Issue34

X. Zhengbing et alii, Frattura ed Integrità Strutturale, 34 (2015) 574-579; DOI: 10.3221/IGF-ESIS.34.63 579 damage materials varies more significant, leading to smaller pieces, when specific absorption value becomes higher. Hence we confirm that, the dynamic damage mechanism of concrete and rock materials is that, two materials are in a dynamic instability state when carrying impact load; large energy absorbed by unit volume of material will result in severe damage. As energy absorption ability is determined by properties and strain rate of material, sandstone has a stronger energy absorption ability than concrete. C ONCLUSIONS hree points can be summarized from the test results. Firstly, dynamic mechanical performance of concrete and sandstone is in a close correlation with strain rate and dynamic compressive strength and peak strain is positively correlated to strain rate, i.e., the former increase with the increase of the latter. Secondly, dynamic compressive strength of two materials is approximately in linear correlation with strain rate, and peak strain and strain rate has a second order correlation, concrete is more obvious than rock. The last point is that, dynamic damage mechanism of two materials is actually a dynamic instability process produced after absorbed impact load and damage becomes severer as energy increases; the ability of energy absorption is usually determined by characteristics and strain rate of materials. We conclude from the above three points that, concrete is more suitable to be used as building material than rock materials. However, selection of material is affected by multiple factors in the process of engineering construction; therefore, construction material should be chosen according to local conditions. R EFERENCES [1] Huang, L.X., Development and new achievements of rock dynamics in china, Rock and Soil Mechanics, 2(10) (2011) 2889-2900. [2] Hong, L., Li, X.B., Ma, C.D., Yin, S.B., Ye, Z.Y., Liao, G.Y., Study on size effect of rock dynamic strength and strain rate sensitivity, Chinese Journal of Rock Mechanics and Engineering, 27(3) (2008) 526-533. [3] Xu, J.Y., Li, W.M., Fan, F.L., Bai, E.L., Experimental study on impact properties of carbon fiber reinforced geopolymeric concrete using a SHPB, Journal of Building Materials, 13(4) (2010) 66-69. [4] Wu. J.H., Yu, H.Y., Li, Q., Jiang, Y.D., Experimental study on axial property for concrete with constant surrounding pressure ratio, Journal of Experimental Mechanics, 22(2) (2007) 142-148. [5] Zhi, L.P., Xu, J.Y., Liu, J.Z., Liu, S., Study on dynamic mechanical properties of two rocks under SHPB experiment. Building Science Research of Sichuan, 38(4) (2012) 111-114. [6] Jiao, C.J., Sun, W., Gao, P.Z., Study of steel fiber reinforced high strength concrete subject to blast loading, Engineering Mechanics, 25(3) (2008) 158-166. [7] Xu, J.Y., Liu, S., Fractal features of marble pieces in impact loading test, Rock and Soil Mechanics, 3(11) (2012) 3225- 3229. [8] Shao, M.S., Li, L., Li, Z.X., Elastic wave velocity and mechanical properties of sandstone under different water content at longyou grottoes, 29(supplement) (2010) 3514-3518. [9] Huang, Z.P., Tang, C.A., Zhao, W., Numerical simulation of rockburst failure induced trans i ent unloading under different axial stress, Journal of Northeastern University, 32(6) (2011) 859-863. [10] Li, S.J., Geological natural of rock and its deduction for rock mechanics, Chinese Journal of Mechanics and Engineering, 28(3) (2009) 433-450. T