Study Of Interface Strength Deterioration Of Granite-concrete Sample By Freeze-thaw Cycle

Concrete,a singnificant used material in rock engineering protection.The good bond performance is a main premise between concrete and rock to paly a role in supporting.Howerve,in the process of construction on high altitude,cold regions and artificial freezing,it is a new challenge for the bonding of concrete and rock under the environment of freezing and thawing cycle.In this paper,the strength characteristics of the interface of granite-concrete was studied by experiment,and focusing on the influence of different characteristics and the strength damage of the interface under the freeze-thaw environment.The study can provide a basis reference for the engineering support in the high-altitude and cold region.In this paper,granite was producted samples with different roughness and hydrophilicly interfaces,and symmetrically pour the concrete to make granite-concrete samples.The surface roughness and hydrophilicly were quantitatively measured by the positive approach.Then,the samples was tested with the 0,10,20,30 and 50 times freeze-thaw cycle and mesure the shear strength of the interface.Finally,the fracture morphology of the interface was measured.There are some signification conclusion according to the test results:?After the different times freeze-thaw cycle,the interface of samples produced different degrees of fracture,and the surface of the sample appears some observably phenomena,including fall off,cracking nand so on;?There is a positive correlation between the shear strength and JRC of the granite-concrete interface and a negative correlation with the contact Angle.In addition,the interfacial strength decreased with the increase of freeze-thaw cycles.During the freeze-thaw cycles from 0 to 30 times,the interfacial shear strength decreased at a faster rate,and then it is gradually decreased.?Duing to the complication of hydrophily interface of sample,the fracture morphology of the sample under hydrophilic conditions was measured in detail to analyze the interface and morphological characteristics after the failure,and there is a similar change trend between the the concrete adhesion on the rock surface after the failure and the shear strength was discussed.?The calculation method of the granite-concrete interface shear strength theory put forward,and according to verify between the model formula calculation results and test results,the result is good.