) was prepared by using slag and fly ash as raw materials and NaOH and Na2CO3 as alkaline activation agent. The strength properties of HFGC under impact loading, including dynamic splitting-tensile and compressive strength, were studied by using φ100 split Hopkinson pressure bar(SHPB) apparatus improved with the pulse shaper technique. The results indicate that dynamic strength properties of HFGC exhibit strong strain rate dependence; for HFGC, strain rate sensitivity threshold under dynamic splitting-tensile condition is 5.027s-1, and under dynamic compressive condition that is 28.89s-1, the strain rate sensitivity of dynamic splitting-tensile strength is higher than that of dynamic compressive strength; the qualitative trend of dynamic strength properties of HFGC are in accord with that of normal concrete, but compared with normal concrete, the strain rate sensitivity of HFGC becomes even higher because of polycondensed network structure, and that can effectively develop the overall strength properties under impact loading. Thus it can be seen that HFGC is strain rate sensitive. Source


Luo X.,PLA Air Force Aviation University | Xu J.,PLA Air Force Aviation University | Xu J.,Northwest University, China | Zhu J.,PLA Air Force Aviation University | And 3 more authors.
Thin-Walled Structures | Year: 2015

A numerical study is made to investigate the energy absorbing rule of thin-walled metal circular tube made of three different materials (steel, copper, aluminum) by using response surface methodology (RSM). At the same time, the application prospect of RSM in terms of the research on the energy absorption rule of energy absorption structure can be explored. The test result shows that, the compression process of thin-walled metal circular tube can be divided into three stages: elastic stage, yielding plateau stage, compact stage; To get the greatest value of average plateau force (APF), a tube with a shorter height and thicker wall should be adopted; To get the greatest length energy absorption (LEA), a tube with thicker wall should be adopted and the ratio of its height and diameter should be as big as possible; To get the greatest specific energy absorption (SEA), a tube with a thicker wall should be adopted and the ratio between its height and diameter should be as big as possible. Thus, it can be seen that, RSM is an advanced experiment design method, and it can be widely used in the research on the energy absorption characteristics of thin-walled metal circular tube and has a promising application prospect in the development of new energy absorbing material and structure. © 2015 Elsevier Ltd. All rights reserved. Source


Xin L.,PLA Air Force Aviation University | Xu J.-Y.,PLA Air Force Aviation University | Xu J.-Y.,Northwest University, China | Li W.,Airport Office | Bai E.,PLA Air Force Aviation University
Materials Letters | Year: 2014

NaOH and sodium silicate-activated slag and fly ash based geopolymer concrete (NSSFGC) and NaOH and Na2CO3-activated slag and fly ash based geopolymer concrete (NNSFGC) with strength grades of C30 were prepared, the dynamic compressive deformation behavior under impact loading was studied contrastly. The results indicate that, the compressive deformation of NSSFGC is greater than that of NNSFGC in the stage of compaction, which indicates that the volume of microdefect of NSSFGC is greater than that of NNSFGC; the elasticity modulus of NNSFGC is larger than that of NSSFGC; NSSFGC has excellent deformation performance. Thus it can be seen that, alkali-activator types have a big impact on the dynamic compressive deformation behavior of GC, and compared to the alkali-activator prepared with NaOH and Na2CO3, the alkali-activator prepared with NaOH and sodium silicate can be beneficial to give full play to deformation property; so it is better to prepare GC with NaOH and sodium silicate, when used in the Earthquake Engineering. © 2014 Elsevier B.V. Source


Luo X.,PLA Air Force Aviation University | Xu J.-Y.,PLA Air Force Aviation University | Xu J.-Y.,Northwest University, China | Li W.,Airport Office
Functional Materials Letters | Year: 2015

Basalt fiber reinforced porous aggregates-geopolymer based cellular material (BFRPGCM) was prepared. The stress-strain curve has been worked out. The ideal energy-absorbing efficiency has been analyzed and the application prospect has been explored. The results show the following: fiber reinforced cellular material has successively sized pore structures; the stress-strain curve has two stages: elastic stage and yielding plateau stage; the greatest value of the ideal energy-absorbing efficiency of BFRPGCM is 89.11%, which suggests BFRPGCM has excellent energy-absorbing property. Thus, it can be seen that BFRPGCM is easy and simple to make, has high plasticity, low density and excellent energy-absorbing features. So, BFRPGCM is a promising energy-absorbing material used especially in civil defense engineering. © 2015 World Scientific Publishing Company. Source


Luo X.,PLA Air Force Aviation University | Xu J.-Y.,PLA Air Force Aviation University | Xu J.-Y.,Northwest University, China | Li W.,Airport Office
RSC Advances | Year: 2015

In order to develop a new energy-absorbing material by using solid waste, a basalt fiber reinforced lightweight aggregate-geopolymer based cellular material (BFRLGCM) is prepared. A quasi-static compression experiment was carried out, the stress-strain curves were calculated, the ideal energy-absorbing efficiency was analyzed and the material's prospects and feasibility of application have been explored. The results show that: the fiber reinforced cellular material prepared on the basis of Dense Packing Theory has successively sized pore structures; the stress-strain curve of the smaller specimen has three stages: the elastic stage, yielding plateau stage, and dense stage, and the dense strain is 0.646; the greatest value of the ideal energy-absorbing efficiency of BFRLGCM is 90.4%, which suggests BFRLGCM has excellent energy-absorbing properties. Thus it can be seen that the raw materials for BFRLGCM are abundant, the manufacturing cost is low, and BFRLGCM is easy and simple to make. With high plasticity, low density and excellent energy-absorbing features, BFRLGCM is a promising energy-absorbing material especially for use in civil defense engineering. What's more, BFRLGCM has unique economical, social and environmental advantages, and the application of BFRLGCM can improve the utilization of solid waste, turning waste into wealth and so realizing a double win. © The Royal Society of Chemistry 2015. Source

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