| In this paper,with rubber-natural pumice concrete as the object of study,we studied the effect of particle size of rubber powder,mixing amount and water to binder ratio on the mechanical properties of concrete and anti-freezing durability by means of orthogonal test.For particle size of rubber powder,20-mesh,60-mesh and 120-mesh powders were chosen,and for mixing amount,3%,6% and 9% were chosen.By analyzing compressive strength,splitting tensile strength and tension-compression ratio of rubber-natural pumice concrete,we found the group with optimal physical and mechanical properties and primary and secondary factors;we also studied the effect of particle size and mixing amount of rubber powder on freezing resistance of rubber-natural pumice concrete.The test indicated that 6% and 20-mesh rubber powder had optimal mechanical performance,and 3% and 120-mesh rubber powder had optimal freezing resistance.We studied the microstructure of rubber-natural pumice concrete and analyzed the relation between mechanical properties and some factors,such as pore spacing coefficient and porosity,through test of pore spacing for hardened concrete,SEM test and CT non-destructive scanning test;failure modes of rubber-natural pumice concrete in freeze-thaw cycles in different erosion medium were compared to proof particle size and water to binder ratio of rubber powder are major factors affecting the anti-freezing performance of rubber-natural pumice concrete.For the saline-alkali environment in Hetao Irrigation Area in Inner Mongolia,we prepared the simulated saline-alkaline solution,studied the anti-freezing performance of rubber-natural pumice concrete in saline-alkaline solution,measured the mass loss rate and relatively dynamic elastic modulus of sample block after several freeze-thaw cycles,analyzed their amplitude rule of variation and discussed the freeze-thaw erosion mechanism of rubber-natural pumice concrete in complex environment. |
PDF Full Text Request